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Müller N, Härtel JA, Schmitz J, Baur U, von der Wiesche M, Rieger I, Gerlach D, von Stritzky J, Bach A, Hart C, Bros J, Seeger B, Zollmann E, Grau M, Dragutinovic B, de Boni LM, Hönemann JN, Bloch W, Aeschbach D, Elmenhorst EM, Herberg U, Hess A, Schumann M, Kratz T, Jordan J, Breuer J, Tank J. Peripheral Oxygenation and Pulmonary Hemodynamics in Individuals With Fontan Circulation During 24-Hour High-Altitude Exposure Simulation. Circulation 2024; 149:1466-1468. [PMID: 38683898 DOI: 10.1161/circulationaha.123.067601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Affiliation(s)
- Nicole Müller
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Julian Alexander Härtel
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Jan Schmitz
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Cologne, Germany (J.S.)
| | - Ute Baur
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Melanie von der Wiesche
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Iris Rieger
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Darius Gerlach
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Jon von Stritzky
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Anja Bach
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Christopher Hart
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Janina Bros
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Benedikt Seeger
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
| | - Emily Zollmann
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
| | - Marijke Grau
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
| | - Boris Dragutinovic
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
| | - Laura-Maria de Boni
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Jan-Niklas Hönemann
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Clinic III for Internal Medicine, Cologne, Germany (J.-N.H.)
- Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care, University of Cologne, Germany (J-N.H., J.J.)
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
| | - Daniel Aeschbach
- Institute of Experimental Epileptology and Cognition Research (D.A.), University of Bonn Medical Center, Germany
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
| | - Eva-Maria Elmenhorst
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
- Institute for Occupational, Social and Environmental Medicine (E-M.E.), Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, Germany
| | - Ulrike Herberg
- Department of Pediatric Cardiology (U.H.), Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, Germany
| | - Alena Hess
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Moritz Schumann
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
- Department of Sports Medicine and Exercise Therapy, Institute of Human Movement Science and Health, Chemnitz University of Technology, Germany (M.S.)
| | - Tobias Kratz
- Department of Pediatric Cardiology (N.M., J.A.H., U.B., C.H., A.H., T.K., J.B.), University of Bonn Medical Center, Germany
| | - Jens Jordan
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
- Medical Faculty, University of Cologne, Albertus-Magnus-Platz, Cologne, Germany (J.J.)
- Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care, University of Cologne, Germany (J-N.H., J.J.)
| | - Johannes Breuer
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany (J.B., B.S., E.Z., M.G., B.D., W.B., M.S.)
| | - Jens Tank
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (J.S., M.v.d.W., I.R. D.G., J.v.S., A.B., L-M.d.B., J-N.H., D.A., E-M.E., J.J., J.T.)
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Smolich JJ, Kenna KR, Mynard JP. Extended period of ventilation before delayed cord clamping augments left-to-right shunting and decreases systemic perfusion at birth in preterm lambs. J Physiol 2024; 602:1791-1813. [PMID: 38532618 DOI: 10.1113/jp285799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 02/26/2024] [Indexed: 03/28/2024] Open
Abstract
Previous studies have suggested that an extended period of ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. However, it is unknown whether this greater rise in PA flow is accompanied by increases in left ventricular (LV) output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale (FO), with decreased systemic arterial perfusion. Using an established preterm lamb birth transition model, this study compared the effect of a short (∼40 s, n = 11), moderate (∼2 min, n = 11) or extended (∼5 min, n = 12) period of initial mechanical lung ventilation before DCC on flow probe-derived perinatal changes in PA flow, LV output, total systemic arterial blood flow, ductal shunting and FO shunting. The LV output was relatively stable during initial ventilation but increased after DCC, with similar responses in all groups. Systemic arterial flow patterns displayed only minor differences during brief and moderate periods of initial ventilation and were similar after DCC. However, an increase in PA flow was augmented with an extended initial ventilation (P < 0.001), owing to an earlier onset of left-to-right ductal and FO shunting (P < 0.001), and was accompanied by a pronounced reduction in total systemic arterial flow (P = 0.005) that persisted for 4 min after DCC (P ≤ 0.039). These findings suggest that, owing to increased left-to-right shunting and a greater reduction in systemic arterial perfusion, an extended period of ventilation before DCC does not result in greater perinatal circulatory benefits than shorter periods of initial ventilation in the birth transition. KEY POINTS: Previous studies suggest that an extended period of initial ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. It is unknown whether this greater rise in PA flow is accompanied by an increased left ventricular output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale, with decreased systemic arterial perfusion. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent a brief (∼40 s), moderate (∼2 min) or extended (∼5 min) period of ventilation before DCC. Perinatal changes in left ventricular output were similar in all groups, but extended initial ventilation augmented both perinatal increases in PA flow, owing to earlier onset and greater left-to-right ductal and foramen ovale shunting, and perinatal reductions in total systemic arterial perfusion. Extended ventilation before DCC does not confer a greater perinatal circulatory benefit than shorter periods of initial ventilation.
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Affiliation(s)
- Joseph J Smolich
- Heart Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Kelly R Kenna
- Heart Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Jonathan P Mynard
- Heart Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
- Department of Biomedical Engineering, University of Melbourne, Parkville, Victoria, Australia
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Xiong J, Liu T, Zheng J, Du L, Lin J. Acute severe pulmonary hypertension during weaning from cardiopulmonary bypass for aortic valve replacement surgery: A case report. Perfusion 2024; 39:635-639. [PMID: 36738123 DOI: 10.1177/02676591231155741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pulmonary arterial pressure (PAH) usually increases after cardiopulmonary bypass (CPB), but this normally does not affect weaning off CPB. Here we report a case of severe PAH in a patient with normal left atrial pressure. Prolonging CPB by 45 min did not lead to lower PAH. Given that lung injury can stimulate secretion of vasoconstrictors that trigger PAH, we decided to gradually increase blood flow into the lungs in an effort to restore the balance between pulmonary vasoconstrictors and vasodilators. Pulmonary artery pressure gradually decreased, allowing the patient to be weaned off CPB, after which she recovered uneventfully. Our experience suggests an approach for managing acute, severe PAH after CPB without the need for mechanical circulatory support.
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Affiliation(s)
- Jiyue Xiong
- Department of Anesthesiology, West China Hospital, Sichuan University and West China Research Unit, Chinese Academy of Medical Sciences, Chengdu, China
| | - Ting Liu
- Department of Anesthesiology, West China Hospital, Sichuan University and West China Research Unit, Chinese Academy of Medical Sciences, Chengdu, China
| | - Jianqiao Zheng
- Department of Anesthesiology, West China Hospital, Sichuan University and West China Research Unit, Chinese Academy of Medical Sciences, Chengdu, China
| | - Lei Du
- Department of Anesthesiology, West China Hospital, Sichuan University and West China Research Unit, Chinese Academy of Medical Sciences, Chengdu, China
| | - Jing Lin
- Department of Anesthesiology, West China Hospital, Sichuan University and West China Research Unit, Chinese Academy of Medical Sciences, Chengdu, China
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Zheng S, Ye L. Hemodynamic Melody of Postnatal Cardiac and Pulmonary Development in Children with Congenital Heart Diseases. Biology (Basel) 2024; 13:234. [PMID: 38666846 PMCID: PMC11048247 DOI: 10.3390/biology13040234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024]
Abstract
Hemodynamics is the eternal theme of the circulatory system. Abnormal hemodynamics and cardiac and pulmonary development intertwine to form the most important features of children with congenital heart diseases (CHDs), thus determining these children's long-term quality of life. Here, we review the varieties of hemodynamic abnormalities that exist in children with CHDs, the recently developed neonatal rodent models of CHDs, and the inspirations these models have brought us in the areas of cardiomyocyte proliferation and maturation, as well as in alveolar development. Furthermore, current limitations, future directions, and clinical decision making based on these inspirations are highlighted. Understanding how CHD-associated hemodynamic scenarios shape postnatal heart and lung development may provide a novel path to improving the long-term quality of life of children with CHDs, transplantation of stem cell-derived cardiomyocytes, and cardiac regeneration.
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Affiliation(s)
- Sixie Zheng
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, National Children’s Medical Center, Shanghai 200127, China;
- Shanghai Institute for Pediatric Congenital Heart Disease, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, National Children’s Medical Center, Shanghai 200127, China
| | - Lincai Ye
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, National Children’s Medical Center, Shanghai 200127, China;
- Shanghai Institute for Pediatric Congenital Heart Disease, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, National Children’s Medical Center, Shanghai 200127, China
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Tucker S, Cornicelli M, Loomba R, Fox J, Wald E, Penk J. Echocardiographic measured shunt velocity does not predict pulmonary blood flow in patients with Blalock-Thomas-Taussig shunt. Cardiol Young 2024; 34:535-539. [PMID: 37529906 DOI: 10.1017/s104795112300269x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
INTRODUCTION Catheterisation is the gold standard used to evaluate pulmonary blood flow in patients with a Blalock-Thomas-Taussig shunt. It involves risk and cannot be performed frequently. This study aimed to evaluate if echocardiographic measurements obtained in a clinical setting correlate with catheterisation-derived pulmonary blood flow in patients with a Blalock-Thomas-Taussig shunt as the sole source of pulmonary blood flow. METHODS Chart review was performed retrospectively on consecutive patients referred to the catheterisation lab with a Blalock-Thomas-Taussig shunt. Echocardiographic parameters included peak, mean, and diastolic gradients across the Blalock-Thomas-Taussig shunt and forward and reverse velocity time integral across the distal transverse aorta. In addition to direct correlations, we tested a previously published formula for pulmonary blood flow calculated as velocity time integral across the shunt × heart rate × Blalock-Thomas-Taussig shunt area. Catheterisation parameters included pulmonary and systemic blood flow as calculated by the Fick principle. RESULTS 18 patients were included. The echocardiography parameters and oxygen saturation did not correlate with catheterisation-derived pulmonary blood flow, systemic blood flow, or the ratio of pulmonary to systemic blood flow. As the ratio of reverse to forward velocity time integral across the transverse aorta increased, the probability of shunt stenosis decreased. CONCLUSION Echocardiographic measurements obtained outside the catheterisation lab do not correlate with catheterisation-derived pulmonary blood flow. The ratio of reverse to forward velocity time integral across the transverse aortic arch may be predictive of Blalock-Thomas-Taussig shunt narrowing; this finding should be investigated further.
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Affiliation(s)
- Sarah Tucker
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Matthew Cornicelli
- Department of Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Rohit Loomba
- Department of Cardiac Critical Care, Advocate Health Care, Chicago, IL, USA
| | - Jeremy Fox
- Department of Interventional Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Eric Wald
- Department of Critical Care, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Jamie Penk
- Department of Cardiac Critical Care, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
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Falk L, Lidegran M, Diaz Ruiz S, Hultman J, Broman LM. Severe Lung Dysfunction and Pulmonary Blood Flow during Extracorporeal Membrane Oxygenation. J Clin Med 2024; 13:1113. [PMID: 38398425 PMCID: PMC10889439 DOI: 10.3390/jcm13041113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/05/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Extracorporeal membrane oxygenation (ECMO) is indicated for patients with severe respiratory and/or circulatory failure. The standard technique to visualize the extent of pulmonary damage during ECMO is computed tomography (CT). PURPOSE This single-center, retrospective study investigated whether pulmonary blood flow (PBF) measured with echocardiography can assist in assessing the extent of pulmonary damage and whether echocardiography and CT findings are associated with patient outcomes. METHODS All patients (>15 years) commenced on ECMO between 2011 and 2017 with septic shock of pulmonary origin and a treatment time >28 days were screened. Of 277 eligible patients, 9 were identified where both CT and echocardiography had been consecutively performed. RESULTS CT failed to indicate any differences in viable lung parenchyma within or between survivors and non-survivors at any time during ECMO treatment. Upon initiation of ECMO, the survivors (n = 5) and non-survivors (n = 4) had similar PBF. During a full course of ECMO support, survivors showed no change in PBF (3.8 ± 2.1 at ECMO start vs. 7.9 ± 4.3 L/min, p = 0.12), whereas non-survivors significantly deteriorated in PBF from 3.5 ± 1.0 to 1.0 ± 1.1 L/min (p = 0.029). Tidal volumes were significantly lower over time among the non-survivors, p = 0.047. CONCLUSIONS In prolonged ECMO for pulmonary septic shock, CT was not found to be effective for the evaluation of pulmonary viability or recovery. This hypothesis-generating investigation supports echocardiography as a tool to predict pulmonary recovery via the assessment of PBF at the early to later stages of ECMO support.
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Affiliation(s)
- Lars Falk
- ECMO Centre Karolinska, ME Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Akademiska Straket 14, 171 76 Stockholm, Sweden; (J.H.); (L.M.B.)
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Marika Lidegran
- Department of Pediatric Radiology, Astrid Lindgren Children’s Hospital, Karolinska University Hospital, 171 76 Stockholm, Sweden; (M.L.); (S.D.R.)
| | - Sandra Diaz Ruiz
- Department of Pediatric Radiology, Astrid Lindgren Children’s Hospital, Karolinska University Hospital, 171 76 Stockholm, Sweden; (M.L.); (S.D.R.)
- Department of Women’s and Children’s Health, Karolinska Institutet, 171 76 Stockholm, Sweden
- Department of Radiology, Lund University, 221 00 Lund, Sweden
| | - Jan Hultman
- ECMO Centre Karolinska, ME Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Akademiska Straket 14, 171 76 Stockholm, Sweden; (J.H.); (L.M.B.)
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Lars Mikael Broman
- ECMO Centre Karolinska, ME Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Akademiska Straket 14, 171 76 Stockholm, Sweden; (J.H.); (L.M.B.)
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 76 Stockholm, Sweden
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Yamamoto S, Sakamaki F, Takahashi G, Kondo Y, Taguchi N, Esashi S, Yuji R, Murakami K, Osaragi K, Tomita K, Kamei S, Matsumoto T, Imai Y, Hasebe T. Retracted: Chest digital dynamic radiography to detect changes in human pulmonary perfusion in response to alveolar hypoxia. J Med Radiat Sci 2023; 70:e1-e11. [PMID: 36101943 PMCID: PMC10715373 DOI: 10.1002/jmrs.619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 08/29/2022] [Indexed: 01/04/2023] Open
Abstract
INTRODUCTION Hypoxic pulmonary vasoconstriction optimises oxygenation in the lung by matching the local-blood perfusion to local-ventilation ratio upon exposure to alveolar hypoxia. It plays an important role in various pulmonary diseases, but few imaging evaluations of this phenomenon in humans. This study aimed to determine whether chest digital dynamic radiography could detect hypoxic pulmonary vasoconstriction as changes in pulmonary blood flow in healthy individuals. METHODS Five Asian men underwent chest digital dynamic radiography before and after 60 sec breath-holding at the maximal inspiratory level in upright and supine positions. Alveolar partial pressure of oxygen and atmospheric pressure were calculated using the blood gas test and digital dynamic radiography imaging, respectively. To evaluate the blood flow, the correlation rate of temporal change in each pixel value between the lung fields and left cardiac ventricles was analysed. RESULTS Sixty seconds of breath-holding caused a mean reduction of 26.7 ± 6.4 mmHg in alveolar partial pressure of oxygen. The mean correlation rate of blood flow in the whole lung was significantly lower after than before breath-holding (before, upright 51.5%, supine 52.2%; after, upright 45.5%, supine 46.1%; both P < 0.05). The correlation rate significantly differed before and after breath-holding in the lower lung fields (upright, 11.8% difference; supine, 10.7% difference; both P < 0.05). The mean radiation exposure of each scan was 0.98 ± 0.09 mGy. No complications occurred. CONCLUSIONS Chest digital dynamic radiography could detect the rapid decrease in pulmonary perfusion in response to alveolar hypoxia. It may suggest hypoxic pulmonary vasoconstriction in healthy individuals.
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Affiliation(s)
- Shota Yamamoto
- Department of RadiologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Fumio Sakamaki
- Department of Respiratory MedicineTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Genki Takahashi
- Department of Respiratory MedicineTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Yusuke Kondo
- Department of Respiratory MedicineTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Naoya Taguchi
- Department of Radiological TechnologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Shogo Esashi
- Department of Radiological TechnologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Ryotaro Yuji
- Department of Radiological TechnologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Katsuki Murakami
- Department of Radiological TechnologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Kensuke Osaragi
- Department of RadiologyKochi University, Kochi Medical SchoolNankokuKochiJapan
| | - Kosuke Tomita
- Department of RadiologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Shunsuke Kamei
- Department of RadiologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Tomohiro Matsumoto
- Department of RadiologyKochi University, Kochi Medical SchoolNankokuKochiJapan
| | - Yutaka Imai
- Department of RadiologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
| | - Terumitsu Hasebe
- Department of RadiologyTokai University Hachioji Hospital, Tokai University School of MedicineTokyoJapan
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Hanaoka J, Hayashi K, Shiratori T, Okamoto K, Kataoka Y, Kawaguchi Y, Ohshio Y, Sonoda A. Relationship between pulmonary blood flow and volume following lung resection using dynamic perfusion digital radiography. J Thorac Dis 2023; 15:5593-5604. [PMID: 37969269 PMCID: PMC10636465 DOI: 10.21037/jtd-23-986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/14/2023] [Indexed: 11/17/2023]
Abstract
Background Surgical intervention for lung resection can cause ventilation-perfusion mismatches and affect gas exchange; however, minimally invasive assessment of blood flow is difficult. This study aimed to evaluate changes in pulmonary blood flow after radical lung cancer surgery using a minimally invasive dynamic digital chest radiography system. Methods We evaluated 64 patients who underwent radical lobectomies. Postoperative changes in pulmonary blood flow, assessed using dynamic chest radiography-based blood flow ratios (BFRs), were compared with the temporal evolution of both functional lung volumes (FLVs) and estimated lung weight (ELW) derived from computed tomography (CT) volumetry. Results FLVs on the affected side gradually recovered over time from the lowest value observed 3 months after surgery in all procedures. BFRs on the affected side also showed a gradual recovery from the lowest value 1 month after surgery, except for left upper lobectomies (LULs). In LULs, FLVs and ELWs increased proportionally up to 3 months after surgery, with lung volumes continuing to increase thereafter. The recovery of BFRs differed depending on the resected lobe. Conclusions A relationship between pulmonary blood flow and FLV was observed in the postoperative period. Despite varying compensatory responses depending on the surgical procedure, FLV recovery coincided with increased pulmonary blood flow.
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Affiliation(s)
- Jun Hanaoka
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Japan
| | - Kazuki Hayashi
- Department of General Thoracic Surgery, Omi Medical Center, Kusatsu, Japan
| | - Takuya Shiratori
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Japan
| | - Keigo Okamoto
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Japan
| | - Yoko Kataoka
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Japan
| | - Yo Kawaguchi
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Japan
| | - Yasuhiko Ohshio
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Japan
| | - Akinaga Sonoda
- Department of Radiology, Shiga University of Medical Science, Otsu, Japan
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9
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Gaulton TG, Martin K, Xin Y, Victor M, Ribeiro De Santis Santiago R, Britto Passos Amato M, Berra L, Cereda M. Regional lung perfusion using different indicators in electrical impedance tomography. J Appl Physiol (1985) 2023; 135:500-507. [PMID: 37439236 PMCID: PMC10538981 DOI: 10.1152/japplphysiol.00130.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/19/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023] Open
Abstract
Management of acute respiratory distress syndrome (ARDS) is classically guided by protecting the injured lung and mitigating damage from mechanical ventilation. Yet the natural history of ARDS is also dictated by disruption in lung perfusion. Unfortunately, diagnosis and treatment are hampered by the lack of bedside perfusion monitoring. Electrical impedance tomography is a portable imaging technique that can estimate regional lung perfusion in experimental settings from the kinetic analysis of a bolus of an indicator with high conductivity. Hypertonic sodium chloride has been the standard indicator. However, hypertonic sodium chloride is often inaccessible in the hospital, limiting practical adoption. We investigated whether regional lung perfusion measured using electrical impedance tomography is comparable between indicators. Using a swine lung injury model, we determined regional lung perfusion (% of total perfusion) in five pigs, comparing 12% sodium chloride to 8.4% sodium bicarbonate across stages of lung injury and experimental conditions (body position, positive end-expiratory pressure). Regional lung perfusion for four lung regions was determined from maximum slope analysis of the indicator-based impedance signal. Estimates of regional lung perfusion between indicators were compared in the lung overall and within four lung regions. Regional lung perfusion estimated with a sodium bicarbonate indicator agreed with a hypertonic sodium chloride indicator overall (mean bias 0%, limits of agreement -8.43%, 8.43%) and within lung quadrants. The difference in regional lung perfusion between indicators did not change across experimental conditions. Sodium bicarbonate may be a comparable indicator to estimate regional lung perfusion using electrical impedance tomography.NEW & NOTEWORTHY Electrical impedance tomography is an emerging tool to measure regional lung perfusion using kinetic analysis of a conductive indicator. Hypertonic sodium chloride is the standard agent used. We measured regional lung perfusion using another indicator, comparing hypertonic sodium chloride to sodium bicarbonate in an experimental swine lung injury model. We found strong agreement between the two indicators. Sodium bicarbonate may be a comparable indicator to measure regional lung perfusion with electrical impedance tomography.
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Affiliation(s)
- Timothy G Gaulton
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kevin Martin
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Yi Xin
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Marcus Victor
- Pulmonary Division, Heart Institute (InCor), University of São Paulo, São Paulo, Brazil
- Medical Electrical Devices Laboratory (LabMed), Electronics Engineering, Aeronautics Institute of Technology, Sao Jose dos Campos, Brazil
| | - Roberta Ribeiro De Santis Santiago
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | | | - Lorenzo Berra
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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10
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Baranova T, Podyacheva E, Zemlyanukhina T, Berlov D, Danilova M, Glotov O, Glotov A. Vascular Reactions of the Diving Reflex in Men and Women Carrying Different ADRA1A Genotypes. Int J Mol Sci 2022; 23:ijms23169433. [PMID: 36012699 PMCID: PMC9409260 DOI: 10.3390/ijms23169433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 11/29/2022] Open
Abstract
The diving reflex is an oxygen-saving mechanism which is accompanied by apnea, reflex bradycardia development, peripheral vasoconstriction, spleen erythrocyte release, and selective redistribution of blood flow to the organs most vulnerable to lack of oxygen, such as the brain, heart, and lungs. However, this is a poorly studied form of hypoxia, with a knowledge gap on physiological and biochemical adaptation mechanisms. The reflective sympathetic constriction of the resistive vessels is realized via ADRA1A. It has been shown that ADRA1A SNP (p.Arg347Cys; rs1048101) is associated with changes in tonus in vessel walls. Moreover, the Cys347 allele has been shown to regulate systolic blood pressure. The aim of this work was to evaluate whether the ADRA1A polymorphism affected the pulmonary vascular reactions in men and women in response to the diving reflex. Men (n = 52) and women (n = 50) untrained in diving aged 18 to 25 were recruited into the study. The vascular reactions and blood flow were examined by integrated rheography and rheography of the pulmonary artery. Peripheral blood circulation was registered by plethysmography. The ADRA1A gene polymorphism (p.Arg347Cys; rs1048101) was determined by PCR-RFLP. In both men and women, reflective pulmonary vasodilation did occur in response to the diving reflex, but in women this vasodilation was more pronounced and was accompanied by a higher filling of the lungs with blood.. Additionally, ADRA1A SNP (p.Arg347Cys; rs1048101) is associated with sex. Interestingly, women with the Arg347 allele demonstrated the highest vasodilation of the lung vessels. Therefore, our data may help to indicate women with the most prominent adaptive reactions to the diving reflex. Our data also indicate that women and men with the Cys allele of the ADRA1A gene polymorphism have the highest risk of developing lung hypertension in response to the diving reflex. The diving reflex is an oxygen-saving mechanism which is accompanied by apnea, reflex bradycardia development, peripheral vasoconstriction, spleen erythrocyte release, and selective redistribution of blood flow to the organs most vulnerable to lack of oxygen, such as the brain, heart, and lungs. However, this is a poorly studied form of hypoxia, with a knowledge gap on physiological and biochemical adaptation mechanisms.
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Affiliation(s)
- Tatyana Baranova
- Faculty of Biology, Saint Petersburg State University, 199034 Saint-Petersburg, Russia
- Correspondence: ; Tel.: +7-921-331-6581
| | - Ekaterina Podyacheva
- Faculty of Biology, Saint Petersburg State University, 199034 Saint-Petersburg, Russia
| | - Tatyana Zemlyanukhina
- Faculty of Biology, Saint Petersburg State University, 199034 Saint-Petersburg, Russia
| | - Dmitrii Berlov
- Faculty of Biology, Herzen State Pedagogical University of Russia, 191186 Saint-Petersburg, Russia
| | - Maria Danilova
- Department of Genomic Medicine, D.O. Ott’s Institute of Obstetrics, Gynecology and Reproductology, 199034 Saint-Petersburg, Russia
| | - Oleg Glotov
- Department of Genomic Medicine, D.O. Ott’s Institute of Obstetrics, Gynecology and Reproductology, 199034 Saint-Petersburg, Russia
- Department of Experimental Medical Virology, Molecular Genetics and Biobanking of Pediatric Research and Clinical Center for Infectious Diseases, 197022 Saint-Petersburg, Russia
| | - Andrey Glotov
- Department of Genomic Medicine, D.O. Ott’s Institute of Obstetrics, Gynecology and Reproductology, 199034 Saint-Petersburg, Russia
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11
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Prabhu S, Keshav M, Ramachandra P, Raj V, John C, Karl TR. Tetralogy of Fallot with pulmonary atresia and aortopulmonary window may mimic common arterial trunk. Cardiol Young 2022; 32:410-4. [PMID: 34134806 DOI: 10.1017/S1047951121002298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Tetralogy of Fallot with pulmonary atresia is a group of congenital cardiac malformations, which is defined by the absence of luminal continuity between both ventricles and the pulmonary artery, and an interventricular communication. Pulmonary arterial supply in patients with tetralogy of Fallot with pulmonary atresia can be via the arterial duct or from collateral arteries arising directly or indirectly from the aorta (systemic-to-pulmonary artery collaterals), or rarely both. The rarest sources of pulmonary blood flow are aortopulmonary window and fistulous communication with the coronary artery.Herein, we describe an outflow tract malformation, tetralogy of Fallot with pulmonary atresia and aortopulmonary window, which was misdiagnosed as common arterial trunk. We emphasise the morphological differences.
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12
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Ren J, Darby JRT, Lock MC, Holman SL, Saini BS, Bradshaw EL, Orgeig S, Perumal SR, Wiese MD, Macgowan CK, Seed M, Morrison JL. Impact of maternal late gestation undernutrition on surfactant maturation, pulmonary blood flow and oxygen delivery measured by magnetic resonance imaging in the sheep fetus. J Physiol 2021; 599:4705-4724. [PMID: 34487347 DOI: 10.1113/jp281292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 09/01/2021] [Indexed: 11/08/2022] Open
Abstract
Restriction of fetal substrate supply has an adverse effect on surfactant maturation in the lung and thus affects the transition from in utero placental oxygenation to pulmonary ventilation ex utero. The effects on surfactant maturation are mediated by alteration in mechanisms regulating surfactant protein and phospholipid synthesis. This study aimed to determine the effects of late gestation maternal undernutrition (LGUN) and LGUN plus fetal glucose infusion (LGUN+G) compared to Control on surfactant maturation and lung development, and the relationship with pulmonary blood flow and oxygen delivery ( D O 2 ) measured by magnetic resonance imaging (MRI) with molecules that regulate lung development. LGUN from 115 to 140 days' gestation significantly decreased fetal body weight, which was normalized by glucose infusion. LGUN and LGUN+G resulted in decreased fetal plasma glucose concentration, with no change in fetal arterial P O 2 compared to control. There was no effect of LGUN and LGUN+G on the mRNA expression of surfactant proteins (SFTP) and genes regulating surfactant maturation in the fetal lung. However, blood flow in the main pulmonary artery was significantly increased in LGUN, despite no change in blood flow in the left or right pulmonary artery and D O 2 to the fetal lung. There was a negative relationship between left pulmonary artery flow and D O 2 to the left lung with SFTP-B and GLUT1 mRNA expression, while their relationship with VEGFR2 was positive. These results suggest that increased pulmonary blood flow measured by MRI may have an adverse effect on surfactant maturation during fetal lung development. KEY POINTS: Maternal undernutrition during gestation alters fetal lung development by impacting surfactant maturation. However, the direction of change remains controversial. We examined the effects of maternal late gestation maternal undernutrition (LGUN) on maternal and fetal outcomes, signalling pathways involved in fetal lung development, pulmonary haemodynamics and oxygen delivery in sheep using a combination of molecular and magnetic resonance imaging (MRI) techniques. LGUN decreased fetal plasma glucose concentration without affecting arterial P O 2 . Surfactant maturation was not affected; however, main pulmonary artery blood flow was significantly increased in the LGUN fetuses. This is the first study to explore the relationship between in utero MRI measures of pulmonary haemodynamics and lung development. Across all treatment groups, left pulmonary artery blood flow and oxygen delivery were negatively correlated with surfactant protein B mRNA and protein expression in late gestation.
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Affiliation(s)
- Jiaqi Ren
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sandra Orgeig
- UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sunthara R Perumal
- Preclinical Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Michael D Wiese
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | - Mike Seed
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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13
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Lesneski AL, Vali P, Hardie ME, Lakshminrusimha S, Sankaran D. Randomized Trial of Oxygen Saturation Targets during and after Resuscitation and Reversal of Ductal Flow in an Ovine Model of Meconium Aspiration and Pulmonary Hypertension. Children (Basel) 2021; 8:594. [PMID: 34356574 DOI: 10.3390/children8070594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 11/16/2022]
Abstract
Neonatal resuscitation (NRP) guidelines suggest targeting 85-95% preductal SpO2 by 10 min after birth. Optimal oxygen saturation (SpO2) targets during resuscitation and in the post-resuscitation management of neonatal meconium aspiration syndrome (MAS) with persistent pulmonary hypertension (PPHN) remains uncertain. Our objective was to compare the time to reversal of ductal flow from fetal pattern (right-to-left), to left-to-right, and to evaluate pulmonary (QPA), carotid (QCA)and ductal (QDA) blood flows between standard (85-94%) and high (95-99%) SpO2 targets during and after resuscitation. Twelve lambs asphyxiated by endotracheal meconium instillation and cord occlusion to induce MAS and PPHN were resuscitated per NRP guidelines and were randomized to either standard (85-94%) or high (95-99%) SpO2 targets. Out of twelve lambs with MAS and PPHN, six each were randomized to standard and high SpO2 targets. Median [interquartile range] time to change in direction of blood flow across the ductus arteriosus from right-to-left, to left-to-right was significantly shorter with high SpO2 target (7.4 (4.4-10.8) min) compared to standard SpO2 target (31.5 (21-66.2) min, p = 0.03). QPA was significantly higher during the first 10 min after birth with higher SpO2 target. At 60 min after birth, the QPA, QCA and QDA were not different between the groups. To conclude, targeting SpO2 of 95-99% during and after resuscitation may hasten reversal of ductal flow in lambs with MAS and PPHN and transiently increase QPA but no differences were observed at 60 min. Clinical studies comparing low and high SpO2 targets assessing hemodynamics and neurodevelopmental outcomes are warranted.
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14
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Wiezell E, F. Gudnason J, Synnergren M, Sunnegårdh J. Outcome after surgery for pulmonary atresia with ventricular septal defect, a long-term follow-up study. Acta Paediatr 2021; 110:1610-1619. [PMID: 33351279 PMCID: PMC8248001 DOI: 10.1111/apa.15732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/08/2020] [Accepted: 12/21/2020] [Indexed: 11/29/2022]
Abstract
Aim To study the long‐term outcome after surgery for pulmonary atresia and ventricular septal defect (PA‐VSD), and to determine association between the contribution of major aorto‐pulmonary collateral arteries (MAPCAs) to the pulmonary blood flow, comorbidity and cause of death. Methods Patients who had undergone surgery for PA‐VSD from January 1st 1994 to December 31st 2017 were studied retrospectively. Survival was cross‐checked against the Swedish National Population Register. Results Seventy patients were identified, giving an incidence of 5.3 newborns per 100 000 live births. In 41 patients (59%) the pulmonary blood flow originated from a patent ductus arteriosus (PDA), while 29 patients (41%) had contribution of the pulmonary blood flow from MAPCAs. Extracardiac disease was found in 34 patients (49%), 16 of whom had 22q11‐microdeletion syndrome (23%). Survival at follow‐up was similar in patients with and without MAPCAs (72.4% vs. 75.6%, n.s.), with a median follow‐up time of 14.3 years (3.2–41.8 years). No difference was found in mortality in patients with or without any syndrome or extracardiac disease. Conclusion Long‐term survival did not differ between those with and without MAPCAs and no difference in mortality was seen in patients with and without concomitant extracardiac disease or any kind of syndrome.
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Affiliation(s)
- Erik Wiezell
- Department of Paediatrics Södra Älvsborg Hospital Borås Sweden
| | - Janus F. Gudnason
- Children's Heart Center The Queen Silvia Children's Hospital Sahlgrenska University Hospital Gothenburg Sweden
| | - Mats Synnergren
- Children's Heart Center The Queen Silvia Children's Hospital Sahlgrenska University Hospital Gothenburg Sweden
| | - Jan Sunnegårdh
- Children's Heart Center The Queen Silvia Children's Hospital Sahlgrenska University Hospital Gothenburg Sweden
- Institute of Clinical Sciences Gothenburg University Gothenburg Sweden
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15
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Nair J, Davidson L, Gugino S, Koenigsknecht C, Helman J, Nielsen L, Sankaran D, Agrawal V, Chandrasekharan P, Rawat M, Berkelhamer SK, Lakshminrusimha S. Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord. Children (Basel) 2021; 8:children8050353. [PMID: 33946658 PMCID: PMC8145980 DOI: 10.3390/children8050353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022]
Abstract
The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation-SI vs. positive pressure ventilation-V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC-immediate, DCC-60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2-3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.
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Affiliation(s)
- Jayasree Nair
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
- Correspondence: ; Tel.: +1-7163-230-260
| | - Lauren Davidson
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
- Buffalo Neonatology Associates, Sisters of Charity Hospital, Buffalo, NY 14214, USA
| | - Sylvia Gugino
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
| | - Carmon Koenigsknecht
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
| | - Justin Helman
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
| | - Lori Nielsen
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
| | - Deepika Sankaran
- Department of Pediatrics, University of California at Davis, Davis, CA 95616, USA; (D.S.); (S.L.)
| | - Vikash Agrawal
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
- Department of Pediatrics, Loma Linda University, Loma Linda, CA 92350, USA
| | - Praveen Chandrasekharan
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
| | - Munmun Rawat
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
| | - Sara K. Berkelhamer
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14203, USA; (L.D.); (S.G.); (C.K.); (J.H.); (L.N.); (V.A.); (P.C.); (M.R.); (S.K.B.)
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Satyan Lakshminrusimha
- Department of Pediatrics, University of California at Davis, Davis, CA 95616, USA; (D.S.); (S.L.)
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Seith F, Pohmann R, Schwartz M, Küstner T, Othman AE, Kolb M, Scheffler K, Nikolaou K, Schick F, Martirosian P. Imaging Pulmonary Blood Flow Using Pseudocontinuous Arterial Spin Labeling (PCASL) With Balanced Steady-State Free-Precession (bSSFP) Readout at 1.5T. J Magn Reson Imaging 2020; 52:1767-1782. [PMID: 32627293 DOI: 10.1002/jmri.27276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 06/13/2020] [Accepted: 06/15/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Quantitative assessment of pulmonary blood flow and visualization of its temporal and spatial distribution without contrast media is of clinical significance. PURPOSE To assess the potential of electrocardiogram (ECG)-triggered pseudocontinuous arterial spin labeling (PCASL) imaging with balanced steady-state free-precession (bSSFP) readout to measure lung perfusion under free-breathing (FB) conditions and to study temporal and spatial characteristics of pulmonary blood flow. STUDY TYPE Prospective, observational. SUBJECTS Fourteen volunteers; three patients with pulmonary embolism. FIELD STRENGTH/SEQUENCES 1.5T, PCASL-bSSFP. ASSESSMENT The pulmonary trunk was labeled during systole. The following examinations were performed: 1) FB and timed breath-hold (TBH) examinations with a postlabeling delay (PLD) of 1000 msec, and 2) TBH examinations with multiple PLDs (100-1500 msec). Scan-rescan measurements were performed in four volunteers and one patient. Images were registered and the perfusion was evaluated in large vessels, small vessels, and parenchyma. Mean structural similarity indices (MSSIM) was computed and time-to-peak (TTP) of parenchymal perfusion in multiple PLDs was evaluated. Image quality reading was performed with three independent blinded readers. STATISTICAL TESTS Wilcoxon test to compare MSSIM, perfusion, and Likert scores. Spearman's correlation to correlate TTP and cardiac cycle duration. The repeatability coefficient (RC) and within-subject coefficient of variation (wCV) for scan-rescan measurements. Intraclass correlation coefficient (ICC) for interreader agreement. RESULTS Image registration resulted in a significant (P < 0.05) increase of MSSIM. FB perfusion values were 6% higher than TBH (3.28 ± 1.09 vs. 3.10 ± 0.99 mL/min/mL). TTP was highly correlated with individuals' cardiac cycle duration (Spearman = 0.89, P < 0.001). RC and wCV were better for TBH than FB (0.13-0.19 vs. 0.47-1.54 mL/min/mL; 6-7 vs. 19-60%). Image quality was rated very good, with ICCs 0.71-0.89. DATA CONCLUSION ECG-triggered PCASL-bSSFP imaging of the lung at 1.5T can provide very good image quality and quantitative perfusion maps even under FB. The course of labeled blood through the lung shows a strong dependence on the individuals' cardiac cycle duration. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY STAGE: 2 J. MAGN. RESON. IMAGING 2020;52:1767-1782.
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Affiliation(s)
- Ferdinand Seith
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Rolf Pohmann
- High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
| | - Martin Schwartz
- Section on Experimental Radiology, Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.,Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany
| | - Thomas Küstner
- Section on Experimental Radiology, Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.,Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany
| | - Ahmed E Othman
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Manuel Kolb
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Klaus Scheffler
- High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany.,Department for Biomedical Magnetic Resonance, University of Tuebingen, Tuebingen, Germany
| | - Konstantin Nikolaou
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Fritz Schick
- Section on Experimental Radiology, Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Petros Martirosian
- Section on Experimental Radiology, Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
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17
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Himstedt A, Braun C, Wicha SG, Borghardt JM. Towards a Quantitative Mechanistic Understanding of Localized Pulmonary Tissue Retention-A Combined In Vivo/In Silico Approach Based on Four Model Drugs. Pharmaceutics 2020; 12:E408. [PMID: 32365674 PMCID: PMC7284631 DOI: 10.3390/pharmaceutics12050408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/23/2020] [Accepted: 04/27/2020] [Indexed: 01/25/2023] Open
Abstract
Increasing affinity to lung tissue is an important strategy to achieve pulmonary retention and to prolong the duration of effect in the lung. As the lung is a very heterogeneous organ, differences in structure and blood flow may influence local pulmonary disposition. Here, a novel lung preparation technique was employed to investigate regional lung distribution of four drugs (salmeterol, fluticasone propionate, linezolid, and indomethacin) after intravenous administration in rats. A semi-mechanistic model was used to describe the observed drug concentrations in the trachea, bronchi, and the alveolar parenchyma based on tissue specific affinities (Kp) and blood flows. The model-based analysis was able to explain the pulmonary pharmacokinetics (PK) of the two neutral and one basic model drugs, suggesting up to six-fold differences in Kp between trachea and alveolar parenchyma for salmeterol. Applying the same principles, it was not possible to predict the pulmonary PK of indomethacin, indicating that acidic drugs might show different pulmonary PK characteristics. The separate estimates for local Kp, tracheal and bronchial blood flow were reported for the first time. This work highlights the importance of lung physiology- and drug-specific parameters for regional pulmonary tissue retention. Its understanding is key to optimize inhaled drugs for lung diseases.
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Affiliation(s)
- Anneke Himstedt
- Department of Clinical Pharmacy, Institute of Pharmacy, University of Hamburg, 20146 Hamburg, Germany;
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, 88397 Biberach, Germany;
| | - Clemens Braun
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, 88397 Biberach, Germany;
| | - Sebastian Georg Wicha
- Department of Clinical Pharmacy, Institute of Pharmacy, University of Hamburg, 20146 Hamburg, Germany;
| | - Jens Markus Borghardt
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, 88397 Biberach, Germany;
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18
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Martherus T, Crossley KJ, Rodgers KA, Dekker J, Demel A, Moxham AM, Zahra VA, Polglase GR, Roberts CT, Te Pas AB, Hooper SB. High-CPAP Does Not Impede Cardiovascular Changes at Birth in Preterm Sheep. Front Pediatr 2020; 8:584138. [PMID: 33553064 PMCID: PMC7862825 DOI: 10.3389/fped.2020.584138] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/22/2020] [Indexed: 12/04/2022] Open
Abstract
Objective: Continuous positive airway pressures (CPAP) used to assist preterm infants at birth are limited to 4-8 cmH2O due to concerns that high-CPAP may cause pulmonary overexpansion and adversely affect the cardiovascular system. We investigated the effects of high-CPAP on pulmonary (PBF) and cerebral (CBF) blood flows and jugular vein pressure (JVP) after birth in preterm lambs. Methods: Preterm lambs instrumented with flow probes and catheters were delivered at 133/146 days gestation. Lambs received low-CPAP (LCPAP: 5 cmH2O), high-CPAP (HCPAP: 15 cmH2O) or dynamic HCPAP (15 decreasing to 8 cmH2O at ~2 cmH2O/min) for up to 30 min after birth. Results: Mean PBF was lower in the LCPAP [median (Q1-Q3); 202 (48-277) mL/min, p = 0.002] compared to HCPAP [315 (221-365) mL/min] and dynamic HCPAP [327 (269-376) mL/min] lambs. CBF was similar in LCPAP [65 (37-78) mL/min], HCPAP [73 (41-106) mL/min], and dynamic HCPAP [66 (52-81) mL/min, p = 0.174] lambs. JVP was similar at CPAPs of 5 [8.0 (5.1-12.4) mmHg], 8 [9.4 (5.3-13.4) mmHg], and 15 cmH2O [8.6 (6.9-10.5) mmHg, p = 0.909]. Heart rate was lower in the LCPAP [134 (101-174) bpm; p = 0.028] compared to the HCPAP [173 (139-205)] and dynamic HCPAP [188 (161-207) bpm] groups. Ventilation or additional caffeine was required in 5/6 LCPAP, 1/6 HCPAP, and 5/7 dynamic HCPAP lambs (p = 0.082), whereas 3/6 LCPAP, but no HCPAP lambs required intubation (p = 0.041), and 1/6 LCPAP, but no HCPAP lambs developed a pneumothorax (p = 0.632). Conclusion: High-CPAP did not impede the increase in PBF at birth and supported preterm lambs without affecting CBF and JVP.
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Affiliation(s)
- Tessa Martherus
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Karyn A Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Janneke Dekker
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands.,The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Anja Demel
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Alison M Moxham
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Valerie A Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynecology, Monash University, Melbourne, VIC, Australia
| | - Calum T Roberts
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Monash Newborn, Monash Medical Centre, Melbourne, VIC, Australia
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynecology, Monash University, Melbourne, VIC, Australia
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19
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Stadler S, Mergenthaler N, Lange TJ. The prognostic value of DLCO and pulmonary blood flow in patients with pulmonary hypertension. Pulm Circ 2019; 9:2045894019894531. [PMID: 31908765 PMCID: PMC6935895 DOI: 10.1177/2045894019894531] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022] Open
Abstract
Background Cardiac output is a prognostic marker in patients with pulmonary hypertension. Pulmonary blood flow as a surrogate for cardiac output can be measured non-invasively by inert gas rebreathing. We hypothesized that pulmonary blood flow can predict outcome in patients with pulmonary hypertension. Methods From January 2009 to January 2012, we measured pulmonary blood flow by inert gas rebreathing in outpatients with pulmonary hypertension. Patients with pulmonary hypertension confirmed by right heart catheterization and a valid inert gas rebreathing maneuver were followed until January 2016. The investigated outcome was all-cause mortality. Results We included 259 patients (mean age 65 ± 13 years, 53% female) with pulmonary hypertension and classified into groups 1 (n = 103), 2 (n = 26), 3 (n = 80), and 4 (n = 50) according to the current pulmonary hypertension classification system. The median time between pulmonary hypertension diagnosis and inert gas rebreathing was 9 (IQR 0; 36) months. During a median follow-up time of 51 (IQR 20; 68) months, 109 patients (42%) died. Parameters significantly associated with survival (in order of decreasing statistical strength) were diffusion capacity of the lung for carbon monoxide (DLCO), 6-minute walk distance (6-MWD), age, NTpro-BNP, WHO functional class, group 3 pulmonary hypertension, and tricuspid annular plane systolic excursion (TAPSE), while baseline hemodynamics and pulmonary blood flow were not. In multivariable Cox regression analysis, DLCO, age, 6-MWD, and TAPSE remained significant and independent predictors of the outcome. DLCO as the strongest parameter also significantly predicted survival in aetiological subgroups except for group 4. Conclusions DLCO is a strong and independent predictor for survival in patients with pulmonary hypertension of different aetiologies, while pulmonary blood flow measured by inert gas rebreathing is not.
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Affiliation(s)
- Stefan Stadler
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
| | - Nicoletta Mergenthaler
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
| | - Tobias J Lange
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
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20
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Zhang Y, Escher AR, Cohen JB, Liu J. Anesthetic Management of Right Single-lung Ventilation in a Patient with Anomalous Left Superior Pulmonary Venous Return for Left Pulmonary Lobectomy. Cureus 2019; 11:e5780. [PMID: 31723539 PMCID: PMC6825499 DOI: 10.7759/cureus.5780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Partial anomalous pulmonary venous return (PAPVR) is a rare congenital anomaly in which one or more of the pulmonary veins are connected to the right atrium or to the systemic venous system. One lung ventilation (OLV) is required for a number of thoracic procedures. When switching to OLV, right-to-left shunt fraction increases, oxygenation is impaired, and hypoxemia may occur. Hypoxemia during OLV may affect the safety of the patient and is a challenge for the anesthesiologist and the surgeon. This case details the intraoperative anesthetic management of an elderly patient with a PAPVR who underwent single-lung ventilation for lung resection surgery.
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Affiliation(s)
- Yu Zhang
- Anesthesiology, Tianjin Cancer Hospital, Tianjin, CHN
| | - Allan R Escher
- Anesthesiology / Pain Medicine, H. Lee Moffitt Cancer Center and Research Institute, Tampa, USA
| | - Jonathan B Cohen
- Anesthesiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, USA
| | - Jinhong Liu
- Anesthesiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, USA
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21
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Addo DA, Kang W, Prisk GK, Tawhai MH, Burrowes KS. Optimizing human pulmonary perfusion measurement using an in silico model of arterial spin labeling magnetic resonance imaging. Physiol Rep 2019; 7:e14077. [PMID: 31197965 PMCID: PMC6565801 DOI: 10.14814/phy2.14077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/17/2019] [Accepted: 04/02/2019] [Indexed: 11/28/2022] Open
Abstract
Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is an imaging methodology that uses blood as an endogenous contrast agent to quantify flow. One limitation of this method of capillary blood quantification when applied in the lung is the contribution of signals from non-capillary blood. Intensity thresholding is one approach that has been proposed for minimizing the non-capillary blood signal. This method has been tested in previous in silico modeling studies; however, it has only been tested under a restricted set of physiological conditions (supine posture and a cardiac output of 5 L/min). This study presents an in silico approach that extends previous intensity thresholding analysis to estimate the optimal "per-slice" intensity threshold value using the individual components of the simulated ASL signal (signal arising independently from capillary blood as well as pulmonary arterial and pulmonary venous blood). The aim of this study was to assess whether the threshold value should vary with slice location, posture, or cardiac output. We applied an in silico modeling approach to predict the blood flow distribution and the corresponding ASL quantification of pulmonary perfusion in multiple sagittal imaging slices. There was a significant increase in ASL signal and heterogeneity (COV = 0.90 to COV = 1.65) of ASL signals when slice location changed from lateral to medial. Heterogeneity of the ASL signal within a slice was significantly lower (P = 0.03) in prone (COV = 1.08) compared to in the supine posture (COV = 1.17). Increasing stroke volume resulted in an increase in ASL signal and conversely an increase in heart rate resulted in a decrease in ASL signal. However, when cardiac output was increased via an increase in both stroke volume and heart rate, ASL signal remained relatively constant. Despite these differences, we conclude that a threshold value of 35% provides optimal removal of large vessel signal independent of slice location, posture, and cardiac output.
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Affiliation(s)
- Daniel A. Addo
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Wendy Kang
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Gordon Kim Prisk
- Departments of Medicine and RadiologyUniversity of CaliforniaSan DiegoLa JollaCalifornia
| | - Merryn H. Tawhai
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Kelly Suzzane Burrowes
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
- Department of Chemical and Materials EngineeringUniversity of AucklandAucklandNew Zealand
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22
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Karlsson J, Wallin M, Hallbäck M, Lönnqvist PA. Capnodynamic determination of cardiac output in hypoxia-induced pulmonary hypertension in pigs. Br J Anaesth 2018; 122:335-341. [PMID: 30770051 DOI: 10.1016/j.bja.2018.10.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Effective pulmonary blood flow (COEPBF) has recently been validated for its ability to measure cardiac output (CO) in children and animals. This study compared COEPBF with the Fick method (COFick) and CO measurements using an invasive pulmonary artery flow probe (COTS). The aim of the study was to validate COEPBF against these reference methods in a porcine model of hypoxia-induced selective pulmonary hypertension. METHODS Ten anaesthetised mechanically ventilated piglets (median weight 23.9 kg) were exposed to a hypoxic gas mixture inducing selective pulmonary hypertension. Pulmonary hypertension was subsequently reversed with inhaled nitric oxide. Simultaneous recordings of COEPBF, COFick, and COTS were performed throughout the protocol and examined for agreement and trending ability. RESULTS Overall bias (Bland-Altman) between COEPBF and COTS was 0.2 L min-1 (limits of agreement -0.5 and +0.9 L min-1) with a mean percentage error of 25%. Overall bias between COEPBF and COFick was -0.1 L min-1 (limits of agreement -0.9 and +0.6 L min-1) and a mean percentage error of 25%. The concordance rate was 86% for COEPBF when compared with COTS using a 10% exclusion zone. CONCLUSIONS Estimation of CO with COEPBF results in values very close to the gold standard reference methods COFick and COTS. COEPBF appears to be an accurate tool for monitoring absolute values and changes in CO during hypoxia-induced pulmonary hypertension and inhaled nitric oxide treatment.
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Affiliation(s)
- J Karlsson
- Department of Physiology and Pharmacology (FYFA), C3, Eriksson I Lars Group, Section of Anesthesiology and Intensive Care, Karolinska Institute, Stockholm, Sweden; Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.
| | - M Wallin
- Department of Physiology and Pharmacology (FYFA), C3, Eriksson I Lars Group, Section of Anesthesiology and Intensive Care, Karolinska Institute, Stockholm, Sweden; Maquet Critical Care AB, Solna, Sweden
| | | | - P A Lönnqvist
- Department of Physiology and Pharmacology (FYFA), C3, Eriksson I Lars Group, Section of Anesthesiology and Intensive Care, Karolinska Institute, Stockholm, Sweden; Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
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23
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Al-Subu A, Jooste E, Hornik CP, Fleming GA, Cheifetz IM, Ofori-Amanfo G. Correlation between minute carbon dioxide elimination and pulmonary blood flow in single-ventricle patients after stage 1 palliation and 2-ventricle patients with intracardiac shunts: A pilot study. Paediatr Anaesth 2018; 28:618-624. [PMID: 30133920 PMCID: PMC6485938 DOI: 10.1111/pan.13423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/19/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND Assessment of pulmonary blood flow and cardiac output is critical in the postoperative management of patients with single-ventricle physiology or 2-ventricle physiology with intracardiac shunting. Currently, such hemodynamic data are only obtainable by invasive procedures, such as cardiac catheterization or the use of a pulmonary artery catheter. Ready availability of such information, especially if attainable noninvasively, could be a valuable addition to postoperative management. AIMS The aim of this study was to assess the correlation between volume of CO2 elimination obtained by volumetric capnography and pulmonary blood flow in pediatric patients with single-ventricle physiology after stage 1 palliation as well as in patients with other cardiac lesions associated with intracardiac shunting. METHODS This prospective cohort study included children with congenital or acquired heart disease who underwent cardiac catheterization as part of clinical care. Cardiac output, pulmonary blood flow, and volume of CO2 elimination were simultaneously collected. Spearman's rank correlation coefficients were used to assess correlation between measurements after controlling for minute ventilation. RESULTS Thirty-five patients were enrolled and divided into 3 groups. Group 1 (n = 8) included single-ventricle patients after stage 1 palliation. Group 2 (n = 10) patients had structural heart disease with 2 ventricles and intracardiac shunting. Group 3 (n = 17) had structurally normal hearts. Among Group 1 patients, the correlation coefficients (R2 ) between volume of CO2 elimination and pulmonary blood flow and volume of CO2 elimination and cardiac output were 0.60 (P = .02) 95% CI [0.01-0.79] and 0.29 (P = .74) 95% CI [-0.91 - 0.86], respectively. In patients with 2 ventricles associated with intracardiac shunts (Group 2), the correlation coefficients between volume of CO2 elimination and pulmonary blood flow and volume of CO2 elimination and cardiac output were 0.86 (P = .001) 95% CI [0.53 - 0.97] and 0.73 (P = .001) 95% CI [0.29 - 0.95], respectively. Among Group 3 patients, the correlation coefficient between volume of CO2 elimination and pulmonary blood flow was 0.66 (P = .038) 95% CI [0.29 - 0.87]. CONCLUSION Volume of CO2 elimination may be a surrogate marker of pulmonary blood flow in single-ventricle patients and patients with biventricular physiology with intracardiac shunting. Also, among patients with normal cardiac anatomy, volume of CO2 elimination may be a marker of cardiac output.
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Affiliation(s)
- Awni Al-Subu
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Edmund Jooste
- Division of Pediatric Anesthesiology, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Christoph P. Hornik
- Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA,Duke Clinical Research Institute, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Gregory A. Fleming
- Division of Pediatric Cardiology, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Ira M. Cheifetz
- Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - George Ofori-Amanfo
- Division of Pediatric Critical Care, Department of Pediatrics, Kravis Children’s Hospital at Mount Sinai, New York, NY, USA
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24
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Gramatté J, Pietzsch J, Bergmann R, Richter T. Causative treatment of acid aspiration induced acute lung injury - Recent trends from animal experiments and critical perspective. Clin Hemorheol Microcirc 2018; 69:187-195. [PMID: 29630538 DOI: 10.3233/ch-189113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aspiration of low-pH gastric fluid leads to an initial pneumonitis, which may become complicated by subsequent pneumonia or acute respiratory distress syndrome. Current treatment is at best supportive, but there is growing experimental evidence on the significant contribution of both neutrophils and platelets in the development of this inflammatory pulmonary reaction, a condition that can be attenuated by several medicinal products. This review aims to summarize novel findings in experimental models on pathomechanisms after an acid-aspiration event. Given the clinical relevance, specific emphasis is put on deduced potential experimental therapeutic approaches, which make use of the characteristic alteration of microcirculation in the injured lung.
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Affiliation(s)
- Johannes Gramatté
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
| | - Jens Pietzsch
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Ralf Bergmann
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Torsten Richter
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
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25
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Matheson PJ, Eid MA, Wilson MA, Graham VS, Matheson SA, Weaver JL, Downard CD, Smith JW. Damage-associated molecular patterns in resuscitated hemorrhagic shock are mitigated by peritoneal fluid administration. Am J Physiol Lung Cell Mol Physiol 2018; 315:L339-L347. [PMID: 29722563 DOI: 10.1152/ajplung.00183.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Conventional resuscitation (CR) of hemorrhagic shock (HS), a significant cause of trauma mortality, is intravenous blood and fluids. CR restores central hemodynamics, but vital organ flow can drop, causing hypoperfusion, hypoxia, damage-associated molecular patterns (DAMPs), and remote organ dysfunction (i.e., lung). CR plus direct peritoneal resuscitation (DPR) prevents intestinal and hepatic hypoperfusion. We hypothesized that DPR prevents lung injury in HS/CR by altering DAMPs. Anesthetized male Sprague-Dawley rats were randomized to groups ( n = 8/group) in one of two sets: 1) sham (no HS, CR, or DPR), 2) HS/CR (HS = 40% mean arterial pressure (MAP) for 60 min, CR = shed blood + 2 volumes normal saline), or 3) HS/CR + DPR. The first set underwent whole lung blood flow by colorimetric microspheres. The second set underwent tissue collection for Luminex, ELISAs, and histopathology. Lipopolysaccharide (LPS) and DAMPs were measured in serum and/or lung, including cytokines, hyaluronic acid (HA), high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 protein (MYD88), and TIR-domain-containing adapter-inducing interferon-β (TRIF). Statistics were by ANOVA and Tukey-Kramer test with a priori P < 0.05. HS/CR increased serum LPS, HA, HMGB1, and some cytokines [interleukin (IL)-1α, IL-1β, IL-6, and interferon-γ]. Lung TLR4 and MYD88 were increased but not TRIF compared with Shams. HS/CR + DPR decreased LPS, HA, cytokines, HMGB1, TLR4, and MYD88 levels but did not alter TRIF compared with HS/CR. The data suggest that gut-derived DAMPs can be modulated by adjunctive DPR to prevent activation of lung TLR-4-mediated processes. Also, DPR improved lung blood flow and reduced lung tissue injury. Adjunctive DPR in HS/CR potentially improves morbidity and mortality by downregulating the systemic DAMP response.
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Affiliation(s)
- Paul J Matheson
- Robley Rex Veterans Affairs Medical Center , Louisville, Kentucky.,Department of Surgery, University of Louisville , Louisville, Kentucky.,Department of Physiology and Biophysics, University of Louisville , Louisville, Kentucky
| | - Mark A Eid
- Department of Surgery, University of Louisville , Louisville, Kentucky
| | - Matthew A Wilson
- Department of Surgery, University of Louisville , Louisville, Kentucky
| | - Victoria S Graham
- Department of Surgery, University of Louisville , Louisville, Kentucky
| | - Samuel A Matheson
- Department of Surgery, University of Louisville , Louisville, Kentucky
| | - Jessica L Weaver
- Department of Surgery, University of Louisville , Louisville, Kentucky.,Department of Physiology and Biophysics, University of Louisville , Louisville, Kentucky
| | - Cynthia D Downard
- Robley Rex Veterans Affairs Medical Center , Louisville, Kentucky.,Department of Surgery, University of Louisville , Louisville, Kentucky
| | - Jason W Smith
- Robley Rex Veterans Affairs Medical Center , Louisville, Kentucky.,Department of Surgery, University of Louisville , Louisville, Kentucky.,Department of Physiology and Biophysics, University of Louisville , Louisville, Kentucky
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26
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Black SM, Field-Ridley A, Sharma S, Kumar S, Keller RL, Kameny R, Maltepe E, Datar SA, Fineman JR. Altered Carnitine Homeostasis in Children With Increased Pulmonary Blood Flow Due to Ventricular Septal Defects. Pediatr Crit Care Med 2017; 18:931-4. [PMID: 28723882 DOI: 10.1097/PCC.0000000000001275] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVES Congenital heart disease with increased pulmonary blood flow results in progressive pulmonary vascular endothelial dysfunction and associated increased perioperative morbidity. Using our ovine model of congenital heart disease with increased pulmonary blood flow, we have previously demonstrated progressive endothelial dysfunction associated with disruption in carnitine homeostasis, mitochondrial dysfunction, decreased nitric oxide signaling, and enhanced reactive oxygen species generation. However, potential alterations in these parameters in patients with congenital heart disease have not been investigated. The objective of this study was to test the hypothesis that children with increased pulmonary blood flow will have evidence of altered carnitine homeostasis, mitochondrial dysfunction, decreased nitric oxide levels, and increased reactive oxygen species generation. DESIGN A prospective single-center cohort study. SETTING A tertiary care cardiac ICU/PICU. PATIENTS Arterial blood samples from 18 patients with congenital heart disease associated with increased pulmonary blood flow (ventricular septal defect), 20 with congenital heart disease without increased pulmonary blood flow (tetralogy of Fallot), and 10 without heart disease (controls) were obtained. INTERVENTIONS Plasma levels of total carnitine, free carnitine, acylcarnitine, and lactate-to-pyruvate ratios, an indicator of mitochondrial function, were determined and compared. In addition, levels of superoxide and hydrogen peroxide were determined and compared in patients with ventricular septal defect and controls. Statistical analysis was performed using an unpaired t test and analysis of variance. MEASUREMENTS AND MAIN RESULTS Baseline acylcarnitine levels (25.7 ± 13 vs 12.7 ± 8.3; p < 0.05), the acylcarnitine-to-free carnitine ratio (0.8 ± 0.1 vs 0.3 ± 0.05; p < 0.05), and the lactate-to-pyruvate ratio were higher in ventricular septal defect (27.5 ± 3.8 vs 11.1 ± 4.1, p < 0.05) than tetralogy of Fallot; there were no differences between tetralogy of Fallot and control. Superoxide and H2O2 levels were also higher in ventricular septal defect compared with controls, and NOx levels were lower in ventricular septal defect patients compared with tetralogy of Fallot and controls (p < 0.05). CONCLUSIONS These data suggest that increased pulmonary blood flow from ventricular septal defect results in altered carnitine and mitochondrial homeostasis, decreased nitric oxide signaling, and increased reactive oxygen species production. These data are consistent with our animal data demonstrating that altered carnitine homeostasis results in mitochondrial dysfunction, increased reactive oxygen species production, and decreased bioavailable nitric oxide. Since disruption of carnitine metabolism may contribute to endothelial dysfunction, carnitine supplementation may attenuate endothelial dysfunction associated with increased pulmonary blood flow and warrants further investigation.
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27
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Mathew B, Lakshminrusimha S. Persistent Pulmonary Hypertension in the Newborn. Children (Basel) 2017; 4:children4080063. [PMID: 28788074 PMCID: PMC5575585 DOI: 10.3390/children4080063] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/18/2017] [Accepted: 07/25/2017] [Indexed: 11/16/2022]
Abstract
Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of failed circulatory adaptation at birth due to delay or impairment in the normal fall in pulmonary vascular resistance (PVR) that occurs following birth. The fetus is in a state of physiological pulmonary hypertension. In utero, the fetus receives oxygenated blood from the placenta through the umbilical vein. At birth, following initiation of respiration, there is a sudden precipitous fall in the PVR and an increase of systemic vascular resistance (SVR) due to the removal of the placenta from circulation. There is dramatic increase in pulmonary blood flow with a decrease in, and later reversal of shunts at the foramen ovale and ductus arteriosus. The failure of this normal physiological pulmonary transition leads to the syndrome of PPHN. PPHN presents with varying degrees of hypoxemic respiratory failure. Survival of infants with PPHN has significantly improved with the use of gentle ventilation, surfactant and inhaled nitric oxide (iNO). PPHN is associated with significant mortality and morbidity among survivors. Newer agents that target different enzymatic pathways in the vascular smooth muscle are in different stages of development and testing. Further research using these agents is likely to further reduce morbidity and mortality associated with PPHN.
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Affiliation(s)
- Bobby Mathew
- Department of Pediatrics, University at Buffalo, Buffalo, NY 14222, USA.
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Bates ML, Jacobson JE, Eldridge MW. Beta Adrenergic Regulation of Intrapulmonary Arteriovenous Anastomoses in Intact Rat and Isolated Rat Lungs. Front Physiol 2017; 8:218. [PMID: 28469578 PMCID: PMC5396286 DOI: 10.3389/fphys.2017.00218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/27/2017] [Indexed: 11/18/2022] Open
Abstract
Intrapulmonary arteriovenous anastomoses (IPAVA) allow large diameter particles of venous origin to bypass the pulmonary capillary bed and embolize the systemic arterial circulation. IPAVA have been routinely observed in healthy humans with exercise, hypoxia, and catecholamine infusion, but the mechanism by which they are recruited is not well-defined. We hypothesized that beta-adrenergic receptor stimulation recruits IPAVA and that receptor blockade would limit hypoxia-induced IPAVA recruitment. To test our hypothesis, we evaluated the transpulmonary passage of microspheres in intact rats and isolated rats lung infused with the beta-adrenergic receptor agonist isoproterenol. We also evaluated IPAVA recruitment in intact rats with hypoxia and the beta-adrenergic receptor blocker propranolol. We found that IPAVA are recruited in the intact rat by isoproterenol and their recruitment by hypoxia can be minimized by propranolol, suggesting a role for the adrenergic system in the recruitment of IPAVA by hypoxia. IPAVA recruitment is completely abolished by ventilation with 100% oxygen. Isoproterenol also recruits IPAVA in isolated rat lungs. The fact that isoproterenol can recruit IPAVA in isolated lungs, without increased pulmonary flow, suggests that elevated cardiac output is not required for IPAVA recruitment.
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Affiliation(s)
- Melissa L Bates
- Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, Department of Pediatrics, University of IowaIowa City, IA, USA.,Department of Health and Human Physiology, University of IowaIowa City, IA, USA
| | - Joseph E Jacobson
- Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, Department of Pediatrics, University of IowaIowa City, IA, USA.,Michigan State University College of Human MedicineEast Lansing, MI, USA
| | - Marlowe W Eldridge
- Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, Department of Pediatrics, University of IowaIowa City, IA, USA.,Departments of Biomedical Engineering and Kinesiology, University of WisconsinMadison, WI, USA
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Lang JAR, Pearson JT, Binder-Heschl C, Wallace MJ, Siew ML, Kitchen MJ, Te Pas AB, Lewis RA, Polglase GR, Shirai M, Hooper SB. Vagal denervation inhibits the increase in pulmonary blood flow during partial lung aeration at birth. J Physiol 2017; 595:1593-1606. [PMID: 27902842 DOI: 10.1113/jp273682] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 11/15/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Lung aeration at birth significantly increases pulmonary blood flow, which is unrelated to increased oxygenation or other spatial relationships that match ventilation to perfusion. Using simultaneous X-ray imaging and angiography in near-term rabbits, we investigated the relative contributions of the vagus nerve and oxygenation to the increase in pulmonary blood flow at birth. Vagal denervation inhibited the global increase in pulmonary blood flow induced by partial lung aeration, although high inspired oxygen concentrations can partially mitigate this effect. The results of the present study indicate that a vagal reflex may mediate a rapid global increase in pulmonary blood flow in response to partial lung aeration. ABSTRACT Air entry into the lungs at birth triggers major cardiovascular changes, including a large increase in pulmonary blood flow (PBF) that is not spatially related to regional lung aeration. To investigate the possible underlying role of a vagally-mediated stimulus, we used simultaneous phase-contrast X-ray imaging and angiography in near-term (30 days of gestation) vagotomized (n = 15) or sham-operated (n = 15) rabbit kittens. Rabbits were imaged before ventilation, when one lung was ventilated (unilateral) with 100% nitrogen (N2 ), air or 100% oxygen (O2 ), and after all kittens were switched to unilateral ventilation in air and then ventilation of both lungs using air. Compared to control kittens, vagotomized kittens had little or no increase in PBF in both lungs following unilateral ventilation when ventilation occurred with 100% N2 or with air. However, relative PBF did increase in vagotomized animals ventilated with 100% O2 , indicating the independent stimulatory effects of local oxygen concentration and autonomic innervation on the changes in PBF at birth. These findings demonstrate that vagal denervation inhibits the previously observed increase in PBF with partial lung aeration, although high inspired oxygen concentrations can partially mitigate this effect.
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Affiliation(s)
- Justin A R Lang
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - James T Pearson
- Monash Biomedical Imaging Facility and Department of Physiology, Monash University, Melbourne, Australia.,Australian Synchrotron, Melbourne, Australia.,Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre Research Institute, Osaka, Japan
| | - Corinna Binder-Heschl
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.,Medical University of Graz, Austria
| | - Megan J Wallace
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Melissa L Siew
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Marcus J Kitchen
- School of Physics and Astronomy, Monash University, Melbourne, Australia
| | - Arjan B Te Pas
- Department of Pediatrics, Leiden University Medical Centre, Leiden, Netherlands
| | - Robert A Lewis
- Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia.,Department of Medical Imaging, University of Saskatchewan, Saskatoon, Canada
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre Research Institute, Osaka, Japan
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
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Affiliation(s)
- Noah H Hillman
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, Saint Louis, MO, 63104, USA
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Richter T, Bergmann R, Pietzsch J, Mueller MP, Koch T. Effects of pulmonary acid aspiration on the regional pulmonary blood flow within the first hour after injury: An observational study in rats. Clin Hemorheol Microcirc 2016; 60:253-62. [PMID: 25171591 DOI: 10.3233/ch-141867] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Gastric aspiration events are recognized as a major cause of pneumonitis and the development of acute respiratory distress syndrome. The first peak in the inflammatory response has been observed one hour after acid-induced lung injury in rats. The spatial pulmonary blood flow (PBF) distribution after an acid aspiration event within this time frame has not been adequately studied. We determined therefore PBF pattern within the first hour after acid aspiration. METHODS Anesthetized, spontaneous breathing rats (n = 8) underwent unilateral endobronchial hydrochlorid acid instillation so that the PBF distributions between the injured and non-injured lungs could be compared. The signal intensity of the lung parenchyma after injury was measured by magnetic resonance tomography. PBF distribution was determined by measuring the concentration of [68Ga]-radiolabeled microspheres using positron emission tomography. RESULTS Following acid aspiration, magnetic resonance images revealed increased signal intensity in the injured regions accompanied by reduced oxygenation. PBF was increased in all injured lungs (171 [150; 196], median [25%; 75%]) compared to the blood flow in all uninjured lungs (141 [122; 159], P = 0.0078). CONCLUSIONS From the first minute until fifty minutes after acid-induced acute lung injury, the PBF was consistently increased in the injured lung. These blood flow elevation was accompanied by significant hypoxemia.
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Affiliation(s)
- Torsten Richter
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
| | - Ralf Bergmann
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum, Dresden-Rossendorf, Dresden, Germany
| | - Jens Pietzsch
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum, Dresden-Rossendorf, Dresden, Germany.,Department of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Michael Patrick Mueller
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
| | - Thea Koch
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
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Iyer KS, Newell JD, Jin D, Fuld MK, Saha PK, Hansdottir S, Hoffman EA. Quantitative Dual-Energy Computed Tomography Supports a Vascular Etiology of Smoking-induced Inflammatory Lung Disease. Am J Respir Crit Care Med 2016; 193:652-61. [PMID: 26569033 DOI: 10.1164/rccm.201506-1196oc] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RATIONALE Endothelial dysfunction is of interest in relation to smoking-associated emphysema, a component of chronic obstructive pulmonary disease (COPD). We previously demonstrated that computed tomography (CT)-derived pulmonary blood flow (PBF) heterogeneity is greater in smokers with normal pulmonary function tests (PFTs) but who have visual evidence of centriacinar emphysema (CAE) on CT. OBJECTIVES We introduced dual-energy CT (DECT) perfused blood volume (PBV) as a PBF surrogate to evaluate whether the CAE-associated increased PBF heterogeneity is reversible with sildenafil. METHODS Seventeen PFT-normal current smokers were divided into CAE-susceptible (SS; n = 10) and nonsusceptible (NS; n = 7) smokers, based on the presence or absence of CT-detected CAE. DECT-PBV images were acquired before and 1 hour after administration of 20 mg oral sildenafil. Regional PBV and PBV coefficients of variation (CV), a measure of spatial blood flow heterogeneity, were determined, followed by quantitative assessment of the central arterial tree. MEASUREMENTS AND MAIN RESULTS After sildenafil administration, regional PBV-CV decreased in SS subjects but did not decrease in NS subjects (P < 0.05), after adjusting for age and pack-years. Quantitative evaluation of the central pulmonary arteries revealed higher arterial volume and greater cross-sectional area (CSA) in the lower lobes of SS smokers, which suggested arterial enlargement in response to increased peripheral resistance. After sildenafil, arterial CSA decreased in SS smokers but did not decrease in NS smokers (P < 0.01). CONCLUSIONS These results demonstrate that sildenafil restores peripheral perfusion and reduces central arterial enlargement in normal SS subjects with little effect in NS subjects, highlighting DECT-PBV as a biomarker of reversible endothelial dysfunction in smokers with CAE.
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Affiliation(s)
| | - John D Newell
- 1 Department of Biomedical Engineering.,2 Department of Radiology
| | - Dakai Jin
- 3 Department of Electrical Engineering, and
| | | | - Punam K Saha
- 2 Department of Radiology.,3 Department of Electrical Engineering, and
| | - Sif Hansdottir
- 5 Division of Pulmonary Medicine, Department of Internal Medicine, University of Iowa, Iowa City, Iowa; and
| | - Eric A Hoffman
- 1 Department of Biomedical Engineering.,2 Department of Radiology.,5 Division of Pulmonary Medicine, Department of Internal Medicine, University of Iowa, Iowa City, Iowa; and
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Dane DM, Yilmaz C, Gyawali D, Iyer R, Ravikumar P, Estrera AS, Hsia CCW. Perfusion-related stimuli for compensatory lung growth following pneumonectomy. J Appl Physiol (1985) 2016; 121:312-23. [PMID: 27150830 DOI: 10.1152/japplphysiol.00297.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 05/04/2016] [Indexed: 12/14/2022] Open
Abstract
Following pneumonectomy (PNX), two separate mechanical forces act on the remaining lung: parenchymal stress caused by lung expansion, and microvascular distension and shear caused by increased perfusion. We previously showed that parenchymal stress and strain explain approximately one-half of overall compensation; the remainder was presumptively attributed to perfusion-related factors. In this study, we directly tested the hypothesis that perturbation of regional pulmonary perfusion modulates post-PNX lung growth. Adult canines underwent banding of the pulmonary artery (PAB) to the left caudal (LCa) lobe, which caused a reduction in basal perfusion to LCa lobe without preventing the subsequent increase in its perfusion following right PNX while simultaneously exaggerating the post-PNX increase in perfusion to the unbanded lobes, thereby creating differential perfusion changes between banded and unbanded lobes. Control animals underwent sham pulmonary artery banding followed by right PNX. Pulmonary function, regional pulmonary perfusion, and high-resolution computed tomography of the chest were analyzed pre-PNX and 3-mo post-PNX. Terminally, the remaining lobes were fixed for detailed morphometric analysis. Results were compared with corresponding lobes in two control (Sham banding and normal unoperated) groups. PAB impaired the indices of post-PNX extravascular alveolar tissue growth by up to 50% in all remaining lobes. PAB enhanced the expected post-PNX increase in alveolar capillary formation, measured by the prevalence of double-capillary profiles, in both unbanded and banded lobes. We conclude that perfusion distribution provides major stimuli for post-PNX compensatory lung growth independent of the stimuli provided by lung expansion and parenchymal stress and strain.
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Affiliation(s)
- D Merrill Dane
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Cuneyt Yilmaz
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Dipendra Gyawali
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Roshni Iyer
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Priya Ravikumar
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Aaron S Estrera
- Department of Cardiothoracic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Connie C W Hsia
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
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Musk GC, Polglase GR, Bunnell JB, Nitsos I, Tingay D, Pillow JJ. A comparison of high-frequency jet ventilation and synchronised intermittent mandatory ventilation in preterm lambs. Pediatr Pulmonol 2015; 50:1286-93. [PMID: 25823397 DOI: 10.1002/ppul.23187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 02/08/2015] [Accepted: 03/15/2015] [Indexed: 01/12/2023]
Abstract
PURPOSE Synchronised intermittent mandatory ventilation (SIMV) and high-frequency jet ventilation (HFJV) are accepted ventilatory strategies for treatment of respiratory distress syndrome (RDS) in preterm babies. We hypothesised that SIMV and HFJV both facilitate adequate oxygenation and ventilation but that HFJV is associated with less lung injury. RESULTS There were no differences in arterial oxygenation or partial pressure of carbon dioxide despite lower mean airway pressure during SIMV for most of the study. There were no consistent significant differences in end systolic and end diastolic PBF, lung injury data and static lung compliance. METHODS Preterm lambs of anaesthetised ewes were instrumented, intubated and delivered by caesarean section after intratracheal suction and instillation of surfactant. Each lamb was managed for 3 hr according to a predetermined algorithm for ventilatory support consistent with open lung ventilation. Pulmonary blood flow (PBF) was measured continuously and pulsatility index was calculated. Ventilatory parameters were recorded and arterial blood gases were measured at intervals. At postmortem, in situ pressure-volume deflation curves were recorded, and bronchoalveolar lavage fluid and lung tissue were obtained to assess inflammation. CONCLUSIONS SIMV and HFJV have comparable clinical efficacy and ventilator pressure requirements when applied with a targeted lung volume recruitment strategy.
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Affiliation(s)
- Gabrielle C Musk
- Animal Care Services, Faculty of Medicine Dentistry and Health Sciences, University of Western Australia, Perth, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Australia
| | - J Bert Bunnell
- Department of Bioengineering, University of Utah, Bunnell Inc, Salt Lake City, Utah
| | - Ilias Nitsos
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Australia
| | - David Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia
| | - J Jane Pillow
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Australia.,School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Australia
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Walker SC, Asadi AK, Hopkins SR, Buxton RB, Prisk GK. A statistical clustering approach to discriminating perfusion from conduit vessel signal contributions in a pulmonary ASL MR image. NMR Biomed 2015; 28:1117-1124. [PMID: 26182890 PMCID: PMC4537803 DOI: 10.1002/nbm.3358] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 05/17/2015] [Accepted: 06/14/2015] [Indexed: 06/04/2023]
Abstract
The measurement of pulmonary perfusion (blood delivered to the capillary bed within a voxel) using arterial spin labeling (ASL) magnetic resonance imaging is often complicated by signal artifacts from conduit vessels that carry blood destined for voxels at a distant location in the lung. One approach to dealing with conduit vessel contributions involves the application of an absolute threshold on the ASL signal. While useful for identifying a subset of the most dominant high signal conduit image features, signal thresholding cannot discriminate between perfusion and conduit vessel contributions at intermediate and low signal. As an alternative, this article discusses a data-driven statistical approach based on statistical clustering for characterizing and discriminating between capillary perfusion and conduit vessel contributions over the full signal spectrum. An ASL flow image is constructed from the difference between a pair of tagged magnetic resonance images. However, when viewed as a bivariate projection that treats the image pair as independent measures (rather than the univariate quantity that results from the subtraction of the two images), the signal associated with capillary perfusion contributions is observed to cluster independently of the signal associated with conduit vessel contributions. Analyzing the observed clusters using a Gaussian mixture model makes it possible to discriminate between conduit vessel and capillary-perfusion-dominated signal contributions over the full signal spectrum of the ASL image. As a demonstration of feasibility, this study compares the proposed clustering approach with the standard absolute signal threshold strategy in a small number of test images.
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Affiliation(s)
| | - Amran K. Asadi
- Department of Medicine, University of California, San Diego
| | - Susan R. Hopkins
- Department of Medicine, University of California, San Diego
- Department of Radiology, University of California, San Diego
| | | | - G. Kim Prisk
- Department of Medicine, University of California, San Diego
- Department of Radiology, University of California, San Diego
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36
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Asadi AK, Sá RC, Kim NH, Theilmann RJ, Hopkins SR, Buxton RB, Prisk GK. Inhaled nitric oxide alters the distribution of blood flow in the healthy human lung, suggesting active hypoxic pulmonary vasoconstriction in normoxia. J Appl Physiol (1985) 2014; 118:331-43. [PMID: 25429099 DOI: 10.1152/japplphysiol.01354.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is thought to actively regulate ventilation-perfusion (V̇a/Q̇) matching, reducing perfusion in regions of alveolar hypoxia. We assessed the extent of HPV in the healthy human lung using inhaled nitric oxide (iNO) under inspired oxygen fractions (FiO2 ) of 0.125, 0.21, and 0.30 (a hyperoxic stimulus designed to abolish HPV without the development of atelectasis). Dynamic measures of blood flow were made in a single sagittal slice of the right lung of five healthy male subjects using an arterial spin labeling (ASL) MRI sequence, following a block stimulus pattern (3 × 60 breaths) with 40 ppm iNO administered in the central block. The overall spatial heterogeneity, spatiotemporal variability, and regional pattern of pulmonary blood flow was quantified as a function of condition (FiO2 × iNO state). While spatial heterogeneity did not change significantly with iNO administration or FiO2 , there were statistically significant increases in Global Fluctuation Dispersion, (a marker of spatiotemporal flow variability) when iNO was administered during hypoxia (5.4 percentage point increase, P = 0.003). iNO had an effect on regional blood flow that was FiO2 dependent (P = 0.02), with regional changes in the pattern of blood flow occurring in hypoxia (P = 0.007) and normoxia (P = 0.008) tending to increase flow to dependent lung at the expense of nondependent lung. These findings indicate that inhaled nitric oxide significantly alters the distribution of blood flow in both hypoxic and normoxic healthy subjects, and suggests that some baseline HPV may indeed be present in the normoxic lung.
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Affiliation(s)
- Amran K Asadi
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Rui Carlos Sá
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Nick H Kim
- Department of Medicine, University of California, San Diego, La Jolla, California; and
| | - Rebecca J Theilmann
- Department of Radiology, University of California, San Diego, La Jolla, California
| | - Susan R Hopkins
- Department of Medicine, University of California, San Diego, La Jolla, California; and Department of Radiology, University of California, San Diego, La Jolla, California
| | - Richard B Buxton
- Department of Radiology, University of California, San Diego, La Jolla, California
| | - G Kim Prisk
- Department of Medicine, University of California, San Diego, La Jolla, California; and Department of Radiology, University of California, San Diego, La Jolla, California
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Lang JAR, Pearson JT, te Pas AB, Wallace MJ, Siew ML, Kitchen MJ, Fouras A, Lewis RA, Wheeler KI, Polglase GR, Shirai M, Sonobe T, Hooper SB. Ventilation/perfusion mismatch during lung aeration at birth. J Appl Physiol (1985) 2014; 117:535-43. [PMID: 24994883 DOI: 10.1152/japplphysiol.01358.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
At birth, the transition to newborn life is triggered by lung aeration, which stimulates a large increase in pulmonary blood flow (PBF). Current theories predict that the increase in PBF is spatially related to ventilated lung regions as they aerate after birth. Using simultaneous phase-contrast X-ray imaging and angiography we investigated the spatial relationships between lung aeration and the increase in PBF after birth. Six near-term (30-day gestation) rabbits were delivered by caesarean section, intubated and an intravenous catheter inserted, before they were positioned for X-ray imaging. During imaging, iodine was injected before ventilation onset, after ventilation of the right lung only, and after ventilation of both lungs. Unilateral ventilation increased iodine levels entering both left and right pulmonary arteries (PAs) and significantly increased heart rate, iodine ejection per beat, diameters of both left and right PAs, and number of visible vessels in both lungs. Within the 6th intercostal space, the mean gray level (relative measure of iodine level) increased from 68.3 ± 11.6 and 70.3 ± 7.5%·s to 136.3 ± 22.6 and 136.3 ± 23.7%·s in the left and right PAs, respectively. No differences were observed between vessels in the left and right lungs, despite the left lung not initially being ventilated. The increase in PBF at birth is not spatially related to lung aeration allowing a large ventilation/perfusion mismatch, or pulmonary shunting, to occur in the partially aerated lung at birth.
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Affiliation(s)
- Justin A R Lang
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - James T Pearson
- Monash Biomedical Imaging, Melbourne, Australia; Australian Synchrotron, Melbourne, Australia
| | - Arjan B te Pas
- Department of Pediatrics, Leiden University Medical Centre, Leiden, Netherlands
| | - Megan J Wallace
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Melissa L Siew
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | | | - Andreas Fouras
- Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia
| | - Robert A Lewis
- Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia; Department of Medical Imaging, University of Saskatchewan, Saskatoon, Canada
| | - Kevin I Wheeler
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Royal Hobart Hospital, Hobart, Australia; and
| | - Graeme R Polglase
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Takashi Sonobe
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Stuart B Hooper
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia;
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Pouzot C, Richard JC, Gros A, Costes N, Lavenne F, Le Bars D, Guerin C. Noninvasive quantitative assessment of pulmonary blood flow with 18F-FDG PET. J Nucl Med 2013; 54:1653-60. [PMID: 23907755 DOI: 10.2967/jnumed.112.116699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Pulmonary blood flow (PBF) is a critical determinant of oxygenation during acute lung injury (ALI). PET/CT with (18)F-FDG allows the assessment of both lung aeration and neutrophil inflammation as well as an estimation of the regional fraction of blood (FB) if compartmental modeling is used to quantify (18)F-FDG pulmonary uptake. The aim of this study was to validate the use of FB to assess PBF, with PET and compartmental modeling of (15)O-H2O kinetics as a reference method, in both control animals and animals with ALI. For the purpose of studying a wide range of PBF values, supine and prone positions and various positive end-expiratory pressures (PEEPs) and tidal volumes (V(T)s) were selected. METHODS Pigs were randomized into 3 groups in which ALI was induced by HCl inhalation: pigs studied in the supine position with a low PEEP (5 ± 3 [mean ± SD] cm of H2O; n = 9) or a high PEEP (12 ± 1 cm of H2O; n = 8) and pigs studied in the prone position with a low PEEP (6 ± 3 cm of H2O; n = 9). Also included were a control group that did not have ALI (n = 6) and 2 additional groups (n = 6 each) that had a high V(T) to maintain a transpulmonary pressure of greater than or equal to 35 cm of H2O and that either received HCl inhalation or did not receive HCl inhalation. PBF and FB were measured with PET and compartmental modeling of (15)O-H2O and (18)F-FDG kinetics in 10 lung regions along the anterior-to-posterior lung dimension, and both were expressed in each region as a fraction of their values in the whole lung. RESULTS PBF and FB were strongly correlated (R(2) = 0.9), with a slope of the regression line close to unity and a negligible intercept. The mean difference between PBF and FB was 0, and the 95% limits of agreement were -0.035 to 0.035. This good agreement between methods was obtained in both normal and injured lungs and under a wide range of V(T), PEEP, and regional PBF values (7-71 mL/kg, 0-15 cm of H2O, and 24-603 mL·min(-1)·100 mL of lung(-1), respectively). CONCLUSION FB assessed with (18)F-FDG is a good surrogate for PBF in both normal animals and animals with ALI. PET/CT has the potential to be used to study ventilation, perfusion, and lung inflammation with a single tracer.
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Affiliation(s)
- Céline Pouzot
- Service Siamu, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France
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Schantz DI, Chen RP. A practical method of measuring oxygen consumption in children with complex mixing circulations by the use of thermodilution cardiac output studies. J Thorac Cardiovasc Surg 2013; 146:1179-84. [PMID: 23380516 DOI: 10.1016/j.jtcvs.2012.09.103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Revised: 09/06/2012] [Accepted: 09/21/2012] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We describe a method to measure oxygen consumption (VO2) and pulmonary vascular resistive index (PVRI) based on thermodilution cardiac output in patients with complex mixing circulations. We apply this method to patients with a bidirectional cavopulmonary anastomosis (BDCPA). We compare our measured VO2 with a predicted VO2 based on a formula using height and weight. METHODS We reviewed data based on cardiac catheterization and thermodilution cardiac output in a series of 25 catheterizations in patients with BDCPA. We used this data to measure VO2 and PVRI, and looked for a correlation between the predicted and measured VO2. We also assessed whether any other hemodynamic parameter correlated with measured VO2. RESULTS There was no significant correlation between the predicted and the measured VO2 (correlation coefficient = -0.258, P = .21). We did find a significant correlation in the difference between the measured and predicted VO2 against the measured VO2 such that at a lower measured VO2 the predictive formula tended to overestimate VO2 and at a higher VO2 the formula underestimated VO2 (correlation coefficient = 0.963, P < .0001). Body surface area did not correlate with measured VO2 (correlation coefficient = 0.28, P < .16). Mixed venous oxygen content showed a weak negative correlation with VO2 (correlation coefficient = -0.54, P = .005). CONCLUSIONS An assessment of PVRI that is based on a predicted VO2 is unreliable in this patient population. No hemodynamic parameter correlated well with VO2. The use of a measured VO2 is necessary in determining PVRI in these patients.
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Abstract
Increased pulmonary blood flow (PBF) is widely thought to provoke pulmonary vascular obstructive disease (PVO), but the impact of wall shear stress in the lung is actually poorly defined. We examined information from patients having cardiac lesions which impact the pulmonary circulation in distinct ways, as well as experimental studies, asking how altered hemodynamics impact the risk of developing PVO. Our results are as follows: (1) with atrial septal defect (ASD; increased PBF but low PAP), shear stress may be increased but there is little tendency to develop PVO; (2) with normal PBF but increased pulmonary vascular resistance (PVR; mitral valve disease) shear stress may also be increased but risk of PVO still low; (3) with high PVR and PBF (e.g., large ventricular septal defect), wall shear stress is markedly increased and the likelihood of developing PVO is much higher than with high PBF or PAP only; and (4) with ASD, experimental and clinical observations suggest that increased PBF plus another stimulus (e.g., endothelial inflammation) may be required for PVO. We conclude that modestly increased wall shear stress (e.g., ASD) infrequently provokes PVO, and likely requires other factors to be harmful. Likewise, increased PAP seldom causes PVO. Markedly increased wall shear stress may greatly increase the likelihood of PVO, but we cannot discriminate its effect from the combined effects of increased PAP and PBF. Finally, the age of onset of increased PAP may critically impact the risk of PVO. Some implications of these observations for future investigations are discussed.
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Affiliation(s)
- Thomas J Kulik
- Department of Cardiology, Division of Cardiac Critical Care, and the Pulmonary Hypertension Program, Children's Hospital Boston, Boston, Massachusetts, USA
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Clark AR, Burrowes KS, Tawhai MH. Contribution of serial and parallel microperfusion to spatial variability in pulmonary inter- and intra-acinar blood flow. J Appl Physiol (1985) 2010; 108:1116-26. [PMID: 20110543 PMCID: PMC2867543 DOI: 10.1152/japplphysiol.01177.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Accepted: 01/22/2010] [Indexed: 11/22/2022] Open
Abstract
This study presents a theoretical model of combined series and parallel perfusion in the human pulmonary acinus that maintains computational simplicity while capturing some important features of acinar structure. The model provides a transition between existing models of perfusion in the large pulmonary blood vessels and the pulmonary microcirculation. Arterioles and venules are represented as distinct elastic vessels that follow the branching structure of the acinar airways. These vessels are assumed to be joined at each generation by capillary sheets that cover the alveoli present at that generation, forming a "ladderlike" structure. Compared with a model structure in which capillary beds connect only the most distal blood vessels in the acinus, the model with combined serial and parallel perfusion provides greater capacity for increased blood flow in the lung via capillary recruitment when the blood pressure is elevated. Stratification of acinar perfusion emerges in the model, with red blood cell transit time significantly larger in the distal portion of the acinus compared with the proximal portion. This proximal-to-distal pattern of perfusion may act in concert with diffusional screening to optimize the potential for gas exchange.
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Affiliation(s)
- A R Clark
- Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand.
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Henderson AC, Prisk GK, Levin DL, Hopkins SR, Buxton RB. Characterizing pulmonary blood flow distribution measured using arterial spin labeling. NMR Biomed 2009; 22:1025-35. [PMID: 19492332 PMCID: PMC2836845 DOI: 10.1002/nbm.1407] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The arterial spin labeling (ASL) method provides images in which, ideally, the signal intensity of each image voxel is proportional to the local perfusion. For studies of pulmonary perfusion, the relative dispersion (RD, standard deviation/mean) of the ASL signal across a lung section is used as a reliable measure of flow heterogeneity. However, the RD of the ASL signals within the lung may systematically differ from the true RD of perfusion because the ASL image also includes signals from larger vessels, which can reflect the blood volume rather than blood flow if the vessels are filled with tagged blood during the imaging time. Theoretical studies suggest that the pulmonary vasculature exhibits a lognormal distribution for blood flow and thus an appropriate measure of heterogeneity is the geometric standard deviation (GSD). To test whether the ASL signal exhibits a lognormal distribution for pulmonary blood flow, determine whether larger vessels play an important role in the distribution, and extract physiologically relevant measures of heterogeneity from the ASL signal, we quantified the ASL signal before and after an intervention (head-down tilt) in six subjects. The distribution of ASL signal was better characterized by a lognormal distribution than a normal distribution, reducing the mean squared error by 72% (p < 0.005). Head-down tilt significantly reduced the lognormal scale parameter (p = 0.01) but not the shape parameter or GSD. The RD increased post-tilt and remained significantly elevated (by 17%, p < 0.05). Test case results and mathematical simulations suggest that RD is more sensitive than the GSD to ASL signal from tagged blood in larger vessels, a probable explanation of the change in RD without a statistically significant change in GSD. This suggests that the GSD is a useful measure of pulmonary blood flow heterogeneity with the advantage of being less affected by the ASL signal from tagged blood in larger vessels.
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Affiliation(s)
- A Cortney Henderson
- Department of Medicine, Division of Physiology, University of California, San Diego, La Jolla, CA 92093-0931, USA.
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