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Maybauer DM, Talke PO, Westphal M, Maybauer MO, Traber LD, Enkhbaatar P, Morita N, Traber DL. Positive End-expiratory Pressure Ventilation Increases Extravascular Lung Water Due to a Decrease in Lung Lymph Flow. Anaesth Intensive Care 2019; 34:329-33. [PMID: 16802485 DOI: 10.1177/0310057x0603400307] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Positive end-expiratory pressure (PEEP) is used to improve gas exchange, increase functional residual capacity, recruit air spaces, and decrease pulmonary shunt in patients suffering from respiratory failure. The effect of PEEP on extravascular lung water (EVLW), however, is still not fully understood. This study was designed as a prospective laboratory experiment to evaluate the effects of PEEP on EVLW and pulmonary lymph flow (QL) under physiologic conditions. Twelve adult sheep were operatively prepared to measure haemodynamics of the systemic and pulmonary circulation, and to assess EVLW. In addition, the lung lymphatic duct was cannulated and a tracheostomy performed. The animals were then mechanically ventilated in the awake-state without end-expiratory pressure (PEEP 0). After a two-hour baseline period, PEEP was increased to 10 cmH2O for the duration of two hours, and then reduced back to 0 cmH2O. Cardiopulmonary variables, QL, and arterial blood gases were recorded intermittently; EVLW was determined two hours after each change in PEEP. The increase in PEEP resulted in a decrease in QL (7±1 vs 5±1 ml/h) and an increase in EVLW (498±40 vs 630±58 ml; P<0.05 each) without affecting cardiac output. As PEEP was decreased back to baseline, QL increased significantly (5±1 vs 10±2 ml/h), whereas EVLW returned back to baseline. This study suggests that institution of PEEP produces a reversible increase in EVLW that is linked to a decrease in QL.
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Affiliation(s)
- D M Maybauer
- Department of Anaesthesiology, Investigational Intensive Care Unit, The University of Texas Medical Branch, and Shriners Burns Hospital for Children at Galveston, USA
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Au SY, Lau CL, Chen KK, Cheong AP, Tong YT, Chan LK. Hemodynamic Effects of Noninvasive Positive-Pressure Ventilation Assessed Using Transthoracic Echocardiography. J Cardiovasc Echogr 2018; 28:114-119. [PMID: 29911008 PMCID: PMC5989542 DOI: 10.4103/jcecho.jcecho_53_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aims: The aim of this study is to measure the effect of positive-pressure ventilation on heart chamber dimensions, left ventricular (LV) systolic function, LV diastolic function, right ventricular (RV) systolic function, and RV pressure using transthoracic echocardiography. Settings and Design: This is a prospective study in a single secondary health-care center. Materials and Methods: A total of 107 patients with obstructive sleep apnea on continuous positive airway pressure (CPAP) therapy were recruited as participants between April and September 2016. Transthoracic echocardiography was performed twice on each participant, before and 15 min after, they used their own CPAP machines, and the echocardiography parameters of both scans were compared. Statistical Analysis Used: The parametric paired t-test was used to compare heart chamber dimensions, left heart diastolic function, left heart systolic function, right heart systolic function, and right heart pressure effect, without and with CPAP. These data were further examined among several subgroups defined by CPAP when the cutoff point was set at 8 cmH2O and 10 cmH2O. The level of significance was set at 0.05. Statistical analyses were performed using IBM SPSS version 22 (IBM, Armonk, NY, USA). Results: There were statistically significant reductions, after the application of CPAP, in the heart dimensions, and LV and RV systolic function. There were no significant changes in diastolic function. Concerning right heart pressure, with CPAP, there was a significant increase in the inferior vena cava (IVC) diameter and there was also a significant decrease in IVC variability from 44.56% ± 14.86% to 36.12% ± 11.42%. The maximum velocity of tricuspid regurgitation (TR) decreased significantly from 180.66 ± 6.95 cm/s to 142.30 ± 52.73 cm/s. Such changes were observed in both low and high CPAP subgroups. Conclusions: When placed on positive pressure, the clinically significant change in IVC diameter and variability and change in trans-TR velocity mean that it would be inaccurate to predict right heart chamber pressure through echocardiogram. Alternative methods for predicting right heart pressure are recommended.
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Affiliation(s)
- Shek Yin Au
- Department of Medicine and Intensive Care Unit, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China
| | - Cheuk Ling Lau
- Department of Medicine and Intensive Care Unit, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China
| | - Ka King Chen
- Department of Medicine and Intensive Care Unit, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China
| | - Adrian Piers Cheong
- Department of Medicine and Intensive Care Unit, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China
| | - Ying Ting Tong
- Division of Nursing and Health Studies, School of Science and Technology, The Open University of Hong Kong, Hong Kong, China
| | - Lip Kiong Chan
- Department of Medicine and Intensive Care Unit, Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China
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Luo M, Lin J, Qin Z, Du L. Prevention preferable to treatment: 3 case reports of patients experiencing right-sided heart failure after Ebstein anomaly correction. Medicine (Baltimore) 2017; 96:e5627. [PMID: 28072699 PMCID: PMC5228659 DOI: 10.1097/md.0000000000005627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
RATIONALE Ebstein anomaly is a common congenital heart disease that may induce severe tricuspid regurgitation and dilation of the "atrialized" portion of the right ventricle. Patients who undergo surgery to correct Ebstein anomaly are at high risk of postoperative right-sided heart failure, yet little is known about what pre-, peri-, or postoperative procedures may help reduce this risk. PATIENT CONCERNS Here, we describe 3 cases of adults with Ebstein anomaly who underwent corrective surgery and in whom right-sided heart failure occurred with severe tricuspid regurgitation detected by transesophageal echocardiography. DIAGNOSES Ebstein anomaly. INTERVENTION Various approaches were applied to prevent right heart failure: perioperative control of atrial and ventricle arrhythmia, protection of myocardium, reduction of right-side cardiac workload after cardiopulmonary bypass, and mechanical support for right heart. OUTCOMES One of the 3 patients died, another experienced kidney failure despite postoperative support on extracorporeal membrane oxygenation, and the third patient survived without complications. LESSONS Our case series suggests that surgical prognosis can be improved through aggressive preoperative treatment, vasoactive and anti-arrhythmia medications, and comprehensive measures designed to reduce myocardial injury, prevent myocardial edema, and reduce pre- and afterload on the right ventricle.
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Redington AN. Low cardiac output due to acute right ventricular dysfunction and cardiopulmonary interactions in congenital heart disease (2013 Grover Conference series). Pulm Circ 2014; 4:191-9. [PMID: 25006438 DOI: 10.1086/675982] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 01/17/2014] [Indexed: 11/03/2022] Open
Abstract
The importance of right ventricular dysfunction, as a driver of symptoms and outcomes in the normal biventricular circulation, is increasingly recognized. However, the pathophysiologic mechanisms underlying the role of the right ventricle in acute and chronic hemodynamic deterioration are less well understood. This review aims to clarify the impact of acute right ventricular dysfunction on biventricular interactions and, in turn, to discuss the role of cardiopulmonary interactions in the normal circulation and when modified by the presence of associated structural malformations. Such interactions may be adverse or beneficial, and a more complete understanding of their importance may result in novel therapeutic strategies and improved outcomes.
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Affiliation(s)
- Andrew N Redington
- Division of Cardiology, Hospital for Sick Children, and Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
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Affiliation(s)
- Mark K. Friedberg
- From the Labatt Family Heart Center, Department of Paediatrics, Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Andrew N. Redington
- From the Labatt Family Heart Center, Department of Paediatrics, Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
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Calafiore AM, Bartoloni G, Amri HA, Iacò AL, Abukhudair W, Lanzaro BI, Mauro MD. Functional tricuspid regurgitation and the right ventricle: what we do not know is more than we know. Expert Rev Cardiovasc Ther 2014; 10:1351-66. [DOI: 10.1586/erc.12.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Giannini C, Petronio AS, De Carlo M, Guarracino F, Conte L, Fiorelli F, Pieroni A, Di Bello V. Integrated reverse left and right ventricular remodelling after MitraClip implantation in functional mitral regurgitation: an echocardiographic study. Eur Heart J Cardiovasc Imaging 2013; 15:95-103. [DOI: 10.1093/ehjci/jet141] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Neema PK, Manikandan S, Chandran DA, Rathod RC, Mittnacht AJ, Love BA, Daves SM, Bachman C. Case 5--2011: Acute respiratory distress syndrome in an infant after repair of tetralogy of Fallot. J Cardiothorac Vasc Anesth 2011; 25:867-73. [PMID: 21962301 PMCID: PMC9941529 DOI: 10.1053/j.jvca.2011.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Indexed: 11/11/2022]
Affiliation(s)
- Praveen Kumar Neema
- Department of Anaesthesiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India.
| | - Sethuraman Manikandan
- Department of Anaesthesiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India
| | - Divya Amol Chandran
- Department of Anaesthesiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India
| | - Ramesh Chandra Rathod
- Department of Anaesthesiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India
| | | | - Barry A. Love
- Congenital Cardiac Catheterization Laboratory, The Mount Sinai Medical Center, New York, NY
| | - Suanne M. Daves
- Division of Pediatric Cardiac Anesthesia, The Pediatric Heart Institute, Monroe Carell Jr Children's Hospital at Vanderbilt, Nashville, TN
| | - Catherine Bachman
- Department of Anesthesia and Critical Care, The University of Chicago Medical Center, Chicago, IL
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Oxborough D, Whyte G, Wilson M, O'Hanlon R, Birch K, Shave R, Smith G, Godfrey R, Prasad S, George K. A Depression in Left Ventricular Diastolic Filling following Prolonged Strenuous Exercise is Associated with Changes in Left Atrial Mechanics. J Am Soc Echocardiogr 2010; 23:968-76. [DOI: 10.1016/j.echo.2010.06.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Indexed: 10/19/2022]
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Squara P, Rotcajg D, Denjean D, Estagnasie P, Brusset A. Comparison of monitoring performance of Bioreactance vs. pulse contour during lung recruitment maneuvers. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:R125. [PMID: 19638227 PMCID: PMC2750178 DOI: 10.1186/cc7981] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 06/30/2009] [Accepted: 07/28/2009] [Indexed: 12/18/2022]
Abstract
INTRODUCTION This study was designed to test the hypothesis of equivalence in cardiac output (CO) and stroke volume (SV) monitoring capabilities of two devices: non invasive transthoracic bioreactance (NICOM), and a pulse contour analysis (PICCO PC) coupled to transpulmonary thermodilution (PICCO TD). METHODS We included consecutive patients of a single ICU following cardiac surgery. Continuous minute-by-minute hemodynamic variables obtained from NICOM and PICCO PC were recorded and compared in 20 patients at baseline, during a lung recruitment maneuver (20 cmH2O of PEEP) and following withdrawal of PEEP. PICCO TD measurements were also determined. We evaluated the accuracy of these two technologies at baseline using PICCO TD as reference and we estimated the precision by the fluctuation around the mean value (2SD/mean). Then, we assessed time response, amplitude response and reliability for detecting expected decreases when PEEP was applied. Type I and type II errors were analyzed. RESULTS CO values (PICCO TD) ranged from 1.6 to 8.0 L.min-1. At baseline, CO values were comparable for NICOM, PICCO PC and PICCO TD: 5.0 +/- 1.2, 4.7 +/- 1.4 and 4.6 +/- 1.3 L.min.-1, respectively (NS). Limits of agreements with PICCO TD were 1.52 L.min.-1 for NICOM and 1.77 L.min.-1 for PICCO PC, NS. The 95% statistical power gives an equivalence with a threshold of 0.52 L.min.-1 for NICOM vs. PICCO PC. The CO precision was 6 +/- 3% and 6 +/- 5% for NICOM and PICCO PC, respectively, NS. When PEEP was applied, CO was reduced by 33 +/- 12%, 31 +/- 14% and 32 +/- 13%, for NICOM, PICCO PC and PICCO TD, respectively (NS). Time response was 3.2 +/- 0.7 minute for NICOM vs. 2 +/- 0.5 minute for PICCO PC (NS). SV results were comparable to those for CO. CONCLUSIONS Although limited to 20 patients, this study has enough power to show comparable CO and SV monitoring capabilities of Bioreactance and pulse contour analysis calibrated by transpulmonary thermodilution.
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Affiliation(s)
- Pierre Squara
- ICU, Clinique Ambroise Paré, 27 bd Victor Hugo, 92200 Neuiily-sur-Seine, France.
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Jungebluth P, Iglesias M, Go T, Sibila O, Macchiarini P. Optimal Positive End-Expiratory Pressure During Pumpless Extracorporeal Lung Membrane Support. Artif Organs 2008; 32:885-90. [DOI: 10.1111/j.1525-1594.2008.00646.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nakagawa R, Koizumi T, Ono K, Tsushima K, Yoshikawa S, Kubo K, Otagiri T. Cardiovascular responses to high-frequency oscillatory ventilation during acute lung injury in sheep. J Anesth 2007; 21:340-7. [PMID: 17680186 DOI: 10.1007/s00540-007-0508-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
PURPOSE The present study was designed to evaluate pulmonary and systemic hemodynamics and blood gas changes on switching from conventional mechanical ventilation (CMV) to high-frequency oscillatory ventilation (HFOV) in a large animal model of acute lung injury. METHODS Eleven anesthetised sheep chronically instrumented with vascular monitoring were prepared. Animals received oleic acid (0.08 ml x kg(-1)) intravenously and were ventilated for 4 h h after the administration of oleic acid. The animals were then randomized into the two following different ventilation modes: CMV (tidal volume [V(T)], 6 ml x kg(-1); respiratory rate [RR], 25 x min(-1)) with positive end-expiratory pressure (PEEP) of 12 cmH(2)O; or CMV under the same settings without PEEP. HFOV was then switched. The setting of mean airway pressure with a fixed stroke volume was changed between 25, 18, and 12 cmH(2)O every 20 min. Mean pulmonary artery pressure, pulmonary artery occlusive pressure (Paop), left atrium pressure, systemic arterial pressure, cardiac output (CO), and blood gas composition under each setting were measured before and after HFOV. RESULTS Switching to HFOV, from without PEEP, resulted in significant increases in Paop and PaO2 and a decrease in CO at higher (25, 18 cmH(2)O) mean airway pressure. However, when changed from low V(T) and PEEP, HFOV produced further improvements in oxygenation without any deterioration of cardiovascular depression. Thus, switching to HFOV from CMV with low V(T) and high PEEP may have little influence on pulmonary or systemic hemodynamics in acute lung injury. CONCLUSION We conclude that hemodynamic responses are dependent on the predefined setting of PEEP during CMV, and on applied mean airway pressure during HFOV.
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Affiliation(s)
- Rikimaru Nakagawa
- Anesthesiology and Resuscitation, Shinshu University School of Medicine, Matsumoto, Japan
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Polglase GR, Wallace MJ, Morgan DL, Hooper SB. Increases in lung expansion alter pulmonary hemodynamics in fetal sheep. J Appl Physiol (1985) 2006; 101:273-82. [PMID: 16575019 DOI: 10.1152/japplphysiol.01544.2005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prolonged increases in fetal lung expansion stimulate fetal lung growth and development, but the effects on pulmonary hemodynamics are unknown. Our aim was to determine the effect of increased fetal lung expansion, induced by tracheal obstruction (TO), on pulmonary blood flow (PBF) and vascular resistance (PVR). Chronically catheterized fetal sheep ( n = 6) underwent TO from 120 to 127 days of gestational age (term ∼147 days); tracheas were not obstructed in control fetuses ( n = 6). PBF, PVR, and changes to the PBF waveform were determined. TO significantly increased lung wet weight compared with control (166.3 ± 20.2 vs. 102.0 ± 18.8 g; P < 0.05). Despite the increase in intraluminal pressure caused by TO (5.0 ± 0.9 vs. 2.4 ± 1.0 mmHg; P < 0.001), PBF and PVR were similar between groups after 7 days (TO 28.1 ± 3.2 vs. control 34.1 ± 10.0 ml·min−1·100 g lung wt−1). However, TO markedly altered pulmonary hemodynamics associated with accentuated fetal breathing movements, causing a reduction rather than an increase in PBF at 7 days of TO. To account for the increase in intraluminal pressure, the pressure was equalized by draining the lungs of liquid on day 7 of TO. Pressure equalization increased PBF from 36.8 ± 5.2 to 112.4 ± 22.8 ml/min ( P = 0.01) and markedly altered the PBF waveform. These studies provide further evidence to indicate that intraluminal pressure is an important determinant of PBF and PVR in the fetus. We suggest that the increase in PBF associated with pressure equalization following TO reflects an increase in growth of the pulmonary vascular bed, leading to an increase in its cross-sectional area.
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Affiliation(s)
- Graeme R Polglase
- Fetal and Neonatal Research Group, Department of Physiology, Monash University, Melbourne, Australia.
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Polglase GR, Morley CJ, Crossley KJ, Dargaville P, Harding R, Morgan DL, Hooper SB. Positive end-expiratory pressure differentially alters pulmonary hemodynamics and oxygenation in ventilated, very premature lambs. J Appl Physiol (1985) 2005; 99:1453-61. [PMID: 15890759 DOI: 10.1152/japplphysiol.00055.2005] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In mature lungs, elevated positive end-expiratory pressure (PEEP) reduces pulmonary blood flow (PBF) and increases pulmonary vascular resistance (PVR). However, the effect of PEEP on PBF in preterm infants with immature lungs and a patent ductus arteriosus is unknown. Fetal sheep were catheterized at 124 days of gestation (term ∼147 days), and a flow probe was placed around the left pulmonary artery to measure PBF. At 127 days, lambs were delivered and ventilated from birth with a tidal volume of 5 ml/kg and 4-cmH2O PEEP; PEEP was changed to 0, 8, and 12 cmH2O in random order, returning to 4 cmH2O between each change. Increasing PEEP from 4 to 8 cmH2O and from 4 to 12 cmH2O decreased PBF by 20.5 and 41.0%, respectively, and caused corresponding changes in PVR; reducing PEEP from 4 to 0 cmH2O did not affect PBF. Despite decreasing PBF, increasing PEEP from 4 to 8 cmH2O and 12 cmH2O improved oxygenation of lambs. Increasing and decreasing PEEP from 4 cmH2O significantly changed the contour of the PBF waveform; at a PEEP of 12 cmH2O, end-diastolic flow was reduced by 82.8% and retrograde flow was reestablished. Although increasing PEEP improves oxygenation, it adversely affects PBF and PVR shortly after birth, alters the PBF waveform, and reestablishes retrograde flow during diastole.
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Affiliation(s)
- Graeme R Polglase
- Fetal and Neonatal Research Group, Department of Physiology, Monash University, Australia.
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Mitchell JR, Whitelaw WA, Sas R, Smith ER, Tyberg JV, Belenkie I. RV filling modulates LV function by direct ventricular interaction during mechanical ventilation. Am J Physiol Heart Circ Physiol 2005; 289:H549-57. [PMID: 15792988 DOI: 10.1152/ajpheart.01180.2004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During mechanical ventilation, phasic changes in systemic venous return modulate right ventricular output but may also affect left ventricular function by direct ventricular interaction. In 13 anesthetized, closed-chest, normal dogs, we measured inferior vena cava flow and left and right ventricular dimensions and output during mechanical ventilation, during an inspiratory hold, and (during apnea) vena caval constriction and abdominal compression. During a single ventilation cycle preceded by apnea, positive pressure inspiration decreased caval flow and right ventricular dimension; the transseptal pressure gradient increased, the septum shifted rightward, reflecting an increased left ventricular volume (the anteroposterior diameter did not change); and stroke volume increased. The opposite occurred during expiration. Similarly, the maneuvers that decreased venous return shifted the septum rightward, and left ventricular volume and stroke volume increased. Increased venous return had opposite effects. Changes in left ventricular function caused by changes in venous return alone were similar to those during mechanical ventilation except for minor quantitative differences. We conclude that phasic changes in systemic venous return during mechanical ventilation modulate left ventricular function by direct ventricular interaction.
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Affiliation(s)
- Jamie R Mitchell
- Department of Cardiac Sciences, The Libin Cardiovascular Institute of Alberta, University of calgary, Calgary, Alberta, canada
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Kluckow M, Evans N. Low superior vena cava flow and intraventricular haemorrhage in preterm infants. Arch Dis Child Fetal Neonatal Ed 2000; 82:F188-94. [PMID: 10794784 PMCID: PMC1721081 DOI: 10.1136/fn.82.3.f188] [Citation(s) in RCA: 317] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To document the incidence, timing, degree, and associations of systemic hypoperfusion in the preterm infant and to explore the temporal relation between low systemic blood flow and the development of intraventricular haemorrhage (IVH). STUDY DESIGN 126 babies born before 30 weeks' gestation (mean 27 weeks, mean body weight 991 g) were studied with Doppler echocardiography and cerebral ultrasound at 5, 12, 24, and 48 hours of age. Superior vena cava (SVC) flow was assessed by Doppler echocardiography as the primary measure of systemic blood flow returning from the upper body and brain. Other measures included colour Doppler diameters of ductal and atrial shunts, as well as Doppler assessment of shunt direction and velocity, and right and left ventricular outputs. Upper body vascular resistance was calculated from mean blood pressure and SVC flow. RESULTS SVC flow below the range recorded in well preterm babies was common in the first 24 hours (48 (38%) babies), becoming significantly less common by 48 hours (6 (5%) babies). These low flows were significantly associated with lower gestation, higher upper body vascular resistance, larger diameter ductal shunts, and higher mean airway pressure. Babies whose mothers had received antihypertensives had significantly higher SVC flow during the first 24 hours. Early IVH was already present in 9 babies at 5 hours of age. Normal SVC flows were seen in these babies except in 3 with IVH, which later extended, who all had SVC flow below the normal range at 5 and/or 12 hours. Eight of these 9 babies were delivered vaginally. Late IVH developed in 18 babies. 13 of 14 babies with grade 2 to 4 IVH had SVC flow below the normal range before development of an IVH. Two of 4 babies with grade 1 IVH also had SVC flow below the normal range before developing IVH, and the other 2 had SVC flow in the low normal range. In all, IVH was first seen after the SVC flow had improved, and the grade of IVH related significantly to the severity and duration of low SVC flow. The 9 babies who had SVC flow below the normal range and did not develop IVH or periventricular leucomalacia were considerably more mature (median gestation 28 v 25 weeks). CONCLUSIONS Low SVC flow may result from an immature myocardium struggling to adapt to increased extrauterine vascular resistances. Critically low flow occurs when this is compounded by high mean airway pressure and large ductal shunts out of the systemic circulation. Late IVH is strongly associated with these low flow states and occurs as perfusion improves.
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Affiliation(s)
- M Kluckow
- Royal North Shore Hospital and University of Sydney, Sydney, Australia
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Theres H, Binkau J, Laule M, Heinze R, Hundertmark J, Blobner M, Erhardt W, Baumann G, Stangl K. Phase-related changes in right ventricular cardiac output under volume-controlled mechanical ventilation with positive end-expiratory pressure. Crit Care Med 1999; 27:953-8. [PMID: 10362419 DOI: 10.1097/00003246-199905000-00033] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To examine determinants of right ventricular function throughout the ventilatory cycle under volume-controlled mechanical ventilation with various positive end-expiratory pressure (PEEP) stages. DESIGN Prospective observational animal pilot study. SETTING Animal research laboratory at a university hospital. SUBJECTS Eight healthy swine under volume- controlled mechanical ventilation. INTERVENTIONS Flow probes were implanted in eight swine in order to continuously measure blood flow in the pulmonary artery and inferior vena cava. After a recovery phase of 14 days, the swine were subjected to various PEEP stages (0, 5, 10 cm H2O) during volume-controlled positive pressure ventilation. MEASUREMENTS AND MAIN RESULTS Continuous flow measurement took place in the pulmonary artery and inferior vena cava. Data on standard hemodynamic parameters were additionally acquired. Respiration-phase-specific analysis of right ventricular cardiac output and of additional hemodynamic function parameters followed, after calculation of mean values throughout five respiration cycles. PEEP at 5 cm H2O led to significant decreases in inferior vena cava flow (4.1%), and in right ventricular cardiac output (5.2%); the respective decreases at PEEP 10 cm H2O were 13.9% and 18.3%. In the inspiration phase at PEEP 10 cm H2O, results revealed an overproportionally pronounced decrease in comparison with the expiration phase in inferior vena cava flow (-24.6% vs. -10%) and right ventricular cardiac output (-35% vs. -13.5%). This phenomenon is presumably caused by a PEEP-related increase in mean airway pressure by the amount of 10.7 cm H2O in inspiration. CONCLUSIONS Increases in PEEP during volume-controlled mechanical ventilation leads to respiration-phase-specific reduction of right ventricular cardiac output, with a significantly pronounced decrease during the inspiration phase. This decrease in cardiac output should be taken into particular consideration for patients with already critically reduced cardiac output.
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Affiliation(s)
- H Theres
- Charité, Med. Klinik I, Berlin, Germany.
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Popovich MJ. Moon phases and ocean tides: the relationship between the inspiratory-expiratory phases of mechanical ventilation and right ventricular function. Crit Care Med 1999; 27:864-5. [PMID: 10362399 DOI: 10.1097/00003246-199905000-00007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Shekerdemian LS, Bush A, Lincoln C, Shore DF, Petros AJ, Redington AN. Cardiopulmonary interactions in healthy children and children after simple cardiac surgery: the effects of positive and negative pressure ventilation. HEART (BRITISH CARDIAC SOCIETY) 1997; 78:587-93. [PMID: 9470877 PMCID: PMC1892328 DOI: 10.1136/hrt.78.6.587] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To investigate the effects of cuirass negative pressure ventilation on the cardiac output of a group of anaesthetised children after occlusion of an asymptomatic persistent arterial duct, and a group of paediatric patients in the early postoperative period following cardiopulmonary bypass. DESIGN Prospective study. SETTING The paediatric intensive care unit and catheter laboratory of a tertiary care centre. PATIENTS 16 mechanically ventilated children were studied: seven had undergone surgery for congenital heart disease, and nine cardiac catheterisation for transcatheter occlusion of an isolated asymptomatic persistent arterial duct. INTERVENTIONS Cardiac output was measured using the direct Fick method during intermittent positive pressure ventilation and again after a short period of negative pressure ventilation. In five of the postoperative patients a third measurement was made following reinstitution of positive pressure ventilation. RESULTS Negative pressure ventilation was delivered without complication, with no significant change in systemic arterial oxygen and carbon dioxide tension. The mixed venous saturation increased from 74% to 75.8% in the healthy children, and from 58.9% to 62.3% in the postoperative group. Negative pressure ventilation increased the cardiac index from 4.0 to 4.5 l/min/m2 in the healthy children, and from 2.8 to 3.5 l/min/m2 in the surgical group. The increase was significantly higher in the postoperative patients (28.1%) than the healthy children (10.8%). CONCLUSIONS While offering similar ventilatory efficiency to positive pressure ventilation, cuirass negative pressure ventilation led to a modest improvement in the cardiac output of healthy children, and to a greater increase in postoperative patients. There are important cardiopulmonary interactions in normal children and in children after cardiopulmonary bypass, and by having beneficial effects on these interactions, negative pressure ventilation has haemodynamic advantages over conventional positive pressure ventilation.
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Berglund JE, Haldén E, Jakobson S. Maintained cardiac output during positive end-expiratory pressure ventilation in open-chest pigs. Acta Anaesthesiol Scand 1997; 41:618-23. [PMID: 9181164 DOI: 10.1111/j.1399-6576.1997.tb04753.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Does ventilation with positive end-expiratory pressure (PEEP) act to reduce cardiac output (CO) not only by impeding venous return but also by inducing myocardial depression? The present study was aimed to demonstrate the possible existence of this latter mechanism. METHODS Eight pigs of Swedish native breed weighing 20-25 kg and 10-12 weeks old were anaesthetized, tracheotomized and connected to a volume-controlled ventilator. To prevent intrathoracic pressure from interfering with venous return, the heart and juxtacardiac vessels were exposed to atmospheric pressure by opening and retracting the chest and pericardium. Heart rate (HR), CO, stroke volume (SV), mean arterial (MAP), mean right (MRAP) and left (MLAP) atrial pressures were recorded before and after retransfusion of 500 ml of autologous blood. This procedure was carried out twice in each animal-during ventilation with zero and with 15 cm H2O of PEEP. RESULTS Comparison of the two ventilation modes before volume load revealed negligible differences in HR, CO, SV, MAP, MRAP and MLAP. Moreover, the changes evoked by volume load were practically identical. CONCLUSIONS Addition of PEEP to regular positive pressure ventilation does not induce any haemodynamically detectable myocardial depression in the piglet.
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Affiliation(s)
- J E Berglund
- Department of Anaesthesiology and Intensive Care, University Hospital, Uppsala, Sweden
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23
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Abstract
In this article, we examine 14 studies conducted from 1974 to 1994 on "early" endotracheal extubation (0 to 12 hours postoperatively) in adult cardiac surgery patients. Aspects reviewed include: criteria for patient selection; criteria for extubation; analyses of feasibility and safety; effects of anesthetic technique; and patient morbidity. Advantages and disadvantages of early or "fast-track" extubation are discussed as are directions for future research. Selection criteria varied among studies; patients were most commonly excluded because of severe, preexisting pulmonary disease or ventricular dysfunction. Based on the studies examined, however, at least 70% to 80% of adult patients would meet selection criteria. Three universal criteria were applied in all studies: (1) patient is awake and responsive; (2) adequate gas exchange while breathing spontaneously; and (3) cardiovascular stability. To facilitate early extubation in appropriately selected patients, the choice of anesthetic technique and postoperative sedation technique appears to be important. Anesthetic techniques based on inhalational anesthetic agents, supplemented by moderate doses of narcotics, are more appropriate than high-dose narcotic anesthesia for early extubation protocols. Postoperative sedation with propofol, which has a rapid offset of action, may be particularly advantageous. Every published investigation has concluded that early extubation is safe, feasible, and desirable. Morbidity and mortality have not been shown to be affected by early extubation. Anesthetic technique and the patient's medical condition are the two major factors to consider in accomplishing early extubation.
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Affiliation(s)
- R F Hickey
- Department of Anesthesia, University of California, San Francisco, USA
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Poelaert JI, Visser CA, Everaert JA, De Deyne CS, Decruyenaere J, Colardyn FA. Doppler evaluation of right ventricular outflow impedance during positive-pressure ventilation. J Cardiothorac Vasc Anesth 1994; 8:392-7. [PMID: 7948793 DOI: 10.1016/1053-0770(94)90276-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Positive-pressure ventilation has often been advocated to increase oxygen delivery. This ventilation mode itself, however, can impair right ventricular ejection and, thus, diminish cardiac output. In this study, alterations of right ventricular outflow impedance were evaluated after stepwise increases of positive end-expiratory pressure (PEEP). Different pulmonary artery flow characteristics were evaluated with transesophageal echocardiography in mechanically ventilated postoperative coronary artery bypass surgery patients without pulmonary hypertension. A progressive decrease of pulmonary artery flow velocity and time velocity integrals was found with increasing PEEP levels. No changes in acceleration time or pre-ejection period were observed. In order to decrease the influence of heart rate, the ratios of the different pulmonary artery flow characteristics were calculated. At end-inspiration, both the ratio of acceleration time to right ventricular ejection period and the ratio of pre-ejection period to right ventricular ejection period showed progressive increases above 10 cmH2O positive end-expiratory pressure (13.3% at the level of 15 cmH2O and 8.5% at the level of 20 cmH2O). In this study, acceleration time appears not to be of importance in ventilated patients. These data strongly support the hypothesis that intermittent squeezing of the pulmonary arterial tree during inspiration, rather than positive end-expiratory pressure, creates an increase of right ventricular outflow impedance.
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Affiliation(s)
- J I Poelaert
- Department of Intensive Care, University Hospital, Ghent, Belgium
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25
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Berglund JE, Haldén E, Jakobson S, Landelius J. Echocardiographic analysis of cardiac function during high PEEP ventilation. Intensive Care Med 1994; 20:174-80. [PMID: 8014282 DOI: 10.1007/bf01704696] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Does positive end-expiratory pressure ventilation (PEEP) deteriorate cardiac contractility? DESIGN By means of echocardiography nine piglets were studies during ventilation with 0, 15 and 25 cmH2O (PEEP). Recordings were made before and after 500 ml of 6% dextran 70. MEASUREMENT AND RESULTS Right and left ventricular end-diastolic diameters were plotted against the stroke volume determined by the thermodilution technique. By combining observations made before and after volume expansion during the different ventilation modes, a ventricular function curve was obtained. The slopes of the curves were similar during all three ventilation modes, both on the left and on the right side. CONCLUSION This study indicates undisturbed myocardial contractility during PEEP ventilation. We infer that the cardiac output deterioration in the intact animal is caused entirely by impairment of venous return.
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Affiliation(s)
- J E Berglund
- Department of Anaesthesiology and Intensive Care, University Hospital, Uppsala, Sweden
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26
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Veddeng OJ, Risøe C, Riddervold F, Smiseth OA. Selective positive end-expiratory pressure and right ventricular function in dogs. Acta Anaesthesiol Scand 1994; 38:175-9. [PMID: 8171954 DOI: 10.1111/j.1399-6576.1994.tb03862.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Differential ventilation with selective positive end-expiratory pressure (PEEP) has been shown to reduce cardiac output less than general PEEP. In previous studies we have demonstrated that during selective PEEP left ventricular preload is better maintained than during general PEEP. The present study was designed to determine whether the different haemodynamic responses to selective and general PEEP also might be due to different effects on RV preload. The study was performed on nine acutely instrumented dogs, in which extraventricular pressure was measured by pericardial balloon transducers. Measures of RV preload were obtained by the use of ultrasonic segment length transducers as well as end-diastolic transmural pressure (RVEDP). The study showed reductions in RVEDP during general and selective right (R) PEEP, accompanied by moderate reductions in RV inflow tract segment lengths. These changes were most marked with general PEEP. Selective LPEEP did not change RV preload significantly. Therefore, better maintained cardiac output with selective PEEP than with general PEEP is partly due to less impairment of right ventricular filling.
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Affiliation(s)
- O J Veddeng
- Department of Anaesthesiology, Medical Department B, Rikshospitalet, Oslo, Norway
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27
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28
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Berglund JE, Haldén E, Jakobson S. The effect of peep-ventilation on cardiac function in closed chest pigs. Ups J Med Sci 1994; 99:167-78. [PMID: 7716829 DOI: 10.3109/03009739409179361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Does ventilation with positive end-expiratory pressure (PEEP) depress myocardial contractility? DESIGN Ten piglets were anaesthetized and prepared for the measurement of cardiac output (SV) and right (MRAPtm) and left (MLAPtm) mean transmural atrial pressure, the latter serving as indices of preload. 500 ml of autologous blood was re-transfused during intermittent positive pressure ventilation without PEEP (IPPV) and continuous positive pressure ventilation with 15 cm H2O PEEP (CPPV). MEASUREMENTS AND RESULTS Right and left ventricular function curves were drawn by plotting MRAPtm and MLAPtm respectively versus the corresponding strokevolumes before and after re-transfusion. Similar inclinations were obtained during IPPV and CPPV on either side of the heart. CONCLUSIONS Although the ventricular function curves during IPPV and CPPV covered partially different preload levels, the results suggest that CPPV i.e. PEEP does not affect myocardial contractility.
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Affiliation(s)
- J E Berglund
- Department of Anaesthesiology and Intensive Care, University Hospital, Uppsala, Sweden
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29
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Masouyé PC, Morel DR, Neidhart P. Effect of continuous positive airway pressure applied by face mask on right ventricular function after cardiac surgery. J Cardiothorac Vasc Anesth 1993; 7:551-4. [PMID: 8268435 DOI: 10.1016/1053-0770(93)90313-a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of respiratory therapy with continuous positive airway pressure (CPAP) on right ventricular function 24 hours after elective cardiac surgery was evaluated in patients with or without severe coronary artery disease. The first group included 10 patients following coronary artery bypass graft (CABG) surgery, and the second group included 10 patients following aortic valve replacement (AVR) without preexisting coronary artery disease. Patients of both groups had preoperative left ventricular ejection fractions above 40%. CPAP was applied by face mask at a flow rate of 20 L/min with 40% oxygen in nitrogen and with a positive end-expiratory pressure of 12 cmH2O. Right ventricular function was estimated at end-expiration by a fast-response thermodilution cardiac output catheter. The results demonstrate that in both groups of patients, CPAP did not significantly modify right ventricular indices, ejection fraction, end-systolic and end-diastolic volume indices, and stroke volume index, indicating that CPAP can safely be applied after elective cardiac surgery in patients with or without severe coronary artery disease and preoperative left ventricular ejection fractions above 40%. Furthermore, the concomitant postoperative intravenous infusion of nitroglycerin (to all 10 patients of the CABG group and to 4 patients of the AVR group) counteracted the expected beneficial effect of CPAP therapy on arterial oxygenation.
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Affiliation(s)
- P C Masouyé
- Department of Anesthesia, University Hospital of Geneva, Switzerland
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30
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Higgins TL. Pro: early endotracheal extubation is preferable to late extubation in patients following coronary artery surgery. J Cardiothorac Vasc Anesth 1992; 6:488-93. [PMID: 1498307 DOI: 10.1016/1053-0770(92)90019-4] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Prolonged mechanical ventilation following CABG should not be uncritically considered "routine," and should only be used where indicated. A thorough physiologic and clinical evaluation with attention to hemodynamics, neurologic status, temperature and metabolism, hemostasis, and respiratory reserve should precede extubation. Continued post-operative ventilation is indicated in patients at high risk for complications, and it is possible to identify this subset preoperatively and upon arrival in the postoperative ICU. Early extubation (within 8 hours of arrival) should otherwise be the goal. The benefits of early extubation include improved cardiac function and patient comfort, reduction in respiratory complications, ease in management, and cost savings as the result of shortened length-of-stay in expensive postoperative units. More research is needed to clarify unanswered questions regarding ablating the stress response and avoiding myocardial ischemia.
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Poelaert JI, Reichert CL, Koolen JJ, Everaert JA, Visser CA. Transesophageal Echo-doppler evaluation of the hemodynamic effects of positive-pressure ventilation after coronary artery surgery. J Cardiothorac Vasc Anesth 1992; 6:438-43. [PMID: 1498299 DOI: 10.1016/1053-0770(92)90010-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Transesophageal echocardiography was used to extend knowledge about the impact of positive end-expiratory pressure (PEEP) during mechanical ventilation on right and left ventricular function and right ventricular impedance. At 20 cmH2O PEEP, a progressive increase of right ventricular end-diastolic area was seen (27%) that coincided with a reduction of early left ventricular filling velocity (25%) across the mitral valve, and a decrease of both pulmonary artery flow velocity (end-expiration 27% and end-inspiration 42%) and time-velocity index (end-inspiration 25%). As these changes were not accompanied by a change of the fractional area of contraction, the increase of the right ventricular diameter might be explained by right ventricular compensation due to an imbalance between augmented right ventricular impedance and reduced venous return.
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Affiliation(s)
- J I Poelaert
- Department of Intensive Care, University Hospital Ghent, Belgium
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32
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Biondi JW, Schulman DS, Wiedemann HP, Matthay RA. Mechanical Heart-Lung Interaction in the Adult Respiratory Distress Syndrome. Clin Chest Med 1990. [DOI: 10.1016/s0272-5231(21)00763-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Ekman LG, Abrahamsson J, Biber B, Forssman L, Milsom I, Sjöqvist BA. Hemodynamic changes during laparoscopy with positive end-expiratory pressure ventilation. Acta Anaesthesiol Scand 1988; 32:447-53. [PMID: 2972154 DOI: 10.1111/j.1399-6576.1988.tb02764.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hemodynamic measurements were performed in 10 healthy women undergoing elective laparoscopy for the investigation of infertility. A standardized anesthetic technique which included the application of positive end-expiratory pressure (PEEP), 0.49 kPa (3.7 mmHg) was utilized. The following variables were studied: cardiac output, stroke volume and left ventricular ejection time (determined non-invasively with impedance cardiography), heart rate, blood pressure, total peripheral vascular resistance and end-tidal carbon dioxide (ET-CO2). The combination of 25 degrees head-down tilt and PEEP ventilation during laparoscopy was associated with a pressure response that restored arterial pressures to essentially pre-anesthetic levels. Net cardiac effects were small. With this regime low pressure 0.7-1.1 kPa (5-8 mmHg) intra-abdominal insufflation with CO2 was associated with only minor cardiovascular changes. There were no indications that 0.49 kPa PEEP during laparoscopy produced adverse cardiovascular effects. The application of PEEP reduced (P less than 0.001) ET-CO2. There was no net increase in ET-CO2 after CO2-insufflation compared to the measurement after induction of anesthesia. This is in contrast to earlier studies without PEEP where a significant net increase in ET-CO2 was reported after CO2-insufflation.
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Affiliation(s)
- L G Ekman
- Department of Obstetrics and Gynecology, University of Göteborg, East Hospital, Sweden
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34
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Hurford WE, Zapol WM. The right ventricle and critical illness: a review of anatomy, physiology, and clinical evaluation of its function. Intensive Care Med 1988; 14 Suppl 2:448-57. [PMID: 3042829 DOI: 10.1007/bf00256958] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This paper reviews right ventricular anatomy and physiology in the critically ill patient. The role of right ventricular function during acute pulmonary artery hypertension and the effect of acute myocardial injury upon right ventricular performance are examined. Clinical methods of assessing right ventricular function at the bedside in acutely ill patients are critically reviewed.
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Affiliation(s)
- W E Hurford
- Department of Anesthesia, Massachusetts General Hospital, Boston
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35
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Neidhart PP, Suter PM. Changes of right ventricular function with positive end-expiratory pressure (PEEP) in man. Intensive Care Med 1988; 14 Suppl 2:471-3. [PMID: 3042830 DOI: 10.1007/bf00256962] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The side effects of positive pressure ventilation on cardiovascular function are well known. However, in most clinical studies its influence on left ventricular function was examined. In the present study right ventricular (RV) performance was studied in 13 patients undergoing coronary artery bypass grafting during mechanical ventilation with and without positive end-expiratory pressure (PEEP). In the majority of patients (10/13), PEEP caused a decrease in RV end-diastolic volume (by 18%) whereas RV ejection fraction did not change. In the remaining 3 patients, end-diastolic and end-systolic RV volumes increased by 25% and 50% respectively and ejection fraction decreased by 29%. These results suggest that PEEP can affect RV function in two different ways: first, in the majority of patients studied, PEEP exerted an unloading effect on the RV whereas second, in 3 patients RV dilatation and a decrease in ejection fraction was observed.
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Affiliation(s)
- P P Neidhart
- Department of Anesthesia and Surgical Intensive Care, University Hospital of Geneva, Switzerland
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36
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Biondi JW, Schulman DS, Matthay RA. Effects of Mechanical Ventilation on Right and Left Ventricular Function. Clin Chest Med 1988. [DOI: 10.1016/s0272-5231(21)00485-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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