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Campos MD, Bonardi A, Palazzi LH, Madorno M, Böhm SH, Tusman G. Development of a Novel Infant Volumetric Capnography Simulator: Making the Invisible Visible Improves Understanding and Safety. Simul Healthc 2024; 19:254-262. [PMID: 36877685 DOI: 10.1097/sih.0000000000000717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
INTRODUCTION Volumetric capnography depicts volumetric capnograms [ie, the plot of expired carbon dioxide (CO 2 ) over the tidal volume]. This bench study aimed to determine the reliability, accuracy, and precision of a novel infant simulator for volumetric capnography. This simulator would be clinically valuable for teaching purposes because it reflects the entire cardiopulmonary physiology within 1 breath. METHODS An infant lung simulator was fed with CO 2 supplied by a mass flow controller (VCO 2-IN ) and ventilated using standard settings. A volumetric capnograph was placed between the endotracheal tube and the ventilatory circuit. We simulated ventilated babies of different body weights (2, 2.5, 3, and 5 kg) with a VCO 2 ranging from 12 to 30 mL/min. The correlation coefficient ( r2 ), bias, coefficient of variation (CV = SD/ x × 100), and precision (2 × CV) between the VCO 2-IN and the elimination of CO 2 recorded by the capnograph (VCO 2-OUT ) were calculated. The quality of the capnogram's waveforms was compared with real ones belonging to anesthetized infants using an 8-point scoring system, where 6 points or greater meant that the simulated capnogram showed good, 5 to 3 points acceptable, and less than 3 points an unacceptable shape. RESULTS The correlation between VCO 2-IN and VCO 2-OUT was r2 = 0.9953 ( P < 0.001), with a bias of 0.16 (95% confidence intervals from 0.12 to 0.20) mL/min. The CV was 5% or less and the precision was 10% or less. All simulated capnograms showed similar shapes compared with real babies, scoring 6 points for 3 kg and 6.5 points for 2-, 2.5-, and 5-kg babies. CONCLUSIONS The simulator of volumetric capnograms was reliable, accurate, and precise for simulating the CO 2 kinetics of ventilated infants.
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Affiliation(s)
- Marcelo D Campos
- From the Department of Anesthesiology (M.D.C.), Sanatorio Finochietto, Buenos Aires, Argentina; Simulation Center of Buenos Aires Association of Anesthesia (A.B.), Analgesia y Reanimation, Buenos Aires, Argentina; Department of Anesthesiology (L.H.P.), Children Hospital Dr. Orlando Alassia, Santa Fe, Argentina; Instituto Tecnológico Buenos Aires (ITBA) (M.M.), Buenos Aires, Argentina; Department of Anesthesiology and Intensive Care Medicine (S.H.B.), Rostock University Medical Center, Rostock, Germany; and Department of Anesthesia (G.T.), Hospital Privado de Comunidad, Mar del Plata, Argentina
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Zuiki M, Hasegawa T, Ohshimo S, Iehara T, Shime N. The Usefulness of Continuous Respiratory Sound Monitoring for the Detection of Pulmonary Atelectasis in a Ventilated Extremely Low Birth Weight Infant. Cureus 2024; 16:e65394. [PMID: 39184734 PMCID: PMC11344869 DOI: 10.7759/cureus.65394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2024] [Indexed: 08/27/2024] Open
Abstract
The assessment of auscultation using a stethoscope is unsuitable for continuous monitoring. Therefore, we developed a novel acoustic monitoring system that continuously, objectively, and visually evaluates respiratory sounds. In this report, we assess the usefulness of our revised system in a ventilated extremely low birth weight infant (ELBWI) for the diagnosis of pulmonary atelectasis and evaluation of treatment by lung lavage. A female infant was born at 24 weeks of age with a birth weight of 636 g after emergency cesarean section. The patient received invasive mechanical ventilation immediately after birth in our neonatal (NICU). After obtaining informed consent, we monitored her respiratory status using the respiratory-sound monitoring system by attaching a sound collection sensor to the right anterior chest wall. On day 26, lung-sound spectrograms showed that the breath sounds were attenuated simultaneously as hypoxemia progressed. Finally, chest radiography confirmed the diagnosis as pulmonary atelectasis. To relieve atelectasis, surfactant lavage was performed, after which the lung-sound spectrograms returned to normal. Hypoxemia and chest radiographic findings improved significantly. On day 138, the patient was discharged from the NICU without complications. The continuous respiratory-sound monitoring system enabled the visual, quantitative, and noninvasive detection of acute regional lung abnormalities at the bedside. We, therefore, believe that this system can resolve several problems associated with neonatal respiratory management and save lives.
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Affiliation(s)
- Masashi Zuiki
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, JPN
| | - Tatsuji Hasegawa
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, JPN
| | - Shinichiro Ohshimo
- Department of Emergency and Critical Care Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, JPN
| | - Tomoko Iehara
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, JPN
| | - Nobuaki Shime
- Department of Emergency and Critical Care Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, JPN
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Hartmann K, Calatayud B, Flamm A. Prehospital Use of Waveform Capnography in Intubated Neonates. PREHOSP EMERG CARE 2024; 28:568-571. [PMID: 38261425 DOI: 10.1080/10903127.2024.2309214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 12/06/2023] [Indexed: 01/25/2024]
Abstract
INTRODUCTION Routine continuous monitoring of endotracheal tube placement with waveform capnography is considered standard of care in the prehospital setting. However, maintaining this standard in neonatal patients remains a challenge due to low tidal volumes that do not tolerate the additional dead space ETCO2 attachments add. Additionally, continuous ETCO2 can increase the risk of ETT dislodgement or kinking because of the weight and size of the capnography attachments relative to the patient and tube size. We hypothesize that there is a gap in care of intubated neonates when compared to adults in the prehospital setting in terms of continuous monitoring of ETT placement. METHODS Data were obtained from a single air medical agency. Through a retrospective chart review, records of intubated neonates (<28 days), children (≥28 days-12 years), adolescents (13-18 years), and adults (aged ≥18 years) were analyzed. Records were available from 11/21/13-1/21/22. The number of intubation attempts, whether an intubation was successful, and the use of capnography were recorded in RedCap. Statistical analysis was performed in Microsoft Excel via Chi Square Goodness of Fit Tests. RESULTS During the study period, 674 intubation attempts were identified, and 28 charts were excluded due to missing patient age. Continuous waveform ETCO2 monitoring was used on 62%, 94%, 95%, and 97% of successfully intubated neonates, children, adolescents, and adults, respectively. There was a statistically significant difference between use of continuous waveform capnography in adults and neonates (p-value = 0.013). There was also a statistically significant difference between use of continuous waveform capnography in intubated neonates, children, and adolescents (p-value = 0.049). CONCLUSION Continuous ETCO2 monitoring is underutilized in intubated neonates compared to children, adolescents, and adults in the prehospital setting in this study population. This suggests a gap in the standard of care provided to neonates. Additional studies are needed to determine if these results are consistent around the industry and if there is a higher rate of undetected tube displacement in neonates who are transported without waveform capnography.
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Affiliation(s)
| | | | - Avram Flamm
- Penn State College of Medicine, Hershey, Pennsylvania
- Department of Emergency Medicine, WellSpan Health, York, Pennsylvania
- WellSpan EMS, York, Pennsylvania
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Damam S, Meshram RJ, Taksande A, Lohiya S, Khurana A, Patel A, Khandelwal R, Nath R, Javvaji CK, Kakkat S. Navigating Pediatric Capnography: A Comprehensive Review of Scope and Limitations. Cureus 2024; 16:e53289. [PMID: 38435961 PMCID: PMC10905056 DOI: 10.7759/cureus.53289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 01/31/2024] [Indexed: 03/05/2024] Open
Abstract
This review comprehensively explores pediatric capnography, a vital tool in contemporary respiratory monitoring. The overview encompasses the foundational principles of capnography, elucidating its real-time measurement of carbon dioxide (CO2) in respiratory gases. The review emphasizes its paramount role in pediatric care and underscores capnography's significance in detecting respiratory abnormalities and guiding timely interventions. The distinctions between mainstream and sidestream capnography, the key to understanding their applications, are meticulously outlined. Addressing the importance of ongoing research and education, the review advocates for a dynamic approach to refine guidelines and optimize capnography utilization in pediatric settings. The conclusion reflects on the scope and limitations of pediatric capnography, acknowledging its transformative impact while advocating for a judicious recognition of constraints. As we navigate the future of pediatric respiratory care, the synergy of research, education, and clinical application emerges as the cornerstone for advancing pediatric capnography to new horizons.
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Affiliation(s)
- SreeHarsha Damam
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Revat J Meshram
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Amar Taksande
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Sham Lohiya
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Astha Khurana
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Ankita Patel
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Rahul Khandelwal
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Ritwik Nath
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Chaitanya Kumar Javvaji
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Shikha Kakkat
- Pediatrics, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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Campos MD, Palazzi LH, Böhm SH, Tusman G. Effects of apparatus dead space on volumetric capnograms in neonates with healthy lungs: a simulation study. Paediatr Anaesth 2023; 33:973-982. [PMID: 37403466 DOI: 10.1111/pan.14724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/19/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023]
Abstract
BACKGROUND Volumetric capnography in healthy ventilated neonates showed deformed waveforms, which are supposedly due to technological limitations of flow and carbon dioxide sensors. AIMS This bench study analyzed the role of apparatus dead space on the shape of capnograms in simulated neonates with healthy lungs. METHODS We simulated mechanical breaths in neonates of 2, 2.5, and 3 kg of body weight using a neonatal volumetric capnography simulator. The simulator was fed by a fixed amount of carbon dioxide of 6 mL/kg/min. Such simulator was ventilated in a volume control mode using fixed ventilatory settings with a tidal volume of 8 mL/kg and respiratory rates of 40, 35, and 30 breaths per minute for the 2, 2.5 and 3 kg neonates, respectively. We tested the above baseline ventilation with and without an additional apparatus dead space of 4 mL. RESULTS Simulations showed that adding the apparatus dead space to baseline ventilation increased the amount of re-inhaled carbon dioxide in all neonates: 0.16 ± 0.01 to 0.32 ± 0.03 mL (2 kg), 0.14 ± 0.02 to 0.39 ± 0.05 mL (2.5 kg), and 0.13 ± 0.01 to 0.36 ± 0.05 mL (3 kg); (p < .001). Apparatus dead space was computed as part of the airway dead space, and therefore, the ratio of airway dead space to tidal volume increased from 0.51 ± 0.04 to 0.68 ± 0.06, from 0.43 ± 0.04 to 0.62 ± 0.01 and from 0.38 ± 0.01 to 0.60 ± 0.02 in the 2, 2.5 and 3 kg simulated neonates, respectively (p < .001). Compared to baseline ventilation, adding apparatus dead space decreased the ratio of the volume of phase III to VT size from 31% to 11% (2 kg), from 40% to 16% (2.5 kg) and from 50% to 18% (3 kg); (p < .001). CONCLUSIONS The addition of a small apparatus dead space artificially deformed the volumetric capnograms in simulated neonates with healthy lungs.
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Affiliation(s)
- Marcelo D Campos
- Department of Anesthesiology, Sanatorio Finochietto, Buenos Aires, Argentina
| | - Lucio H Palazzi
- Department of Anesthesiology, Children Hospital Dr. Orlando Alassia, Santa Fe, Argentina
| | - Stephan H Böhm
- Clinic of Anesthesiology, Intensive Care Medicine and Pain Therapy, Rostock University Medical Center, Rostock, Germany
| | - Gerardo Tusman
- Department of Anesthesia, Hospital Privado de Comunidad, Mar del Plata, Argentina
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Williams EE, Gareth Jones J, McCurnin D, Rüdiger M, Nanjundappa M, Greenough A, Dassios T. Functional morphometry: non-invasive estimation of the alveolar surface area in extremely preterm infants. Pediatr Res 2023; 94:1707-1713. [PMID: 37045946 PMCID: PMC10624622 DOI: 10.1038/s41390-023-02597-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/14/2023]
Abstract
BACKGROUND The main pathophysiologic characteristic of chronic respiratory disease following extremely premature birth is arrested alveolar growth, which translates to a smaller alveolar surface area (SA). We aimed to use non-invasive measurements to estimate the SA in extremely preterm infants. METHODS Paired measurements of the fraction of inspired oxygen and transcutaneous oxygen saturation were used to calculate the ventilation/perfusion ratio, which was translated to SA using Fick's law of diffusion. The SA was then adjusted using volumetric capnography. RESULTS Thirty infants with a median (range) gestational age of 26.3 (22.9-27.9) weeks were studied. The median (range) adjusted SA was 647.9 (316.4-902.7) cm2. The adjusted SA was lower in the infants who required home oxygen [637.7 (323.5-837.5) cm2] compared to those who did not [799.1 (444.2-902.7) cm2, p = 0.016]. In predicting the need for supplemental home oxygen, the adjusted SA had an area under the receiver operator characteristic curve of 0.815 (p = 0.017). An adjusted SA ≥688.6 cm2 had 86% sensitivity and 77% specificity in predicting the need for supplemental home oxygen. CONCLUSIONS The alveolar surface area can be estimated non-invasively in extremely preterm infants. The adjusted alveolar surface area has the potential to predict the subsequent need for discharge home on supplemental oxygen. IMPACT We describe a novel biomarker of respiratory disease following extremely preterm birth. The adjusted alveolar surface area index was derived by non-invasive measurements of the ventilation/perfusion ratio and adjusted by concurrent measurements of volumetric capnography. The adjusted alveolar surface area was markedly reduced in extremely preterm infants studied at 7 days of life and could predict the need for discharge home on supplemental oxygen. This method could be used at the bedside to estimate the alveolar surface area and provide an index of the severity of lung disease, and assist in monitoring, clinical management and prognosis.
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Affiliation(s)
- Emma E Williams
- Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - J Gareth Jones
- Cambridge University Clinical School, Hills Rd, Cambridge, UK
| | - Donald McCurnin
- Division of Neonatology, Department of Pediatrics, University of Texas Health, San Antonio, TX, USA
| | - Mario Rüdiger
- Neonatology and Pediatric Critical Care Medicine, Department of Pediatrics, Medizinische Fakultät, Carl Gustav Carus, TU Dresden, Dresden, Germany
- Saxony Center for Feto/Neonatal Health, Medizinische Fakultät, TU Dresden, Dresden, Germany
| | - Mahesh Nanjundappa
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Anne Greenough
- Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Theodore Dassios
- Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK.
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Dassios T, Kaltsogianni O, Saka J, Greenough A. A neonatal in-vitro study on the effect of the inflation pressure on end-tidal carbon dioxide levels. Med Eng Phys 2023; 120:104052. [PMID: 37838403 DOI: 10.1016/j.medengphy.2023.104052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/05/2023] [Accepted: 09/11/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Describing the association of the peak inflation pressure (PIP) with end-tidal carbon dioxide (ETCO2) is a prerequisite for the development of closed loop ventilation in neonatal intensive care. We aimed to develop an in-vitro system to study this relationship. METHODS A ventilator was connected to a test lung, supplied with a stable CO2 concentration from a cylinder. The PIP was altered and the change in ETCO2 per unit of PIP was calculated in three models mimicking respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD) and viral bronchiolitis. RESULTS The median (IQR) change in ETCO2 per unit of PIP was 0.23(0.13-0.38) kPa/cmH2O, using 138 paired measurements of PIP and ETCO2. The median (IQR) change in ETCO2 per unit of PIP, was higher when starting at an ETCO2 > 6 kPa [0.43(0.33-0.58) kPa/cmH2O] compared to starting at an ETCO2 < 6 kPa [0.14(0.08-0.20) kPa/cmH2O, p < 0.001]. The median (IQR) change in ETCO2 per unit of PIP, was larger in the model of RDS [0.33(0.13-0.51) kPa/cmH2O] compared to the BPD [0.23(0.13-0.33) kPa/cmH2O, p = 0.043] and the bronchiolitis models [0.15(0.10-0.31) kPa/cmH2O, p = 0.017]. CONCLUSIONS The change in ETCO2 in response to increasing PIP was larger for higher ETCO2 values and in a model simulating neonatal RDS, compared to BPD and bronchiolitis.
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Affiliation(s)
- Theodore Dassios
- Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, United Kingdom.
| | - Ourania Kaltsogianni
- Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Jonathan Saka
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Anne Greenough
- Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
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Vallarino M, Quintela L, Jorge G, Lorenzo G, Nan C, Isper M, Bouchacourt JP, Grignola JC. SAMAY S24: a novel wireless 'online' device for real-time monitoring and analysis of volumetric capnography. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083576 DOI: 10.1109/embc40787.2023.10340680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Volumetric capnography (VCap) provides information about CO2 exhaled per breath (VCO2br) and physiologic dead space (VDphys). A novel wireless device with a high response time CO2 mainstream sensor coupled with a digital flowmeter was designed to monitor all VCap parameters online in rabbits (SAMAY S24).Ten New Zealand rabbits were anesthetized and mechanically ventilated. VCO2br corresponds to the area under the VCap curve. We used the modified Langley method to assess the airway VD (VDaw) and the alveolar CO2 pressure. VDphys was estimated using Bohr's formula, and the alveolar VD was calculated by subtracting VDaw from VDphys. We compared (Bland-Altman) the critical VCap parameters obtained by SAMAY S24 (Langley) with the Functional Approximation based on the Levenberg-Marquardt Algorithm (FA-LMA) approach during closed and opened chest conditions.SAMAY S24 could assess dead space volumes and VCap shape in real time with similar accuracy and precision compared to the 'offline' FA-LMA approach. The opened chest condition impaired CO2 kinetics, decreasing the phase II slope, which was correlated with the volume of CO2 exhaled per minute.
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Fucikova H, Blatny J, Stingl J, Miletin J. Capnometry during neonatal transport-Mini review. Acta Paediatr 2023; 112:919-923. [PMID: 36843232 DOI: 10.1111/apa.16729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/15/2023] [Accepted: 02/23/2023] [Indexed: 02/28/2023]
Abstract
AIM The aim of this review was to give an overview of available data on end-tidal CO2 (etCO2 ) monitoring, also called capnometry, during neonatal transport. METHODS Pubmed/MEDLINE database was searched using research question (capno* OR etCO2 OR detCO2 OR (['end tidal' OR 'end-tidal'] AND [CO2 OR 'carbon dioxide']) AND (neonat* OR infant* OR newborn*) AND transport*). All articles relevant to the topic were reviewed and summarised. RESULTS The lack of studies relevant to neonatal transport prompted us to extend the search to capnometry in a neonatal intensive care setting. The published studies are showing conflicting results. The different study populations, technologies used to measure etCO2 , types of etCO2 sampling and the diverse sites of blood gas tests make the data unsuitable for systematic comparison. CONCLUSION Further research to obtain more data on capnometry during neonatal transport will be necessary to define precisely under what circumstances can end-tidal monitoring of CO2 be reliably used in neonates during transport and also how to interpret the measured values.
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Affiliation(s)
- Hana Fucikova
- Coombe Women and Infants University Hospital, Dublin, Ireland
- Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jan Blatny
- Faculty of Medicine, Masaryk University, Brno, Czech Republic
- Children's University Hospital, Brno, Czech Republic
| | - Jan Stingl
- Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jan Miletin
- Coombe Women and Infants University Hospital, Dublin, Ireland
- Institute for the Care of Mother and Child, Prague, Czech Republic
- UCD School of Medicine, University College Dublin, Dublin, Ireland
- Second Faculty of Medicine, Charles University, Prague, Czech Republic
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Karlsson J, Lönnqvist PA. Capnodynamics - noninvasive cardiac output and mixed venous oxygen saturation monitoring in children. Front Pediatr 2023; 11:1111270. [PMID: 36816378 PMCID: PMC9936087 DOI: 10.3389/fped.2023.1111270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Hemodynamic monitoring in children is challenging for many reasons. Technical limitations in combination with insufficient validation against reference methods, makes reliable monitoring systems difficult to establish. Since recent studies have highlighted perioperative cardiovascular stability as an important factor for patient outcome in pediatrics, the need for accurate hemodynamic monitoring methods in children is obvious. The development of mathematical processing of fast response mainstream capnography signals, has allowed for the development of capnodynamic hemodynamic monitoring. By inducing small changes in ventilation in intubated and mechanically ventilated patients, fluctuations in alveolar carbon dioxide are created. The subsequent changes in carbon dioxide elimination can be used to calculate the blood flow participating in gas exchange, i.e., effective pulmonary blood flow which equals the non-shunted pulmonary blood flow. Cardiac output can then be estimated and continuously monitored in a breath-by-breath fashion without the need for additional equipment, training, or calibration. In addition, the method allows for mixed venous oxygen saturation (SvO2) monitoring, without pulmonary artery catheterization. The current review will discuss the capnodyamic method and its application and limitation as well as future potential development and functions in pediatric patients.
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Affiliation(s)
- Jacob Karlsson
- Dept of Physiology & Pharmacology, Section of Anaesthesiology and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.,Paediatric Perioperative Medicine & Intensive Care, Karolinska University Hospital, Stockholm, Sweden
| | - Per-Arne Lönnqvist
- Dept of Physiology & Pharmacology, Section of Anaesthesiology and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.,Paediatric Perioperative Medicine & Intensive Care, Karolinska University Hospital, Stockholm, Sweden
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Coleman J, Ginsburg AS, Macharia WM, Ochieng R, Chomba D, Zhou G, Dunsmuir D, Karlen W, Ansermino JM. Assessment of neonatal respiratory rate variability. J Clin Monit Comput 2022; 36:1869-1879. [PMID: 35332406 PMCID: PMC9637627 DOI: 10.1007/s10877-022-00840-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 03/02/2022] [Indexed: 11/30/2022]
Abstract
Accurate measurement of respiratory rate (RR) in neonates is challenging due to high neonatal RR variability (RRV). There is growing evidence that RRV measurement could inform and guide neonatal care. We sought to quantify neonatal RRV during a clinical study in which we compared multiparameter continuous physiological monitoring (MCPM) devices. Measurements of capnography-recorded exhaled carbon dioxide across 60-s epochs were collected from neonates admitted to the neonatal unit at Aga Khan University-Nairobi hospital. Breaths were manually counted from capnograms and using an automated signal detection algorithm which also calculated mean and median RR for each epoch. Outcome measures were between- and within-neonate RRV, between- and within-epoch RRV, and 95% limits of agreement, bias, and root-mean-square deviation. Twenty-seven neonates were included, with 130 epochs analysed. Mean manual breath count (MBC) was 48 breaths per minute. Median RRV ranged from 11.5% (interquartile range (IQR) 6.8-18.9%) to 28.1% (IQR 23.5-36.7%). Bias and limits of agreement for MBC vs algorithm-derived breath count, MBC vs algorithm-derived median breath rate, MBC vs algorithm-derived mean breath rate were - 0.5 (- 2.7, 1.66), - 3.16 (- 12.12, 5.8), and - 3.99 (- 11.3, 3.32), respectively. The marked RRV highlights the challenge of performing accurate RR measurements in neonates. More research is required to optimize the use of RRV to improve care. When evaluating MCPM devices, accuracy thresholds should be less stringent in newborns due to increased RRV. Lastly, median RR, which discounts the impact of extreme outliers, may be more reflective of the underlying physiological control of breathing.
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Affiliation(s)
- Jesse Coleman
- Evaluation of Technologies for Neonates in Africa (ETNA), Nairobi, Kenya.
- Centre for International Child Health, 305 - 4088 Cambie Street, Vancouver, BC, V5Z 2X8, Canada.
| | | | | | | | - Dorothy Chomba
- Department of Pediatrics, Aga Khan University, Nairobi, Kenya
| | - Guohai Zhou
- Center for Clinical Investigation, Brigham and Women's Hospital, Boston, MA, USA
| | - Dustin Dunsmuir
- Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, Vancouver, BC, Canada
| | - Walter Karlen
- Mobile Health Systems Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - J Mark Ansermino
- Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, Vancouver, BC, Canada
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Capnography in newborns under mechanical ventilation and its relationship with the measurement of CO 2 in blood samples. An Pediatr (Barc) 2022; 97:255-261. [PMID: 36109326 DOI: 10.1016/j.anpede.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/15/2022] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION Monitoring the partial pressure of CO2 (PCO2) in newborns who require ventilation would allow avoiding hypocapnia and hypercapnia. The measurement of end-tidal carbon dioxide (ETCO2) is an alternative rarely implemented in this population. OBJECTIVE To evaluate the relationship between ETCO2 and PCO2 in newborns. METHODS Cross-sectional study comparing two PCO2 measurement methods, the conventional one by analysis of blood samples and the one estimated by ETCO2. The study included hospitalized newborns that required conventional mechanical ventilation. The ETCO2 was measured with a Tecme GraphNet® neo, a neonatal ventilator with an integrated capnograph, and we obtained the ETCO2-PCO2 gradient. We conducted correlation and Bland-Altman plot analyses to estimate the agreement. RESULTS A total of 277 samples (ETCO2 / PCO2) from 83 newborns were analyzed. The mean values of ETCO2 and PCO2 were 41.36mmHg and 42.04mmHg. There was a positive and significant correlation between ETCO2 and PCO2 in the overall analysis (r=0.5402; P<.001) and in the analysis of each unit (P<.001). The mean difference was 0.68 mmHg (95% CI, -0.68 to 1.95) and was not significant. We observed a positive systematic error (PCO2 > ETCO2) in 2 of the units, and a negative difference in the third (PCO2 < ETCO2). DISCUSSION The correlation between ETCO and PCO2 was significant, although the obtained values were not equivalent, with differences ranging from 0.1mmHg and 20mmHg. Likewise, we found systematic errors that differed in sign (positive or negative) between institutions.
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13
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Werther T, Aichhorn L, Stellberg S, Cardona FS, Klebermass-Schrehof K, Berger A, Schmölzer GM, Wagner M. Monitoring of carbon dioxide in ventilated neonates: a prospective observational study. Arch Dis Child Fetal Neonatal Ed 2022; 107:293-298. [PMID: 34344835 DOI: 10.1136/archdischild-2021-322138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/19/2021] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To assess the reliability, accuracy and precision of distal end-tidal capnography (detCO2) in neonates compared with transcutaneous (tcCO2) carbon dioxide measurements. DESIGN Observational, prospective clinical study. SETTING Neonatal intensive care unit at Medical University of Vienna. PARTICIPANTS Conventionally ventilated neonates with a body weight between 1000 g and 3000 g. INTERVENTION End-tidal partial pressure of CO2 was measured in distal position using the separate lumen of a double-lumen endotracheal tube connected to an external side-stream capnometer. Three consecutive detCO2 and tcCO2 values were recorded simultaneously and compared with simultaneous arterialised partial pressure of CO2 (paCO2) measurements in each patient. MAIN OUTCOME MEASURES Reliability, accuracy and precision of detCO2 and tcCO2 measurements compared with paCO2 in neonates. RESULTS Twenty-five neonates were included with a median (range) weight at enrolment of 1410 (1010-2980) g, from which 81 simultaneous measurements of detCO2, tcCO2 and paCO2 were obtained. The mean (SD) of paCO2, detCO2 and tcCO2 was 45.0 (8.6) mmHg, 42.4 (8.4) mmHg and 50.4 (20.4) mmHg, respectively. The intraclass correlation between paCO2 and detCO2 and between paCO2 and tcCO2 reached 0.80 (95% CI 0.71 to 0.87, p<0.001) and 0.59 (95% CI 0.43 to 0.72, p<0.001), respectively. In the Bland-Altman analysis, bias and precision of detCO2 with respect to paCO2 amounted to -2.68 mmHg and 10.62 mmHg (95% CI 8.49 to 14.51), respectively. Bias and precision of tcCO2 with respect to paCO2 amounted to 5.39 mmHg and 17.22 mmHg (95% CI 13.21 to 23.34), respectively. CONCLUSION DetCO2 had better reliability, accuracy and precision with paCO2 than tcCO2 in ventilated neonates without severe lung diseas. TRIAL REGISTRATION NUMBER NCT03758313.
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Affiliation(s)
- Tobias Werther
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Lukas Aichhorn
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Sina Stellberg
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Francesco Stefano Cardona
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Katrin Klebermass-Schrehof
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Angelika Berger
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Georg M Schmölzer
- Department of Pediatrics, Division of Neonatology, University of Alberta, Edmonton, Alberta, Canada.,Centre for the Studies of Asphyxia and Resuscitation, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Wagner
- Department of Pediatrics, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Comprehensive Center for Pediatrics, Medical University of Vienna, Vienna, Austria
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Sosa I, Cardetti M, Favareto V, Maure C, Ceballos E, Abona H, Martínez F, Gigli M, Rodríguez S, Sola A. Capnografía en recién nacidos en ventilación mecánica y su relación con la medición de CO2 en muestras sanguíneas. An Pediatr (Barc) 2022. [DOI: 10.1016/j.anpedi.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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15
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Ardura-Garcia C, Abellan A, Cuevas-Ocaña S, Freitag N, Lam YT, Makrinioti H, Slaats M, Storti M, Williams EE, Dassios T, Duijts L, Ersu RH, Fustik S, Morty RE, Proesmans M, Schramm D, Saglani S, Moeller A, Pijnenburg MW. ERS International Congress 2021: highlights from the Paediatric Assembly. ERJ Open Res 2022; 8:00643-2021. [PMID: 35615416 PMCID: PMC9125040 DOI: 10.1183/23120541.00643-2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/02/2022] [Indexed: 11/26/2022] Open
Abstract
In this review, Early Career Members of the European Respiratory Society (ERS) and the Chairs of the ERS Assembly 7: Paediatrics present the highlights in paediatric respiratory medicine from the ERS International Congress 2021. The eight scientific Groups of this Assembly cover respiratory physiology and sleep, asthma and allergy, cystic fibrosis (CF), respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology, bronchology, and lung and airway development. We here describe new developments in lung function testing and sleep-disordered breathing diagnosis, early life exposures affecting pulmonary function in children and effect of COVID-19 on sleep and lung function. In paediatric asthma, we present the important role of the exposome in asthma development, and how biologics can provide better outcomes. We discuss new methods to assess distal airways in children with CF, as some details remain blind when using the lung clearance index. Moreover, we summarise the new ERS guidelines for bronchiectasis management in children and adolescents. We present interventions to reduce morbidity and monitor pulmonary function in newborns at risk of bronchopulmonary dysplasia and long-term chronic respiratory morbidity of this disease. In respiratory epidemiology, we characterise primary ciliary dyskinesia, identify early life determinants of respiratory health and describe the effect of COVID-19 preventive measures on respiratory symptoms. Also, we describe the epidemiology of interstitial lung diseases, possible consequences of tracheomalacia and a classification of diffuse alveolar haemorrhage in children. Finally, we highlight that the characterisation of genes and pathways involved in the development of a disease is essential to identify new biomarkers and therapeutic targets.
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Affiliation(s)
| | - Alicia Abellan
- ISGlobal, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
- Fundació Institut Universitari per a la Recerca a l'Atenció Primària de Salut Jordi Gol i Gurina, Barcelona, Spain
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Sara Cuevas-Ocaña
- Nottingham Biodiscovery Institute, School of Medicine, University of Nottingham, Nottingham, UK
| | - Nadine Freitag
- Dept of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Yin Ting Lam
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Heidi Makrinioti
- West Middlesex University Hospital, Chelsea and Westminster Foundation Trust, London, UK
| | - Monique Slaats
- Dept of Paediatrics, Division of Paediatric Respiratory Medicine and Allergology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Matteo Storti
- Dept of Chemical and Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Emma E. Williams
- Dept of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Theodore Dassios
- Dept of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Liesbeth Duijts
- Dept of Paediatrics, Division of Paediatric Respiratory Medicine and Allergology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands
- Division of Neonatology, Dept of Pediatrics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Refika H. Ersu
- Division of Respirology, University of Ottawa Children's Hospital of Eastern Ontario, Ottawa, Canada
| | - Stojka Fustik
- University Children's Hospital, Skopje, North Macedonia
| | - Rory E. Morty
- Dept of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
- Dept of Translational Pulmonology and the Translational Lung Research Center Heidelberg, University Hospital Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Marijke Proesmans
- Division Woman and Child, Dept of Paediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Dirk Schramm
- Dept of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sejal Saglani
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Alexander Moeller
- Division of Paediatric Pulmonology, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Marielle W. Pijnenburg
- Dept of Paediatrics, Division of Paediatric Respiratory Medicine and Allergology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands
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16
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Karlsson J, Lönnqvist PA. Capnodynamics-Measuring cardiac output via ventilation. Paediatr Anaesth 2022; 32:255-261. [PMID: 34758163 DOI: 10.1111/pan.14329] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/21/2021] [Accepted: 11/03/2021] [Indexed: 12/12/2022]
Abstract
Recent studies have identified stable hemodynamics as a contributing factor to improve outcome in pediatric anesthesia. So far, most of the hemodynamic monitoring methods applied in children have been complex to apply and often not satisfactory validated. Standard mainstream carbon dioxide analysis in combination with real-time mathematical analysis of the measured capnography data has enabled the development of dynamic capnography, a non-invasively cardiac output monitoring method that can be applied without user practice or need for calibrations. Capnodynamic cardiac output assessment has been extensively validated against gold standard reference methods, both in experimental and clinical settings. This review will describe the principle behind dynamic capnography measurement of cardiac output and mixed venous oxygen saturation. Additionally, the methods limitations and challenges when applied in children will be delineated.
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Affiliation(s)
- Jacob Karlsson
- Department of Physiology and Pharmacology (FYFA), C3, Per-Arne Lönnqvist Group-Section of Anesthesiology and Intensive Care, Karolinska Institute, Stockholm, Sweden.,Pediatric perioperative medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
| | - Per-Arne Lönnqvist
- Department of Physiology and Pharmacology (FYFA), C3, Per-Arne Lönnqvist 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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17
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Fouzas S, Kentgens AC, Lagiou O, Frauchiger BS, Wyler F, Theodorakopoulos I, Yammine S, Latzin P. Novel volumetric capnography indices measure ventilation inhomogeneity in cystic fibrosis. ERJ Open Res 2022; 8:00440-2021. [PMID: 35295235 PMCID: PMC8918935 DOI: 10.1183/23120541.00440-2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 12/14/2021] [Indexed: 11/05/2022] Open
Abstract
BackgroundVolumetric capnography (VCap) is a simpler alternative of multiple-breath washout (MBW) to detect ventilation inhomogeneity (VI) in patients with cystic fibrosis (CF). However, its diagnostic performance is influenced by breathing dynamics. We introduce two novel VCap indices, the Capnographic Inhomogeneity Indices (CIIs) that may overcome this limitation and explore their diagnostic characteristics in a cohort of CF patients.MethodsWe analysed 320 N2-MBW trials from 50 CF patients and 65 controls (age 4-18 years) and calculated classical VCap indices, such as slope III (SIII) and the capnographic index (KPIv). We introduced novel CIIs based on a theoretical lung model, and assessed their diagnostic performance compared to classical VCap indices and the lung clearance index (LCI).ResultsBoth CIIs were significantly higher in CF patients compared with controls (mean±SD CII1 5.9±1.4% versus 5.1±1.0%, p=0.002; CII2 7.7±1.8% versus 6.8±1.4%, p=0.002) and presented strong correlation with LCI (CII1 R2=0.47 and CII2 R2=0.44 in CF patients). Classical VCap indices showed inferior discriminative ability (SIII 2.3±1.0%/L versus 1.9±0.7%/L, P=0.013; KPIv 3.9±1.3% versus 3.5±1.2%, P=0.071), while the correlation with LCI was weak (SIII R2=0.03; KPIv R2=0.08 in CF patients). CIIs showed lower intra-subject inter-trial variability, calculated as coefficient of variation for three and relative difference for two trials, than classical VCap indices, but higher than LCI (CII1 11.1±8.2% and CII2 11.0±8.0% versus SIII 16.3±13.5%; KPIv 15.9±12.8%; LCI 5.9%±4.2%).ConclusionCIIs detect VI better than classical VCap indices and correlate well with LCI. However, further studies on their diagnostic performance and clinical utility are required.
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18
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Volumetric capnography pre- and post-surfactant during initial resuscitation of premature infants. Pediatr Res 2022; 91:1551-1556. [PMID: 34023855 PMCID: PMC9197760 DOI: 10.1038/s41390-021-01578-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Volumetric capnography allows for continuous monitoring of expired tidal volume and carbon dioxide. The slope of the alveolar plateau of the capnogram (SIII) could provide information regarding ventilation homogeneity. We aimed to assess the feasibility of measuring SIII during newborn resuscitation and determine if SIII decreased after surfactant indicating ventilation inhomogeneity improvement. METHODS Respiratory function traces of preterm infants resuscitated at birth were analysed. Ten capnograms were constructed for each infant: five pre- and post-surfactant. If a plateau was present SIII was calculated by regression analysis. RESULTS Thirty-six infants were included, median gestational age of 28.7 weeks and birth weight of 1055 g. Average time between pre- and post-surfactant was 3.2 min. Three hundred and sixty capnograms (180 pre and post) were evaluated. There was adequate slope in 134 (74.4%) capnograms pre and in 100 (55.6%) capnograms post-surfactant (p = 0.004). Normalised for tidal volume SIII pre-surfactant was 18.89 mmHg and post-surfactant was 24.86 mmHg (p = 0.006). An increase in SIII produced an up-slanting appearance to the plateau indicating regional obstruction. CONCLUSION It was feasible to evaluate the alveolar plateau pre-surfactant in preterm infants. Ventilation inhomogeneity increased post-surfactant likely due to airway obstruction caused by liquid surfactant present in the airways. IMPACT Volumetric capnography can be used to assess homogeneity of ventilation by SIII analysis. Ventilation inhomogeneity increased immediately post-surfactant administration during the resuscitation of preterm infants, producing a characteristic up-slanting appearance to the alveolar plateau. The best determinant of alveolar plateau presence in preterm infants was the expired tidal volume.
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19
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Williams E, Dassios T, Dixon P, Greenough A. Physiological dead space and alveolar ventilation in ventilated infants. Pediatr Res 2022; 91:218-222. [PMID: 33603211 PMCID: PMC7891488 DOI: 10.1038/s41390-021-01388-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/18/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Dead space is the volume not taking part in gas exchange and, if increased, could affect alveolar ventilation if there is too low a delivered volume. We determined if there were differences in dead space and alveolar ventilation in ventilated infants with pulmonary disease or no respiratory morbidity. METHODS A prospective study of mechanically ventilated infants was undertaken. Expiratory tidal volume and carbon dioxide levels were measured. Volumetric capnograms were constructed to calculate the dead space using the modified Bohr-Enghoff equation. Alveolar ventilation (VA) was also calculated. RESULTS Eighty-one infants with a median (range) gestational age of 28.7 (22.4-41.9) weeks were recruited. The dead space [median (IQR)] was higher in 35 infants with respiratory distress syndrome (RDS) [5.7 (5.1-7.0) ml/kg] and in 26 infants with bronchopulmonary dysplasia (BPD) [6.4 (5.1-7.5) ml/kg] than in 20 term controls with no respiratory disease [3.5 (2.8-4.2) ml/kg, p < 0.001]. Minute ventilation was higher in both infants with RDS or BPD compared to the controls. VA in infants with RDS or BPD was similar to that of the controls [p = 0.54]. CONCLUSION Prematurely born infants with pulmonary disease have a higher dead space than term controls, which may influence the optimum level during volume-targeted ventilation. IMPACT Measurement of the dead space was feasible in ventilated newborn infants. The physiological dead space was a significant proportion of the delivered volume in ventilated infants. The dead space (per kilogram) was higher in ventilated infants with respiratory distress syndrome or evolving bronchopulmonary dysplasia compared to term controls without respiratory disease. The dead space volume should be considered when calculating the most appropriate volume during volume-targeted ventilation.
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Affiliation(s)
- Emma Williams
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Theodore Dassios
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, UK
| | | | - Anne Greenough
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
- Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.
- NIHR Biomedical Centre at Guy's and St Thomas NHS Foundation Trust, King's College London, London, UK.
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20
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Bennett K, Lewis K. Sedation and Anesthesia in Rodents. Vet Clin North Am Exot Anim Pract 2021; 25:211-255. [PMID: 34823692 DOI: 10.1016/j.cvex.2021.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Sedation and anesthesia in rodent species are complex due to their wide species variation, small size, and metabolism. This review article covers recent advances in sedation and anesthesia as well as an updated drug formulary for sedation protocols. Setup, equipment, monitoring, maintenance, and recovery are reviewed as well as species-specific anatomy.
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Affiliation(s)
- Katarina Bennett
- Avian & Exotics Service, Bluepearl Emergency and Specialty Hospital, 7414 S Tamiami Trl. Sarasota, FL 34231, USA.
| | - Kerrie Lewis
- Pebble Creek Animal Hospital, 19440 Bruce B Downs Boulevard, Tampa, FL 33647, USA
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21
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Williams E, Dassios T, Greenough A. Carbon dioxide monitoring in the newborn infant. Pediatr Pulmonol 2021; 56:3148-3156. [PMID: 34365738 DOI: 10.1002/ppul.25605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 11/06/2022]
Abstract
Carbon dioxide (CO2 ) monitoring is vital during mechanical ventilation of newborn infants, as morbidity increases when CO2 levels are inappropriate. Our aim was to review the uses and limitations of such noninvasive monitoring methods. Colorimetry is primarily utilized during resuscitation to determine whether successful intubation has occurred. False negative and positive results can however lead to delays in detecting tracheal versus esophageal intubation. Transcutaneous carbon dioxide sensors have limited use during resuscitation, but can be utilized to provide continuous trend data during on-going ventilation. End-tidal capnography can provide clinicians with quantitative end-tidal CO2 (EtCO2 ) values and a continuous real-time capnogram waveform trace. These devices are becoming more widely accepted for use in the neonatal population as the new devices are lightweight with minimal additional dead space. Nevertheless, they have been reported to have variable accuracy when compared to arterial CO2 measurements, however, divergence of results may be related to disease severity rather than technological limitations. During resuscitation EtCO2 can be detected by capnography more rapidly than by colorimetry. Furthermore, capnography can be currently utilized in neonatal research settings to determine the physiological dead space and ventilation inhomogeneity, and thus has potential to be beneficial to clinical care. In conclusion, novel modes of noninvasive carbon dioxide monitoring can be safely and reliably utilized in newborn infants during mechanical ventilation. Future randomized trials should aim to address which device provides the most optimal form of monitoring in different clinical contexts.
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Affiliation(s)
- Emma Williams
- Department of Woman and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Theodore Dassios
- Department of Woman and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Anne Greenough
- Department of Woman and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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22
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Zuiki M, Kume R, Matsuura A, Mitsuno K, Kitamura K, Kanayama T, Komatsu H. Large difference between Enghoff and Bohr dead space in ventilated infants with hypoxemic respiratory failure. Pediatr Pulmonol 2021; 56:2102-2107. [PMID: 33866691 DOI: 10.1002/ppul.25403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/16/2021] [Accepted: 03/26/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND Ventilated neonates with hypoxemic respiratory failure (HRF) may show a ventilation-perfusion (V/Q) mismatch. OBJECTIVE To evaluate the difference between the Bohr (Vd, Bohr ) and Enghoff (Vd, Enghoff ) dead spaces in infants by using volumetric capnography based on ventilator graphics and capnograms. METHODS This study enrolled 46 ventilated infants (mean birth weight, 2239 ± 640 g; mean gestational age, 35.5 ± 3.3 weeks). We performed volumetric capnography and calculated Vd, Bohr and Vd, Enghoff when arterial blood sampling was necessary for treatment. According to the oxygenation index (OI) based on the Montreux definition of neonatal acute respiratory distress syndrome, each measurement was classified into the HRF (OI ≥ 4) or control (OI < 4) group. Then, a regression analysis was performed to evaluate the correlation between the OI and the difference between Vd, Enghoff and Vd, Bohr . RESULTS The median Vd, Enghoff /tidal volume (VT ) was significantly higher in the HRF group (0.55 [interquartile range, 0.47-0.68]) than in the control group (0.46 [0.37-0.57]). The HRF group showed a larger difference between Vd, Enghoff /VT and Vd, Bohr /VT than the control group (median, 0.22 [0.15-0.29] vs. 0.10 [0.06-0.14], respectively). Moreover, the regression analysis of the relationship between OI and Vd, Enghoff /VT - Vd, Bohr /VT showed a positive correlation (r = .60, p < .001). CONCLUSION Ventilated neonates with hypoxemic respiratory failure showed a large difference between Vd, Enghoff and Vd, Bohr , possibly reflecting a low V/Q mismatch and right-to-left shunting.
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Affiliation(s)
- Masashi Zuiki
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan.,Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan
| | - Rika Kume
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan
| | - Amane Matsuura
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan
| | - Kohei Mitsuno
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan
| | - Kazumasa Kitamura
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan
| | - Takuyo Kanayama
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan
| | - Hiroshi Komatsu
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Maizuru, Kyoto, Japan
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23
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Williams E, Dassios T, O'Reilly N, Walsh A, Greenough A. End-tidal capnography monitoring in infants ventilated on the neonatal intensive care unit. J Perinatol 2021; 41:1718-1724. [PMID: 33649438 PMCID: PMC7917950 DOI: 10.1038/s41372-021-00978-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/22/2020] [Accepted: 01/28/2021] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To assess whether end-tidal capnography (EtCO2) monitoring reduced the magnitude of difference in carbon dioxide (CO2) levels and the number of blood gases in ventilated infants. STUDY DESIGN A case-control study of a prospective cohort (n = 36) with capnography monitoring and matched historical controls (n = 36). RESULT The infants had a median gestational age of 31.6 weeks. A reduction in the highest CO2 level on day 1 after birth was observed after the introduction of EtCO2 monitoring (p = 0.043). There was also a reduction in the magnitude of difference in CO2 levels on days 1 (p = 0.002) and 4 (p = 0.049) after birth. There was no significant difference in the number of blood gases. CONCLUSION Continuous end-tidal capnography monitoring in ventilated infants was associated with a reduction in the degree of the magnitude of difference in CO2 levels and highest level of CO2 on the first day after birth.
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Affiliation(s)
- Emma Williams
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Theodore Dassios
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, UK
| | - Niamh O'Reilly
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Alison Walsh
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Anne Greenough
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
- The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.
- NIHR Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK.
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Dassios T, Williams EE, Greenough A. Waveform capnography in neonatal intensive care: is it unreliable? Arch Dis Child Fetal Neonatal Ed 2021; 106:228. [PMID: 33203714 DOI: 10.1136/archdischild-2020-321007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/05/2020] [Indexed: 11/04/2022]
Affiliation(s)
- Theodore Dassios
- Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, London, UK
- Department of Women and Children's Health, School of Life Sciences, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Emma E Williams
- Department of Women and Children's Health, School of Life Sciences, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Anne Greenough
- Department of Women and Children's Health, School of Life Sciences, Faculty of Life Science and Medicine, King's College London, London, UK
- Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, London, UK
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Accuracy of a battery-powered portable capnometer in premature infants. J Clin Monit Comput 2021; 36:209-213. [PMID: 33385261 PMCID: PMC7775636 DOI: 10.1007/s10877-020-00638-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 12/17/2020] [Indexed: 11/25/2022]
Abstract
Carbon dioxide measurement is useful for confirmation of successful tracheal intubation and ensuring adequate ventilation. There are two types of CO2 detectors, i.e., single-use-only colorimetric devices and capnometers. Although portable capnometers are widely used for resuscitation, there have been no reports regarding their clinical utility in neonates. The correspondence between end-tidal CO2 (PetCO2) level determined using a battery-powered portable capnometer and arterial CO2 (PaCO2) was investigated using paired data obtained simultaneously from 26 neonates weighing 1262 ± 589 g at examination on mechanical ventilation. PetCO2 level and PaCO2 showed a strong correlation (r = 0.839, P < 0.001), and the correlation equation was: PetCO2 = 0.8 × PaCO2 + 1.1. Therefore, PetCO2 readings obtained with a battery-powered portable capnometer were likely to be underestimated. This became more pronounced with decreasing infant body weight at examination as the net difference in measurements of PaCO2 and PetCO2 was significantly positively correlated with infant body weight at examination (r = 0.451, P < 0.001). The observations presented here may be helpful in the use of battery-powered portable capnometers in neonates requiring controlled ventilation with tracheal intubation.
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Zuiki M, Naito Y, Kitamura K, Tsurukawa S, Matsumura U, Kanayama T, Komatsu H. Reduction in minute alveolar ventilation causes hypercapnia in ventilated neonates with respiratory distress. Eur J Pediatr 2021; 180:241-246. [PMID: 32748016 PMCID: PMC7397965 DOI: 10.1007/s00431-020-03761-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/19/2020] [Accepted: 07/28/2020] [Indexed: 11/28/2022]
Abstract
Hypercapnia occurs in ventilated infants even if tidal volume (VT) and minute ventilation (VE) are maintained. We hypothesised that increased physiological dead space (Vd,phys) caused decreased minute alveolar ventilation (VA; alveolar ventilation (VA) × respiratory rate) in well-ventilated infants with hypercapnia. We investigated the relationship between dead space and partial pressure of carbon dioxide (PaCO2) and assessed VA. Intubated infants (n = 33; mean birth weight, 2257 ± 641 g; mean gestational age, 35.0 ± 3.3 weeks) were enrolled. We performed volumetric capnography (Vcap), and calculated Vd,phys and VA when arterial blood sampling was necessary. PaCO2 was positively correlated with alveolar dead space (Vd,alv) (r = 0.54, p < 0.001) and Vd,phys (r = 0.48, p < 0.001), but not Fowler dead space (r = 0.14, p = 0.12). Normocapnia (82 measurements; 35 mmHg ≤ PaCO2 < 45 mmHg) and hypercapnia groups (57 measurements; 45 mmHg ≤ PaCO2) were classified. The hypercapnia group had higher Vd,phys (median 0.57 (IQR, 0.44-0.67)) than the normocapnia group (median Vd,phys/VT = 0.46 (IQR, 0.37-0.58)], with no difference in VT. The hypercapnia group had lower VA (123 (IQR, 87-166) ml/kg/min) than the normocapnia group (151 (IQR, 115-180) ml/kg/min), with no difference in VE.Conclusion: Reduction of VA in well-ventilated neonates induces hypercapnia, caused by an increase in Vd,phys. What is Known: • Volumetric capnography based on ventilator graphics and capnograms is a useful tool in determining physiological dead space of ventilated infants and investigating the cause of hypercapnia. What is New: • This study adds evidence that reduction in minute alveolar ventilation causes hypercapnia in ventilated neonates.
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Affiliation(s)
- Masashi Zuiki
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502, Japan.
| | - Yuki Naito
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502 Japan
| | - Kazumasa Kitamura
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502 Japan
| | - Shinichiro Tsurukawa
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502 Japan
| | - Utsuki Matsumura
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502 Japan
| | - Takuyo Kanayama
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502 Japan
| | - Hiroshi Komatsu
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, 2410 Yukinaga, Maizuru, Kyoto, 625-8502 Japan
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Williams EE, Dassios T, Murthy V, Greenough A. Anatomical deadspace during resuscitation of infants with congenital diaphragmatic hernia. Early Hum Dev 2020; 149:105150. [PMID: 32777695 DOI: 10.1016/j.earlhumdev.2020.105150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Congenital diaphragmatic hernia (CDH) has a high mortality and morbidity related to pulmonary hypoplasia. AIMS To test the hypothesis that CDH infants who survived would have a greater anatomical deadspace reflecting less severe pulmonary hypoplasia. Furthermore, infants with CDH who had undergone feto-tracheal occlusion (FETO) would have a greater anatomical deadspace. STUDY DESIGN Infants were studied during resuscitation in the delivery suite. They were all intubated immediately at delivery, given a neuromuscular blocking agent and underwent respiratory monitoring. The anatomical deadspace was calculated from volumetric capnography measurements. SUBJECTS Thirty infants born at 32 weeks of gestation or greater and diagnosed antenatally with a CDH were studied. Eleven had undergone FETO and overall five died. OUTCOME MEASURES Anatomical deadspace (VdANA) and survival to discharge. RESULTS The median (IQR) gestational age of the infants was 38.1 (35.2-39.3) weeks and birthweight 2.8 (2.3-3.3) kg. The anatomical deadspace was higher in those infants who survived (2.9 (2.8-3.3) mls/kg) compared to those who died (2.2 (2.1-2.7) mls/kg; p = 0.003) and was higher in those who had undergone FETO (3.0 (2.8-3.8) mls/kg) compared to those who had not (2.8 (2.4-3.0) mls/kg; p = 0.032). In predicting survival to discharge, the anatomical deadspace had an AUC of 0.90 (p = 0.006). CONCLUSIONS CDH infants who survived had a larger anatomical deadspace than those who died suggesting they had less lung hypoplasia. In addition, infants who had undergone FETO had greater anatomical deadspace possibly reflecting distension of the conducting airways.
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Affiliation(s)
- Emma E Williams
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Science and Medicine, King's College London, SE5 9RS, United Kingdom
| | - Theodore Dassios
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Science and Medicine, King's College London, SE5 9RS, United Kingdom; Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London SE5 9RS, United Kingdom.
| | - Vadivelam Murthy
- Neonatal Intensive Care Centre, The Royal London Hospital-Barts Health NHS Foundation Trust, London E1 11B, United Kingdom
| | - Anne Greenough
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Science and Medicine, King's College London, SE5 9RS, United Kingdom; Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, SE1 9RT, United Kingdom; NIHR Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust, King's College London, SE1 9RT, United Kingdom
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Dassios T, Dixon P, Williams E, Greenough A. Volumetric capnography slopes in ventilated term and preterm infants. Physiol Meas 2020; 41:055001. [DOI: 10.1088/1361-6579/ab89c7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Williams E, Dassios T, Greenough A. Assessment of sidestream end-tidal capnography in ventilated infants on the neonatal unit. Pediatr Pulmonol 2020; 55:1468-1473. [PMID: 32187888 DOI: 10.1002/ppul.24738] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/11/2020] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Continuous monitoring of carbon dioxide (CO2 ) levels can be achieved by capnography. Our aims were to compare the performance of a sidestream capnograph with a low dead space and sampling rate to a mainstream device and evaluate whether its results correlated with arterial/capillary CO2 levels in infants with different respiratory disease severities. WORKING HYPOTHESES End-tidal carbon dioxide (EtCO2 ) results by sidestream and mainstream capnography would correlate, but the divergence of EtCO2 and CO2 results would occur in more severe lung disease. STUDY DESIGN Prospective cohort study. PATIENT-SUBJECT SELECTION Fifty infants with a median (interquartile range) gestational age of 31.1 (27.1-37.4) weeks and birth weight of 1.37 (0.76-2.95) kg. METHODOLOGY Concurrent measurements of EtCO2 in ventilated infants were made using a new Microstream sidestream device and a mainstream capnograph (gold standard). Results from both devices were compared with arterial or capillary CO2 levels. The ratio of dead space to tidal volume (Vd/Vt) was calculated to assess respiratory disease severity. RESULTS The mean difference between the concurrent measurements of EtCO2 was -0.54 ± 0.67 kPa (95% agreement levels - 1.86 to 0.77 kPa), the correlation between the two was r = .85 (P < .001). Sidestream capnography results correlated better with partial pressure of CO2 (PCO2 ) levels in infants with less (Vd/Vt < 0.35; r2 = .66, P < .001) rather than more severe (Vd/Vt > 0.35; r2 = .33, P = .01) lung disease. CONCLUSIONS The sidestream capnography performed similarly to the mainstream capnography. The poorer correlation of EtCO2 to PCO2 levels in infants with severe respiratory disease should highlight to clinicians increased ventilation-perfusion mismatch.
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Affiliation(s)
- Emma Williams
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Theodore Dassios
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, UK
| | - Anne Greenough
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.,NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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30
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Zuiki M, Yamano A, Kitamura K, Goda T, Oya S, Komatsu H. Ventilated Infants Have Increased Dead Space and Lower Alveolar Tidal Volumes during the Early versus Recovery Phase of Respiratory Distress. Neonatology 2020; 117:189-192. [PMID: 31825947 DOI: 10.1159/000504710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 11/12/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Few studies have reported the measurement of anatomical dead space (Vd,an) and alveolar tidal volume (VA) in ventilated neonates with respiratory distress. OBJECTIVE The aim of this study was to determine the differences in Vd,an and VA in ventilated infants between the early and recovery phases of respiratory distress using volumetric -capnography (Vcap) based on ventilator graphics and capnograms. METHODS This study enrolled twenty-five ventilated infants (mean birth weight, 2,220 ± 635 g; mean gestational age, 34.7 ± 3.3 weeks). We adjusted respiratory settings to maintain appropriate oxygenation and tidal volume (VT), and performed Vcap based on waveforms of ventilator graphics and capnograms. Vd,an and VAwere measured in infants with respiratory disorders, immediately after intubation (early phase) and subsequently when they were clinically stable (recovery phase). RESULTS The early phase, with lower dynamic lung compliance, required a higher level of ventilator support, not positive end-expiratory pressure, than the recovery phase. There were significant differences between the early and recovery phases for Vd,an (mean difference in Vd,an/kg = 0.57 mL/kg; 95% confidence interval [CI], 0.38-0.77; mean difference in Vd,an/VT = 0.10; 95% CI, 0.07-0.14) and VA (mean difference in VA/kg = -0.60 mL/kg; 95% CI, -0.94 to -0.27; mean difference in VA/VT = -0.12; 95% CI, -0.15 to -0.09), despite no difference in VT. CONCLUSIONS We evaluated changes in Vd,an and VA during mechanical ventilation using Vcap based on waveforms. The increase in Vd,an and decrease in VA suggested dilation of the airways and collapse of the alveoli in ventilated infants with low lung compliance.
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Affiliation(s)
- Masashi Zuiki
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Kyoto, Japan,
| | - Akio Yamano
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Kyoto, Japan
| | - Kazumasa Kitamura
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Kyoto, Japan
| | - Takeshi Goda
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Kyoto, Japan
| | - Satoshi Oya
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Kyoto, Japan
| | - Hiroshi Komatsu
- Department of Pediatrics, National Hospital Organization Maizuru Medical Center, Kyoto, Japan
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Hochwald O, Borenstein-Levin L, Dinur G, Jubran H, Ben-David S, Kugelman A. Continuous Noninvasive Carbon Dioxide Monitoring in Neonates: From Theory to Standard of Care. Pediatrics 2019; 144:peds.2018-3640. [PMID: 31248940 DOI: 10.1542/peds.2018-3640] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/25/2019] [Indexed: 11/24/2022] Open
Abstract
Ventilatory support may affect the short- and long-term neurologic and respiratory morbidities of preterm infants. Ongoing monitoring of oxygenation and ventilation and control of adequate levels of oxygen, pressures, and volumes can decrease the incidence of such adverse outcomes. Use of pulse oximetry became a standard of care for titrating oxygen delivery, but continuous noninvasive monitoring of carbon dioxide (CO2) is not routinely used in NICUs. Continuous monitoring of CO2 level may be crucial because hypocarbia and hypercarbia in extremely preterm infants are associated with lung and brain morbidities, specifically bronchopulmonary dysplasia, intraventricular hemorrhage, and cystic periventricular leukomalacia. It is shown that continuous monitoring of CO2 levels helps in maintaining stable CO2 values within an accepted target range. Continuous monitoring of CO2 levels can be used in the delivery room, during transport, and in infants receiving invasive or noninvasive respiratory support in the NICU. It is logical to hypothesize that this will result in better outcome for extremely preterm infants. In this article, we review the different noninvasive CO2 monitoring alternatives and devices, their advantages and disadvantages, and the available clinical data supporting or negating their use as a standard of care in NICUs.
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Affiliation(s)
- Ori Hochwald
- Department of Neonatology, Rambam Health Care Campus, Haifa, Israel; and .,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Liron Borenstein-Levin
- Department of Neonatology, Rambam Health Care Campus, Haifa, Israel; and.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Gil Dinur
- Department of Neonatology, Rambam Health Care Campus, Haifa, Israel; and.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Huda Jubran
- Department of Neonatology, Rambam Health Care Campus, Haifa, Israel; and.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shlomit Ben-David
- Department of Neonatology, Rambam Health Care Campus, Haifa, Israel; and.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Amir Kugelman
- Department of Neonatology, Rambam Health Care Campus, Haifa, Israel; and.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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Rocha G, Soares P, Gonçalves A, Silva AI, Almeida D, Figueiredo S, Pissarra S, Costa S, Soares H, Flôr-de-Lima F, Guimarães H. Respiratory Care for the Ventilated Neonate. Can Respir J 2018; 2018:7472964. [PMID: 30186538 PMCID: PMC6110042 DOI: 10.1155/2018/7472964] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/12/2018] [Indexed: 11/19/2022] Open
Abstract
Invasive ventilation is often necessary for the treatment of newborn infants with respiratory insufficiency. The neonatal patient has unique physiological characteristics such as small airway caliber, few collateral airways, compliant chest wall, poor airway stability, and low functional residual capacity. Pathologies affecting the newborn's lung are also different from many others observed later in life. Several different ventilation modes and strategies are available to optimize mechanical ventilation and to prevent ventilator-induced lung injury. Important aspects to be considered in ventilating neonates include the use of correct sized endotracheal tube to minimize airway resistance and work of breathing, positioning of the patient, the nursing care, respiratory kinesiotherapy, sedation and analgesia, and infection prevention, namely, the ventilator-associated pneumonia and nosocomial infection, as well as prevention and treatment of complications such as air leaks and pulmonary hemorrhage. Aspects of ventilation in patients under ECMO (extracorporeal membrane oxygenation) and in palliative care are of increasing interest nowadays. Online pulmonary mechanics and function testing as well as capnography are becoming more commonly used. Echocardiography is now a routine in most neonatal units. Near infrared spectroscopy (NIRS) is an attractive tool potentially helping in preventing intraventricular hemorrhage and periventricular leukomalacia. Lung ultrasound is an emerging tool of diagnosis and can be of added value in helping monitoring the ventilated neonate. The aim of this scientific literature review is to address relevant aspects concerning the respiratory care and monitoring of the invasively ventilated newborn in order to help physicians to optimize the efficacy of care.
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Affiliation(s)
- Gustavo Rocha
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
| | - Paulo Soares
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - Américo Gonçalves
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
| | - Ana Isabel Silva
- Department of Physical and Rehabilitation Medicine, Centro Hospitalar São João, Porto, Portugal
| | - Diana Almeida
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
| | - Sara Figueiredo
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
| | - Susana Pissarra
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - Sandra Costa
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - Henrique Soares
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - Filipa Flôr-de-Lima
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - Hercília Guimarães
- Department of Neonatology, Centro Hospitalar São João, Porto, Portugal
- Faculty of Medicine, University of Porto, Porto, Portugal
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Dassios T, Dixon P, Hickey A, Fouzas S, Greenough A. Physiological and anatomical dead space in mechanically ventilated newborn infants. Pediatr Pulmonol 2018; 53:57-63. [PMID: 29152912 DOI: 10.1002/ppul.23918] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/01/2017] [Indexed: 11/08/2022]
Abstract
OBJECTIVES To compare the anatomical (VD-Ana ) and alveolar dead space (VD-Alv ) in term and prematurely born infants and identify the clinical determinants of those indices. WORKING HYPOTHESIS VD-Ana and VD-Alv will be higher in prematurely born compared to term born infants. STUDY DESIGN Retrospective analysis of data collected at King's College Hospital NHS Foundation Trust, London, UK. PATIENT SELECTION Fifty-six infants (11 term, 45 preterm) were studied at a median age of 8 (IQR 2-33) days. METHODOLOGY VD-Ana was determined using Fowler's method of volumetric capnography. VD-Alv was determined by subtracting VD-Ana from the physiological dead space which was determined by the Bohr-Enghoff equation. VD-Ana and VD-Alv were related to body weight at the time of study. RESULTS The median VD-Ana /kg was higher in prematurely born infants [3.7 (IQR: 3.0-4.5) mL/kg] compared to term infants [2.4 (IQR: 1.9-2.9) mL/kg, adjusted P = 0.001]. The median VD-Alv /kg was not higher in prematurely born infants [0.3 (IQR: 0.1-0.5)] compared to term infants [0.1 (IQR: 0.0-0.2) mL/kg] after adjusting for differences in respiratory rate and days of ventilation (P = 0.482). VD-Ana /kg was related to postmenstrual age (r = -0.388, P < 0.001), birth weight (r = -0.397, P < 0.001), and weight at measurement (r = -0.476, P < 0.001). VD-Alv /kg was related to postmenstrual age (r = -0.254, P < 0.001), birth weight (r = -0.291, P = 0.002), and weight at measurement (r = -0.281, P = 0.003) and related to days of ventilation (r = 0.194, P = 0.044). CONCLUSIONS VD-Ana /kg and VD-Alv /kg increased with decreasing weight and gestation. VD-Alv was higher in infants that have undergone prolonged mechanical ventilation.
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Affiliation(s)
- Theodore Dassios
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Paul Dixon
- Individual Consultant, London, United Kingdom
| | - Ann Hickey
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Sotirios Fouzas
- Paediatric Respiratory Unit, University Hospital of Patras, Patras, Greece
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom.,NIHR Biomedical Centre at Guy's and St Thomas NHS Foundation Trust and King's College London, United Kingdom
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Lin HJ, Huang CT, Hsiao HF, Chiang MC, Jeng MJ. End-tidal carbon dioxide measurement in preterm infants with low birth weight. PLoS One 2017; 12:e0186408. [PMID: 29040312 PMCID: PMC5645127 DOI: 10.1371/journal.pone.0186408] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 09/29/2017] [Indexed: 02/06/2023] Open
Abstract
Objective There are conflicting data regarding the use of end-tidal carbon dioxide (PetCO2) measurement in preterm infants. The aim of this study was to evaluate the effects of different dead space to tidal volume ratios (VD/VT) on the correlation between PetCO2 and arterial carbon dioxide pressure (PaCO2) in ventilated preterm infants with respiratory distress syndrome (RDS). Methods We enrolled ventilated preterm infants (with assist control mode or synchronous intermittent mandatory mode) with RDS who were treated with surfactant in this prospective study. Simultaneous PetCO2 and PaCO2 data pairs were obtained from ventilated neonates monitored using mainstream capnography. Data obtained before and after surfactant treatment were also analyzed. Results One-hundred and one PetCO2 and PaCO2 pairs from 34 neonates were analyzed. There was a moderate correlation between PetCO2 and PaCO2 values (r = 0.603, P < 0.01). The correlation was higher in the post-surfactant treatment group (r = 0.786, P < 0.01) than the pre-surfactant treatment group (r = 0.235). The values of PaCO2 and PetCO2 obtained based on the treatment stage of surfactant therapy were 42.4 ± 8.6 mmHg and 32.6 ± 7.2 mmHg, respectively, in pre-surfactant treatment group, and 37.8 ± 10.3 mmHg and 33.7 ± 9.3 mmHg, respectively, in the post-surfactant treatment group. Furthermore, we found a significant decrease in VD/VT in the post-surfactant treatment group when compared to the pre-surfactant treatment group (P = 0.003). Conclusions VD/VT decreased significantly after surfactant therapy and the correlation between PetCO2 and PaCO2 was higher after surfactant therapy in preterm infants with RDS.
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Affiliation(s)
- Hsin-Ju Lin
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ching-Tzu Huang
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei, Taiwan
- Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Hsiu-Feng Hsiao
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Ming-Chou Chiang
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Chang Gung University College of Medicine, Taoyuan, Taiwan
- Division of Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- * E-mail: (MCC); (MJJ)
| | - Mei-Jy Jeng
- Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Pediatrics, Children’s Medical Center, Taipei Veterans General Hospital, Taipei, Taiwan
- * E-mail: (MCC); (MJJ)
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Dassios T, Kaltsogianni O, Greenough A. Determinants of pulmonary dead space in ventilated newborn infants. Early Hum Dev 2017; 108:29-32. [PMID: 28371672 DOI: 10.1016/j.earlhumdev.2017.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Pulmonary dead space (VD) is an index of ventilation inhomogeneity and one of the determinants of the magnitude of tidal volume to maintain optimal blood gases. AIMS To identify the determinants of VD in ventilated newborns and to investigate differences in VD between prematurely born and term infants and those prematurely born infants who did or did not develop bronchopulmonary dysplasia (BPD). METHODS Sixty-one mechanically ventilated infants (15 term, 46 preterm) were studied at a median age of 8 (IQR 2-31) days; 32 of the preterm infants developed BPD. VD was determined from the difference between arterial and end tidal carbon dioxide (CO2) using a low dead space CO2 detector using the Bohr/Enghoff equation and was related to body weight (VD/kg) at the time of study. The time to peak tidal expiratory flow/expiratory time (TPTEF/TE) was measured during spontaneous breathing using a fixed orifice pneumotachograph. RESULTS VD/kg was related to gestational age (r=-0.285, p=0.001), birth weight (r=-0.356, p<0.001), weight (r=-0.316, p<0.001) and postmenstrual age (r=-0.205, p=0.020) at measurement, days of ventilation (r=0.322, p<0.001) and TPTEF/TE (r=-0.397, p=0.003). The median VD/kg was higher in prematurely born infants [2.3 (IQR: 1.7-3.0) ml/kg] compared to term infants [1.5 (1.3-2.1) ml/kg, (p=0.003)] and in premature infants that developed BPD [2.6 (IQR 1.8-3.4) ml/kg] compared to those who did not [1.7 (IQR 1.1-1.9) ml/kg], (p<0.001). CONCLUSIONS Numerous factors influence pulmonary dead space and thus an optimum tidal volume will differ according to the underlying demographics and respiratory status.
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Affiliation(s)
- Theodore Dassios
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK.
| | - Ourania Kaltsogianni
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, UK; National Institute for Health Research (NIHR), Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, UK
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Medical Devices for Pediatric Apnea Monitoring and Therapy: Past and New Trends. IEEE Rev Biomed Eng 2017; 10:199-212. [DOI: 10.1109/rbme.2017.2757899] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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