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Bachmann KF, Moller PW, Hunziker L, Maggiorini M, Berger D. Mechanisms maintaining right ventricular contractility-to-pulmonary arterial elastance ratio in VA ECMO: a retrospective animal data analysis of RV-PA coupling. J Intensive Care 2024; 12:19. [PMID: 38734616 PMCID: PMC11088130 DOI: 10.1186/s40560-024-00730-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/14/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND To optimize right ventricular-pulmonary coupling during veno-arterial (VA) ECMO weaning, inotropes, vasopressors and/or vasodilators are used to change right ventricular (RV) function (contractility) and pulmonary artery (PA) elastance (afterload). RV-PA coupling is the ratio between right ventricular contractility and pulmonary vascular elastance and as such, is a measure of optimized crosstalk between ventricle and vasculature. Little is known about the physiology of RV-PA coupling during VA ECMO. This study describes adaptive mechanisms for maintaining RV-PA coupling resulting from changing pre- and afterload conditions in VA ECMO. METHODS In 13 pigs, extracorporeal flow was reduced from 4 to 1 L/min at baseline and increased afterload (pulmonary embolism and hypoxic vasoconstriction). Pressure and flow signals estimated right ventricular end-systolic elastance and pulmonary arterial elastance. Linear mixed-effect models estimated the association between conditions and elastance. RESULTS At no extracorporeal flow, end-systolic elastance increased from 0.83 [0.66 to 1.00] mmHg/mL at baseline by 0.44 [0.29 to 0.59] mmHg/mL with pulmonary embolism and by 1.36 [1.21 to 1.51] mmHg/mL with hypoxic pulmonary vasoconstriction (p < 0.001). Pulmonary arterial elastance increased from 0.39 [0.30 to 0.49] mmHg/mL at baseline by 0.36 [0.27 to 0.44] mmHg/mL with pulmonary embolism and by 0.75 [0.67 to 0.84] mmHg/mL with hypoxic pulmonary vasoconstriction (p < 0.001). Coupling remained unchanged (2.1 [1.8 to 2.3] mmHg/mL at baseline; - 0.1 [- 0.3 to 0.1] mmHg/mL increase with pulmonary embolism; - 0.2 [- 0.4 to 0.0] mmHg/mL with hypoxic pulmonary vasoconstriction, p > 0.05). Extracorporeal flow did not change coupling (0.0 [- 0.0 to 0.1] per change of 1 L/min, p > 0.05). End-diastolic volume increased with decreasing extracorporeal flow (7.2 [6.6 to 7.8] ml change per 1 L/min, p < 0.001). CONCLUSIONS The right ventricle dilates with increased preload and increases its contractility in response to afterload changes to maintain ventricular-arterial coupling during VA extracorporeal membrane oxygenation.
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Affiliation(s)
- Kaspar F Bachmann
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
| | - Per Werner Moller
- Department of Anesthesia, SV Hospital Group, Institute of Clinical Sciences at the Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lukas Hunziker
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marco Maggiorini
- Medical Intensive Care Unit, University Hospital Zürich, University of Zürich, Zurich, Switzerland
| | - David Berger
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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Berger D, Werner Moller P, Bachmann KF. Cardiopulmonary interactions-which monitoring tools to use? Front Physiol 2023; 14:1234915. [PMID: 37621761 PMCID: PMC10445648 DOI: 10.3389/fphys.2023.1234915] [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] [Received: 06/05/2023] [Accepted: 07/18/2023] [Indexed: 08/26/2023] Open
Abstract
Heart-lung interactions occur due to the mechanical influence of intrathoracic pressure and lung volume changes on cardiac and circulatory function. These interactions manifest as respiratory fluctuations in venous, pulmonary, and arterial pressures, potentially affecting stroke volume. In the context of functional hemodynamic monitoring, pulse or stroke volume variation (pulse pressure variation or stroke volume variability) are commonly employed to assess volume or preload responsiveness. However, correct interpretation of these parameters requires a comprehensive understanding of the physiological factors that determine pulse pressure and stroke volume. These factors include pleural pressure, venous return, pulmonary vessel function, lung mechanics, gas exchange, and specific cardiac factors. A comprehensive knowledge of heart-lung physiology is vital to avoid clinical misjudgments, particularly in cases of right ventricular (RV) failure or diastolic dysfunction. Therefore, when selecting monitoring devices or technologies, these factors must be considered. Invasive arterial pressure measurements of variations in breath-to-breath pressure swings are commonly used to monitor heart-lung interactions. Echocardiography or pulmonary artery catheters are valuable tools for differentiating preload responsiveness from right ventricular failure, while changes in diastolic function should be assessed alongside alterations in airway or pleural pressure, which can be approximated by esophageal pressure. In complex clinical scenarios like ARDS, combined forms of shock or right heart failure, additional information on gas exchange and pulmonary mechanics aids in the interpretation of heart-lung interactions. This review aims to describe monitoring techniques that provide clinicians with an integrative understanding of a patient's condition, enabling accurate assessment and patient care.
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Affiliation(s)
- David Berger
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Per Werner Moller
- Department of Anaesthesia, SV Hospital Group, Institute of Clinical Sciences at the Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kaspar F. Bachmann
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of Anaesthesiology and Intensive Care, University of Tartu, Tartu, Estonia
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de Carvalho EB, Battaglini D, Robba C, Malbrain MLNG, Pelosi P, Rocco PRM, Silva PL. Fluid management strategies and their interaction with mechanical ventilation: from experimental studies to clinical practice. Intensive Care Med Exp 2023; 11:44. [PMID: 37474816 PMCID: PMC10359242 DOI: 10.1186/s40635-023-00526-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/31/2023] [Indexed: 07/22/2023] Open
Abstract
Patients on mechanical ventilation may receive intravenous fluids via restrictive or liberal fluid management. A clear and objective differentiation between restrictive and liberal fluid management strategies is lacking in the literature. The liberal approach has been described as involving fluid rates ranging from 1.2 to 12 times higher than the restrictive approach. A restrictive fluid management may lead to hypoperfusion and distal organ damage, and a liberal fluid strategy may result in endothelial shear stress and glycocalyx damage, cardiovascular complications, lung edema, and distal organ dysfunction. The association between fluid and mechanical ventilation strategies and how they interact toward ventilator-induced lung injury (VILI) could potentiate the damage. For instance, the combination of a liberal fluids and pressure-support ventilation, but not pressure control ventilation, may lead to further lung damage in experimental models of acute lung injury. Moreover, under liberal fluid management, the application of high positive end-expiratory pressure (PEEP) or an abrupt decrease in PEEP yielded higher endothelial cell damage in the lungs. Nevertheless, the translational aspects of these findings are scarce. The aim of this narrative review is to provide better understanding of the interaction between different fluid and ventilation strategies and how these interactions may affect lung and distal organs. The weaning phase of mechanical ventilation and the deresuscitation phase are not explored in this review.
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Affiliation(s)
- Eduardo Butturini de Carvalho
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- University of Vassouras, Rio de Janeiro, Brazil
| | | | - Chiara Robba
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
| | - Manu L. N. G. Malbrain
- First Department of Anesthesiology and Intensive Therapy, Medical University of Lublin, Lublin, Poland
- International Fluid Academy, Lovenjoel, Belgium
| | - Paolo Pelosi
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
| | - Patricia Rieken Macedo Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Gong X, Zhu L, Zhang M, Liu Y, Li C, Xu Z, Zheng J. Utilizing Spontaneous Ventilation Modes in Patients Underwent Corrective Surgery for Right Ventricular Outflow Tract Obstructive Congenital Heart Disease: A Crossover Study. Rev Cardiovasc Med 2023; 24:143. [PMID: 39076742 PMCID: PMC11273051 DOI: 10.31083/j.rcm2405143] [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] [Received: 11/22/2022] [Revised: 01/02/2023] [Accepted: 01/10/2023] [Indexed: 07/31/2024] Open
Abstract
Background This study aimed to determine whether the hemodynamics of patients with right ventricle outflow tract obstructive congenital heart disease (RVOTO-CHD) improve after corrective surgery by changing the ventilation mode. Methods Patients with RVOTO-CHD who underwent corrective surgery were enrolled in this study. Echocardiography and advanced hemodynamic monitoring were performed using the pulse indicator continuous cardiac output (PiCCO) technology in the pressure-regulated volume control (PRVC) mode, followed with switching to the pressure support ventilation (PSV) mode and neurally adjusted ventilatory assist (NAVA) mode in random order. Results Overall, 31 patients were enrolled in this study from April 2021 to October 2021. Notably, changing the ventilation mode from PRVC to a spontaneous mode (PSV or NAVA) led to better cardiac function outcomes, including right ventricular cardiac index (PRVC: 3.19 ± 1.07 L/min/ m 2 vs. PSV: 3.45 ± 1.32 L/min/ m 2 vs. NAVA: 3.82 ± 1.03 L/min/ m 2 , p < 0.05) and right ventricle contractility (tricuspid annular peak systolic velocity) (PRVC: 6.58 ± 1.40 cm/s vs. PSV: 7.03 ± 1.33 cm/s vs. NAVA: 7.94 ± 1.50 cm/s, p < 0.05), as detected via echocardiography. Moreover, in the NAVA mode, PiCCO-derived cardiac index (PRVC: 2.92 ± 0.54 L/min/ m 2 vs. PSV: 3.04 ± 0.56 L/min/ m 2 vs. NAVA: 3.20 ± 0.62 L/min/ m 2 , p < 0.05), stroke volume index (PRVC: 20.38 ± 3.97 mL/ m 2 vs. PSV: 21.23 ± 4.33 mL/ m 2 vs. NAVA: 22.00 ± 4.33 mL/ m 2 , p < 0.05), and global end diastolic index (PRVC: 295.74 ± 78.39 mL/ m 2 vs. PSV: 307.26 ± 91.18 mL/ m 2 vs. NAVA: 323.74 ± 102.87 mL/ m 2 , p < 0.05) improved, whereas extravascular lung water index significantly reduced (PRVC: 16.42 ± 7.90 mL/kg vs. PSV: 15.42 ± 5.50 mL/kg vs. NAVA: 14.4 ± 4.19 mL/kg, p < 0.05). Furthermore, peak inspiratory pressure, mean airway pressure, driving pressure, and compliance of the respiratory system improved in the NAVA mode. No deaths were reported in this study. Conclusions We found that utilizing spontaneous ventilator modes, especially the NAVA mode, after corrective surgery in patients with RVOTO-CHD may improve their right heart hemodynamics and respiratory mechanics. However, further randomized controlled trials are required to verify the advantages of spontaneous ventilation modes in such patients. Clinical Trial Registration NCT04825054.
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Affiliation(s)
- Xiaolei Gong
- Cardiac Intensive Care Unit, Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
| | - Limin Zhu
- Cardiac Intensive Care Unit, Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
| | - Mingjie Zhang
- Cardiac Intensive Care Unit, Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
| | - Yujie Liu
- Cardiac Intensive Care Unit, Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
| | - Chunxiang Li
- Cardiac Intensive Care Unit, Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
| | - Zhuoming Xu
- Cardiac Intensive Care Unit, Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
| | - Jinghao Zheng
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, 200127 Shanghai, China
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Berger D, Wigger O, de Marchi S, Grübler MR, Bloch A, Kurmann R, Stalder O, Bachmann KF, Bloechlinger S. The effects of positive end-expiratory pressure on cardiac function: a comparative echocardiography-conductance catheter study. Clin Res Cardiol 2022; 111:705-719. [PMID: 35381904 PMCID: PMC9151717 DOI: 10.1007/s00392-022-02014-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/21/2022] [Indexed: 01/09/2023]
Abstract
Background Echocardiographic parameters of diastolic function depend on cardiac loading conditions, which are altered by positive pressure ventilation. The direct effects of positive end-expiratory pressure (PEEP) on cardiac diastolic function are unknown. Methods Twenty-five patients without apparent diastolic dysfunction undergoing coronary angiography were ventilated noninvasively at PEEPs of 0, 5, and 10 cmH2O (in randomized order). Echocardiographic diastolic assessment and pressure–volume-loop analysis from conductance catheters were compared. The time constant for pressure decay (τ) was modeled with exponential decay. End-diastolic and end-systolic pressure volume relationships (EDPVRs and ESPVRs, respectively) from temporary caval occlusion were analyzed with generalized linear mixed-effects and linear mixed models. Transmural pressures were calculated using esophageal balloons. Results τ values for intracavitary cardiac pressure increased with the PEEP (n = 25; no PEEP, 44 ± 5 ms; 5 cmH2O PEEP, 46 ± 6 ms; 10 cmH2O PEEP, 45 ± 6 ms; p < 0.001). This increase disappeared when corrected for transmural pressure and diastole length. The transmural EDPVR was unaffected by PEEP. The ESPVR increased slightly with PEEP. Echocardiographic mitral inflow parameters and tissue Doppler values decreased with PEEP [peak E wave (n = 25): no PEEP, 0.76 ± 0.13 m/s; 5 cmH2O PEEP, 0.74 ± 0.14 m/s; 10 cmH2O PEEP, 0.68 ± 0.13 m/s; p = 0.016; peak A wave (n = 24): no PEEP, 0.74 ± 0.12 m/s; 5 cmH2O PEEP, 0.7 ± 0.11 m/s; 10 cmH2O PEEP, 0.67 ± 0.15 m/s; p = 0.014; E’ septal (n = 24): no PEEP, 0.085 ± 0.016 m/s; 5 cmH2O PEEP, 0.08 ± 0.013 m/s; 10 cmH2O PEEP, 0.075 ± 0.012 m/s; p = 0.002]. Conclusions PEEP does not affect active diastolic relaxation or passive ventricular filling properties. Dynamic echocardiographic filling parameters may reflect changing loading conditions rather than intrinsic diastolic function. PEEP may have slight positive inotropic effects. Clinical trial registration https://clinicaltrials.gov/ct2/show/NCT02267291, registered 17. October 2014. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1007/s00392-022-02014-1.
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Affiliation(s)
- David Berger
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, 3010, Bern, Switzerland.
| | - Olivier Wigger
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Klinik Für Kardiologie, Kantonsspital Winterthur, Winterthur, Switzerland
| | - Stefano de Marchi
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Martin R Grübler
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Andreas Bloch
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, 3010, Bern, Switzerland
- Zentrum Für Intensivmedizin, Kantonsspital Luzern, Luzern, Switzerland
| | - Reto Kurmann
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Klinik Für Kardiologie, Kantonsspital Luzern, Luzern, Switzerland
| | | | - Kaspar Felix Bachmann
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, 3010, Bern, Switzerland
- Zentrum Für Intensivmedizin, Kantonsspital Luzern, Luzern, Switzerland
- Department of Anesthesiology and Pain Medicine, Inselspital, Bern University Hospital,, University of Bern, Bern, Switzerland
| | - Stefan Bloechlinger
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, 3010, Bern, Switzerland
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Klinik Für Kardiologie, Kantonsspital Winterthur, Winterthur, Switzerland
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Valenti E, Moller PW, Takala J, Berger D. Collapsibility of caval vessels and right ventricular afterload: decoupling of stroke volume variation from preload during mechanical ventilation. J Appl Physiol (1985) 2021; 130:1562-1572. [PMID: 33734829 DOI: 10.1152/japplphysiol.01039.2020] [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: 11/22/2022] Open
Abstract
Collapsibility of caval vessels and stroke volume and pulse pressure variations (SVV, PPV) are used as indicators of volume responsiveness. Their behavior under increasing airway pressures and changing right ventricular afterload is incompletely understood. If the phenomena of SVV and PPV augmentation are manifestations of decreasing preload, they should be accompanied by decreasing transmural right atrial pressures. Eight healthy pigs equipped with ultrasonic flow probes on the pulmonary artery were exposed to positive end-expiratory pressure of 5 and 10 cmH2O and three volume states (Euvolemia, defined as SVV < 10%, Bleeding, and Retransfusion). SVV and PPV were calculated for the right and PPV for the left side of the circulation at increasing inspiratory airway pressures (15, 20, and 25 cmH2O). Right ventricular afterload was assessed by surrogate flow profile parameters. Transmural pressures in the right atrium and the inferior and superior caval vessels (IVC and SVC) were determined. Increasing airway pressure led to increases in ultrasonic surrogate parameters of right ventricular afterload, increasing transmural pressures in the right atrium and SVC, and a drop in transmural IVC pressure. SVV and PPV increased with increasing airway pressure, despite the increase in right atrial transmural pressure. Right ventricular stroke volume variation correlated with indicators of right ventricular afterload. This behavior was observed in both PEEP levels and all volume states. Stroke volume variation may reflect changes in right ventricular afterload rather than changes in preload.NEW & NOTEWORTHY Stroke volume variation and pulse pressure variation are used as indicators of preload or volume responsiveness of the heart. Our study shows that these variations are influenced by changes in right ventricular afterload and may therefore reflect right ventricular failure rather than pure volume responsiveness. A zone of collapse detaches the superior vena cava and its diameter variation from the right atrium.
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Affiliation(s)
- Elisa Valenti
- Department of Intensive Care Medicine, Inselspital University Hospital, University of Bern, Bern, Switzerland.,Intensive Care Unit and Department of Intensive Care, Ospedale Regionale di Lugano, Lugano, Switzerland
| | - Per W Moller
- Department of Anesthesiology and Intensive Care Medicine, Institute of Clinical Sciences at the Sahlgrenska Academy, University of Gothenburg, SV Hospital Group, Alingsas, Sweden
| | - Jukka Takala
- Department of Intensive Care Medicine, Inselspital University Hospital, University of Bern, Bern, Switzerland
| | - David Berger
- Department of Intensive Care Medicine, Inselspital University Hospital, University of Bern, Bern, Switzerland
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Hadfield DJ, Rose L, Reid F, Cornelius V, Hart N, Finney C, Penhaligon B, Molai J, Harris C, Saha S, Noble H, Clarey E, Thompson L, Smith J, Johnson L, Hopkins PA, Rafferty GF. Neurally adjusted ventilatory assist versus pressure support ventilation: a randomized controlled feasibility trial performed in patients at risk of prolonged mechanical ventilation. Crit Care 2020; 24:220. [PMID: 32408883 PMCID: PMC7224141 DOI: 10.1186/s13054-020-02923-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/24/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The clinical effectiveness of neurally adjusted ventilatory assist (NAVA) has yet to be demonstrated, and preliminary studies are required. The study aim was to assess the feasibility of a randomized controlled trial (RCT) of NAVA versus pressure support ventilation (PSV) in critically ill adults at risk of prolonged mechanical ventilation (MV). METHODS An open-label, parallel, feasibility RCT (n = 78) in four ICUs of one university-affiliated hospital. The primary outcome was mode adherence (percentage of time adherent to assigned mode), and protocol compliance (binary-≥ 65% mode adherence). Secondary exploratory outcomes included ventilator-free days (VFDs), sedation, and mortality. RESULTS In the 72 participants who commenced weaning, median (95% CI) mode adherence was 83.1% (64.0-97.1%) and 100% (100-100%), and protocol compliance was 66.7% (50.3-80.0%) and 100% (89.0-100.0%) in the NAVA and PSV groups respectively. Secondary outcomes indicated more VFDs to D28 (median difference 3.0 days, 95% CI 0.0-11.0; p = 0.04) and fewer in-hospital deaths (relative risk 0.5, 95% CI 0.2-0.9; p = 0.032) for NAVA. Although overall sedation was similar, Richmond Agitation and Sedation Scale (RASS) scores were closer to zero in NAVA compared to PSV (p = 0.020). No significant differences were observed in duration of MV, ICU or hospital stay, or ICU, D28, and D90 mortality. CONCLUSIONS This feasibility trial demonstrated good adherence to assigned ventilation mode and the ability to meet a priori protocol compliance criteria. Exploratory outcomes suggest some clinical benefit for NAVA compared to PSV. Clinical effectiveness trials of NAVA are potentially feasible and warranted. TRIAL REGISTRATION ClinicalTrials.gov, NCT01826890. Registered 9 April 2013.
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Affiliation(s)
- Daniel J Hadfield
- Critical Care, King's College Hospital, London, UK.
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.
| | - Louise Rose
- Florence Nightingale Faculty of Nursing, Midwifery & Palliative Care, King's College London, London, UK
- Sunnybrook Health Sciences Centre and Sunnybrook Research Institute, Toronto, Canada
| | - Fiona Reid
- School of Population Health and Environmental Sciences, King's College London, London, UK
| | - Victoria Cornelius
- Faculty of Medicine, School of Public Health, Imperial College, London, UK
| | - Nicholas Hart
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
- Lane Fox Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Clare Finney
- Critical Care, King's College Hospital, London, UK
| | | | | | - Clair Harris
- Critical Care, King's College Hospital, London, UK
| | - Sian Saha
- Critical Care, King's College Hospital, London, UK
| | | | - Emma Clarey
- Critical Care, King's College Hospital, London, UK
| | | | - John Smith
- Critical Care, King's College Hospital, London, UK
| | - Lucy Johnson
- Critical Care, King's College Hospital, London, UK
| | | | - Gerrard F Rafferty
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
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Skytioti M, Søvik S, Elstad M. Respiratory pump maintains cardiac stroke volume during hypovolemia in young, healthy volunteers. J Appl Physiol (1985) 2018; 124:1319-1325. [DOI: 10.1152/japplphysiol.01009.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Spontaneous breathing has beneficial effects on the circulation, since negative intrathoracic pressure enhances venous return and increases cardiac stroke volume. We quantified the contribution of the respiratory pump to preserve stroke volume during hypovolemia in awake, young, healthy subjects. Noninvasive stroke volume, cardiac output, heart rate, and mean arterial pressure (Finometer) were recorded in 31 volunteers (19 women), 19–30 yr old, during normovolemia and hypovolemia (approximating 450- to 500-ml reduction in central blood volume) induced by lower-body negative pressure. Control-mode noninvasive positive-pressure ventilation was employed to reduce the effect of the respiratory pump. The ventilator settings were matched to each subject’s spontaneous respiratory pattern. Stroke volume estimates during positive-pressure ventilation and spontaneous breathing were compared with Wilcoxon matched-pairs signed-rank test. Values are overall medians. During normovolemia, positive-pressure ventilation did not affect stroke volume or cardiac output. Hypovolemia resulted in an 18% decrease in stroke volume and a 9% decrease in cardiac output ( P < 0.001). Employing positive-pressure ventilation during hypovolemia decreased stroke volume further by 8% ( P < 0.001). Overall, hypovolemia and positive-pressure ventilation resulted in a reduction of 26% in stroke volume ( P < 0.001) and 13% in cardiac output ( P < 0.001) compared with baseline. Compared with the situation with control-mode positive-pressure ventilation, spontaneous breathing attenuated the reduction in stroke volume induced by moderate hypovolemia by 30% (i.e., −26 vs. −18%). In the patient who is critically ill with hypovolemia or uncontrolled hemorrhage, spontaneous breathing may contribute to hemodynamic stability, whereas controlled positive-pressure ventilation may result in circulatory decompensation. NEW & NOTEWORTHY Maintaining spontaneous respiration has beneficial effects on hemodynamic compensation, which is clinically relevant for patients in intensive care. We have quantified the contribution of the respiratory pump to cardiac stroke volume and cardiac output in healthy volunteers during normovolemia and central hypovolemia. The positive hemodynamic effect of the respiratory pump was abolished by noninvasive, low-level positive-pressure ventilation. Compared with control-mode positive-pressure ventilation, spontaneous negative-pressure ventilation attenuated the fall in stroke volume by 30%.
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Affiliation(s)
- Maria Skytioti
- Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Signe Søvik
- Department of Anaesthesia and Intensive Care, Akershus University Hospital, Lørenskog, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Maja Elstad
- Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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Sood SB, Mushtaq N, Brown K, Littlefield V, Barton RP. Neurally Adjusted Ventilatory Assist Is Associated with Greater Initial Extubation Success in Postoperative Congenital Heart Disease Patients when Compared to Conventional Mechanical Ventilation. J Pediatr Intensive Care 2018; 7:147-158. [PMID: 31073487 DOI: 10.1055/s-0038-1627099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/08/2017] [Indexed: 01/23/2023] Open
Abstract
Extubation failure is associated with considerable morbidity and mortality in postoperative patients with congenital heart disease (CHD). The study purpose was to investigate initial extubation success utilizing neurally adjusted ventilatory assist (NAVA) compared with pressure-regulated volume controlled, synchronized intermittent mandatory ventilation with pressure support (SIMV-PRVC + PS) for ventilatory weaning in patients who required prolonged mechanical ventilation (MV). Also, total days on MV, inotropes, sedation, analgesia, and pediatric intensive care unit (PICU) length of stay (LOS) between both groups were compared. This was a non-randomized pilot study utilizing historical controls (SIMV-PRVC + PS; n = 40) compared with a prospective study population (NAVA; n = 35) in a Level I PICU and was implemented to help future trial designs. All patients ( n = 75) required prolonged MV ≥96 hours due to their complex postoperative course. Ventilator weaning initiation and management was standardized between both groups. Ninety-seven percent of the NAVA group was successfully extubated on the initial attempt, while 80% were in the SIMV-PRVC + PS group ( p = 0.0317). Patients placed on NAVA were eight times more likely to have successful initial extubation (odds ratio [OR]: 8.50, 95% confidence interval [CI]: 1.01, 71.82). The NAVA group demonstrated a shorter median duration on MV (9.0 vs. 11.0 days, p = 0.032), PICU LOS (9.0 vs. 13.5 days, p < 0.0001), and shorter median duration of days on dopamine (8.0 vs. 11.0 days, p = 0.0022), milrinone (9.0 vs. 12.0 days, p = 0.0002), midazolam (8.0 vs. 12.0 days, p < 0.0001), and fentanyl (9.0 vs. 12.5 days, p < 0.0001) compared with the SIMV-PRVC + PS group. NAVA compared with SIMV-PRVC + PS was associated with a greater initial extubation success rate. NAVA should be considered as a mechanical ventilator weaning strategy in postoperative congenital heart disease (CHD) patients and warrants further investigation.
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Affiliation(s)
- Shawn Berry Sood
- Department of Pediatrics, University of Oklahoma School of Community Medicine, Tulsa, Oklahoma, United States
| | - Nasir Mushtaq
- Department of Pediatrics, University of Oklahoma School of Community Medicine, Tulsa, Oklahoma, United States
| | - Kellie Brown
- Division of Pediatric Intensive Care, The Children's Hospital at Saint Francis, 6161 South Yale Avenue, Tulsa, Oklahoma 74136, United States
| | - Vanette Littlefield
- Division of Pediatric Intensive Care, The Children's Hospital at Saint Francis, 6161 South Yale Avenue, Tulsa, Oklahoma 74136, United States
| | - Roger Phillip Barton
- Division of Pediatric Intensive Care, The Children's Hospital at Saint Francis, 6161 South Yale Avenue, Tulsa, Oklahoma 74136, United States
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10
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Abstract
Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear.
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11
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Berger D, Bloechlinger S, von Haehling S, Doehner W, Takala J, Z'Graggen WJ, Schefold JC. Dysfunction of respiratory muscles in critically ill patients on the intensive care unit. J Cachexia Sarcopenia Muscle 2016; 7:403-12. [PMID: 27030815 PMCID: PMC4788634 DOI: 10.1002/jcsm.12108] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 12/18/2015] [Accepted: 01/27/2016] [Indexed: 12/13/2022] Open
Abstract
Muscular weakness and muscle wasting may often be observed in critically ill patients on intensive care units (ICUs) and may present as failure to wean from mechanical ventilation. Importantly, mounting data demonstrate that mechanical ventilation itself may induce progressive dysfunction of the main respiratory muscle, i.e. the diaphragm. The respective condition was termed 'ventilator-induced diaphragmatic dysfunction' (VIDD) and should be distinguished from peripheral muscular weakness as observed in 'ICU-acquired weakness (ICU-AW)'. Interestingly, VIDD and ICU-AW may often be observed in critically ill patients with, e.g. severe sepsis or septic shock, and recent data demonstrate that the pathophysiology of these conditions may overlap. VIDD may mainly be characterized on a histopathological level as disuse muscular atrophy, and data demonstrate increased proteolysis and decreased protein synthesis as important underlying pathomechanisms. However, atrophy alone does not explain the observed loss of muscular force. When, e.g. isolated muscle strips are examined and force is normalized for cross-sectional fibre area, the loss is disproportionally larger than would be expected by atrophy alone. Nevertheless, although the exact molecular pathways for the induction of proteolytic systems remain incompletely understood, data now suggest that VIDD may also be triggered by mechanisms including decreased diaphragmatic blood flow or increased oxidative stress. Here we provide a concise review on the available literature on respiratory muscle weakness and VIDD in the critically ill. Potential underlying pathomechanisms will be discussed before the background of current diagnostic options. Furthermore, we will elucidate and speculate on potential novel future therapeutic avenues.
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Affiliation(s)
- David Berger
- Department of Intensive Care Medicine, Inselspital University Hospital of Bern Bern Switzerland
| | - Stefan Bloechlinger
- Department of Intensive Care Medicine, Inselspital University Hospital of Bern Bern Switzerland; Department of Clinical Cardiology, Inselspital University Hospital of Bern Bern Switzerland
| | - Stephan von Haehling
- Department of Cardiology and Center for Innovative Clinical Trials University of Göttingen Göttingen Germany
| | - Wolfram Doehner
- Center for Stroke Research Berlin Charite Universitätsmedizin Berlin Berlin Germany
| | - Jukka Takala
- Department of Intensive Care Medicine, Inselspital University Hospital of Bern Bern Switzerland
| | - Werner J Z'Graggen
- Department of Neurosurgery and Dept. of Neurology, Inselspital University Hospital of Bern Bern Switzerland
| | - Joerg C Schefold
- Department of Intensive Care Medicine, Inselspital University Hospital of Bern Bern Switzerland
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12
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Berger D, Moller PW, Weber A, Bloch A, Bloechlinger S, Haenggi M, Sondergaard S, Jakob SM, Magder S, Takala J. Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return. Am J Physiol Heart Circ Physiol 2016; 311:H794-806. [DOI: 10.1152/ajpheart.00931.2015] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 07/13/2016] [Indexed: 11/22/2022]
Abstract
According to Guyton's model of circulation, mean systemic filling pressure (MSFP), right atrial pressure (RAP), and resistance to venous return (RVR) determine venous return. MSFP has been estimated from inspiratory hold-induced changes in RAP and blood flow. We studied the effect of positive end-expiratory pressure (PEEP) and blood volume on venous return and MSFP in pigs. MSFP was measured by balloon occlusion of the right atrium (MSFPRAO), and the MSFP obtained via extrapolation of pressure-flow relationships with airway occlusion (MSFPinsp_hold) was extrapolated from RAP/pulmonary artery flow (QPA) relationships during inspiratory holds at PEEP 5 and 10 cmH2O, after bleeding, and in hypervolemia. MSFPRAO increased with PEEP [PEEP 5, 12.9 (SD 2.5) mmHg; PEEP 10, 14.0 (SD 2.6) mmHg, P = 0.002] without change in QPA [2.75 (SD 0.43) vs. 2.56 (SD 0.45) l/min, P = 0.094]. MSFPRAO decreased after bleeding and increased in hypervolemia [10.8 (SD 2.2) and 16.4 (SD 3.0) mmHg, respectively, P < 0.001], with parallel changes in QPA. Neither PEEP nor volume state altered RVR ( P = 0.489). MSFPinsp_hold overestimated MSFPRAO [16.5 (SD 5.8) vs. 13.6 (SD 3.2) mmHg, P = 0.001; mean difference 3.0 (SD 5.1) mmHg]. Inspiratory holds shifted the RAP/QPA relationship rightward in euvolemia because inferior vena cava flow (QIVC) recovered early after an inspiratory hold nadir. The QIVC nadir was lowest after bleeding [36% (SD 24%) of preinspiratory hold at 15 cmH2O inspiratory pressure], and the QIVC recovery was most complete at the lowest inspiratory pressures independent of volume state [range from 80% (SD 7%) after bleeding to 103% (SD 8%) at PEEP 10 cmH2O of QIVC before inspiratory hold]. The QIVC recovery thus defends venous return, possibly via hepatosplanchnic vascular waterfall.
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Affiliation(s)
- David Berger
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Per W. Moller
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences at the Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Alberto Weber
- Department of Cardiovascular Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Andreas Bloch
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Stefan Bloechlinger
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and
| | - Matthias Haenggi
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Soren Sondergaard
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences at the Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Stephan M. Jakob
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Sheldon Magder
- Department of Critical Care, McGill University Health Centre, Montreal, Quebec, Canada
| | - Jukka Takala
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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Lamia B, Molano LC, Muir JF, Cuvelier A. [Cardiopulmonary interactions in the course of mechanical ventilation]. Rev Mal Respir 2016; 33:865-876. [PMID: 26857198 DOI: 10.1016/j.rmr.2015.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 11/15/2015] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The haemodynamic consequences of ventilation are multiple and complex and may affect all the determinants of cardiac performance such as heart rate, preload, contractility and afterload. These consequences affect both right and left ventricle and are also related to the biventricular interdependence. STATE-OF-THE-ART Ventilation modifies the lung volume and also the intrathoracic pressure. Variations in lung volume have consequences on the pulmonary vascular resistance, hypoxic pulmonary vasoconstriction and ventricular interdependence. Variations in intrathoracic pressure have a major impact and affect systemic venous return, right ventricular preload, left ventricular preload, right ventricular afterload, left ventricular afterload and myocardial contracility. The haemodynamic consequences of positive pressure ventilation depend on the underlying chronic cardiopulmonary pathologies leading to the acute respiratory failure that was the indication for ventilation. CONCLUSION In this review, we will focus on severe COPD exacerbation, acute left heart failure and weaning from ventilation.
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Affiliation(s)
- B Lamia
- UPRES EA 3830, service de pneumologie et soins intensifs respiratoires, institut hospitalo-universitaire de recherche biomédicale et d'innovation, CHU de Rouen, université de Rouen, 76031 Rouen cedex, France.
| | - L-C Molano
- UPRES EA 3830, service de pneumologie et soins intensifs respiratoires, institut hospitalo-universitaire de recherche biomédicale et d'innovation, CHU de Rouen, université de Rouen, 76031 Rouen cedex, France
| | - J-F Muir
- UPRES EA 3830, service de pneumologie et soins intensifs respiratoires, institut hospitalo-universitaire de recherche biomédicale et d'innovation, CHU de Rouen, université de Rouen, 76031 Rouen cedex, France
| | - A Cuvelier
- UPRES EA 3830, service de pneumologie et soins intensifs respiratoires, institut hospitalo-universitaire de recherche biomédicale et d'innovation, CHU de Rouen, université de Rouen, 76031 Rouen cedex, France
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14
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Neurally adjusted ventilatory assist (NAVA) allows patient-ventilator synchrony during pediatric noninvasive ventilation: a crossover physiological study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:44. [PMID: 25886793 PMCID: PMC4342194 DOI: 10.1186/s13054-015-0770-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 01/23/2015] [Indexed: 11/16/2022]
Abstract
Introduction The need for intubation after a noninvasive ventilation (NIV) failure is frequent in the pediatric intensive care unit (PICU). One reason is patient-ventilator asynchrony during NIV. Neurally adjusted ventilatory assist (NAVA) is a mode of ventilation controlled by the patient’s neural respiratory drive. The aim of this study was to assess the feasibility and tolerance of NIV-NAVA in children and to evaluate its impact on synchrony and respiratory effort. Methods This prospective, physiologic, crossover study included 13 patients requiring NIV in the PICU of Sainte-Justine’s Hospital from October 2011 to May 2013. Patients were successively ventilated in conventional NIV as prescribed by the physician in charge (30 minutes), in NIV-NAVA (60 minutes), and again in conventional NIV (30 minutes). Electrical activity of the diaphragm (EAdi) and airway pressure were simultaneously recorded to assess patient-ventilator synchrony. Results NIV-NAVA was feasible and well tolerated in all patients. One patient asked to stop the study because of anxiety related to the leak-free facial mask. Inspiratory trigger dys-synchrony and cycling-off dys-synchrony were significantly shorter in NIV-NAVA versus initial and final conventional NIV periods (both P <0.05). Wasted efforts were also decreased in NIV-NAVA (all values expressed as median and interquartile values) (0 (0 to 0) versus 12% (4 to 20) and 6% (2 to 22), respectively; P <0.01). As a whole, total time spent in asynchrony was reduced to 8% (6 to 10) in NIV-NAVA, versus 27% (19 to 56) and 32% (21 to 38) in conventional NIV before and after NIV-NAVA, respectively (P =0.05). Conclusion NIV-NAVA is feasible and well tolerated in PICU patients and allows improved patient-ventilator synchronization. Larger controlled studies are warranted to evaluate the clinical impact of these findings. Trial registration ClinicalTrials.gov NCT02163382. Registered 9 June 2014.
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