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Stamatopoulou V, Akoumianaki E, Vaporidi K, Stamatopoulos E, Kondili E, Georgopoulos D. Driving pressure of respiratory system and lung stress in mechanically ventilated patients with active breathing. Crit Care 2024; 28:19. [PMID: 38217038 PMCID: PMC10785492 DOI: 10.1186/s13054-024-04797-3] [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: 11/10/2023] [Accepted: 01/03/2024] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND During control mechanical ventilation (CMV), the driving pressure of the respiratory system (ΔPrs) serves as a surrogate of transpulmonary driving pressure (ΔPlung). Expiratory muscle activity that decreases end-expiratory lung volume may impair the validity of ΔPrs to reflect ΔPlung. This prospective observational study in patients with acute respiratory distress syndrome (ARDS) ventilated with proportional assist ventilation (PAV+), aimed to investigate: (1) the prevalence of elevated ΔPlung, (2) the ΔPrs-ΔPlung relationship, and (3) whether dynamic transpulmonary pressure (Plungsw) and effort indices (transdiaphragmatic and respiratory muscle pressure swings) remain within safe limits. METHODS Thirty-one patients instrumented with esophageal and gastric catheters (n = 22) were switched from CMV to PAV+ and respiratory variables were recorded, over a maximum of 24 h. To decrease the contribution of random breaths with irregular characteristics, a 7-breath moving average technique was applied. In each patient, measurements were also analyzed per deciles of increasing lung elastance (Elung). Patients were divided into Group A, if end-inspiratory transpulmonary pressure (PLEI) increased as Elung increased, and Group B, which showed a decrease or no change in PLEI with Elung increase. RESULTS In 44,836 occluded breaths, ΔPlung ≥ 12 cmH2O was infrequently observed [0.0% (0.0-16.9%) of measurements]. End-expiratory lung volume decrease, due to active expiration, was associated with underestimation of ΔPlung by ΔPrs, as suggested by a negative linear relationship between transpulmonary pressure at end-expiration (PLEE) and ΔPlung/ΔPrs. Group A included 17 and Group B 14 patients. As Elung increased, ΔPlung increased mainly due to PLEI increase in Group A, and PLEE decrease in Group B. Although ΔPrs had an area receiver operating characteristic curve (AUC) of 0.87 (95% confidence intervals 0.82-0.92, P < 0.001) for ΔPlung ≥ 12 cmH2O, this was due exclusively to Group A [0.91 (0.86-0.95), P < 0.001]. In Group B, ΔPrs showed no predictive capacity for detecting ΔPlung ≥ 12 cmH2O [0.65 (0.52-0.78), P > 0.05]. Most of the time Plungsw and effort indices remained within safe range. CONCLUSION In patients with ARDS ventilated with PAV+, injurious tidal lung stress and effort were infrequent. In the presence of expiratory muscle activity, ΔPrs underestimated ΔPlung. This phenomenon limits the usefulness of ΔPrs as a surrogate of tidal lung stress, regardless of the mode of support.
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Affiliation(s)
- Vaia Stamatopoulou
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
| | - Evangelia Akoumianaki
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Katerina Vaporidi
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Efstathios Stamatopoulos
- Decision Support Systems, Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece
| | - Eumorfia Kondili
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Dimitrios Georgopoulos
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece.
- Medical School, University of Crete, Heraklion, Crete, Greece.
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Liu L, Li HL, Lu C, Patel P, Wang D, Beck J, Sinderby C. Estimation of transpulmonary driving pressure during synchronized mechanical ventilation using a single lower assist maneuver (LAM) in rabbits: a comparison to measurements made with an esophageal balloon. Crit Care 2023; 27:325. [PMID: 37626372 PMCID: PMC10463600 DOI: 10.1186/s13054-023-04607-2] [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: 04/17/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
BACKGROUND Mechanical ventilation is applied to unload the respiratory muscles, but knowledge about transpulmonary driving pressure (ΔPL) is important to minimize lung injury. We propose a method to estimate ΔPL during neurally synchronized assisted ventilation, with a simple intervention of lowering the assist for one breath ("lower assist maneuver", LAM). METHODS In 24 rabbits breathing spontaneously with imposed loads, titrations of increasing assist were performed, with two neurally synchronized modes: neurally adjusted ventilatory assist (NAVA) and neurally triggered pressure support (NPS). Two single LAM breaths (not sequentially, but independently) were performed at each level of assist by acutely setting the assist to zero cm H2O (NPS) or NAVA level 0 cm H2O/uV (NAVA) for one breath. NPS and NAVA titrations were followed by titrations in controlled-modes (volume control, VC and pressure control, PC), under neuro-muscular blockade. Breaths from the NAVA/NPS titrations were matched (for flow and volume) to VC or PC. Throughout all runs, we measured diaphragm electrical activity (Edi) and esophageal pressure (PES). We measured ΔPL during the spontaneous modes (PL_PES) and controlled mechanical ventilation (CMV) modes (PL_CMV) with the esophageal balloon. From the LAMs, we derived an estimation of ΔPL ("PL_LAM") using a correction factor (ratio of volume during the LAM and volume during assist) and compared it to measured ΔPL during passive (VC or PC) and spontaneous breathing (NAVA or NPS). A requirement for the LAM was similar Edi to the assisted breath. RESULTS All animals successfully underwent titrations and LAMs for NPS/NAVA. One thousand seven-hundred ninety-two (1792) breaths were matched to passive ventilation titrations (matched Vt, r = 0.99). PL_LAM demonstrated strong correlation with PL_CMV (r = 0.83), and PL_PES (r = 0.77). Bland-Altman analysis revealed little difference between the predicted PL_LAM and measured PL_CMV (Bias = 0.49 cm H2O and 1.96SD = 3.09 cm H2O). For PL_PES, the bias was 2.2 cm H2O and 1.96SD was 3.4 cm H2O. Analysis of Edi and PES at peak Edi showed progressively increasing uncoupling with increasing assist. CONCLUSION During synchronized mechanical ventilation, a LAM breath allows for estimations of transpulmonary driving pressure, without measuring PES, and follows a mathematical transfer function to describe respiratory muscle unloading during synchronized assist.
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Affiliation(s)
- Ling Liu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Hong-Liang Li
- Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Cong Lu
- Institute of Medical Science, University of Toronto, Toronto, Canada
- Department of Critical Care, St. Michael's Hospital, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada
| | - Purab Patel
- Department of Critical Care, St. Michael's Hospital, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada
| | - Danqiong Wang
- Department of Critical Care Medicine, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, China
| | - Jennifer Beck
- Department of Critical Care, St. Michael's Hospital, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada.
- Department of Pediatrics, University of Toronto, Toronto, Canada.
- Member, Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
| | - Christer Sinderby
- Department of Critical Care, St. Michael's Hospital, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada
- Member, Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada
- Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada
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Umbrello M, Antonucci E, Muttini S. Neurally Adjusted Ventilatory Assist in Acute Respiratory Failure-A Narrative Review. J Clin Med 2022; 11:jcm11071863. [PMID: 35407471 PMCID: PMC9000024 DOI: 10.3390/jcm11071863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/10/2022] [Accepted: 03/25/2022] [Indexed: 02/08/2023] Open
Abstract
Maintaining spontaneous breathing has both potentially beneficial and deleterious consequences in patients with acute respiratory failure, depending on the balance that can be obtained between the protecting and damaging effects on the lungs and the diaphragm. Neurally adjusted ventilatory assist (NAVA) is an assist mode, which supplies the respiratory system with a pressure proportional to the integral of the electrical activity of the diaphragm. This proportional mode of ventilation has the theoretical potential to deliver lung- and respiratory-muscle-protective ventilation by preserving the physiologic defense mechanisms against both lung overdistention and ventilator overassistance, as well as reducing the incidence of diaphragm disuse atrophy while maintaining patient–ventilator synchrony. This narrative review presents an overview of NAVA technology, its basic principles, the different methods to set the assist level and the findings of experimental and clinical studies which focused on lung and diaphragm protection, machine–patient interaction and preservation of breathing pattern variability. A summary of the findings of the available clinical trials which investigate the use of NAVA in acute respiratory failure will also be presented and discussed.
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Jonkman AH, Rauseo M, Carteaux G, Telias I, Sklar MC, Heunks L, Brochard LJ. Proportional modes of ventilation: technology to assist physiology. Intensive Care Med 2020; 46:2301-2313. [PMID: 32780167 PMCID: PMC7417783 DOI: 10.1007/s00134-020-06206-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 07/30/2020] [Indexed: 01/17/2023]
Abstract
Proportional modes of ventilation assist the patient by adapting to his/her effort, which contrasts with all other modes. The two proportional modes are referred to as neurally adjusted ventilatory assist (NAVA) and proportional assist ventilation with load-adjustable gain factors (PAV+): they deliver inspiratory assist in proportion to the patient’s effort, and hence directly respond to changes in ventilatory needs. Due to their working principles, NAVA and PAV+ have the ability to provide self-adjusted lung and diaphragm-protective ventilation. As these proportional modes differ from ‘classical’ modes such as pressure support ventilation (PSV), setting the inspiratory assist level is often puzzling for clinicians at the bedside as it is not based on usual parameters such as tidal volumes and PaCO2 targets. This paper provides an in-depth overview of the working principles of NAVA and PAV+ and the physiological differences with PSV. Understanding these differences is fundamental for applying any assisted mode at the bedside. We review different methods for setting inspiratory assist during NAVA and PAV+ , and (future) indices for monitoring of patient effort. Last, differences with automated modes are mentioned.
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Affiliation(s)
- Annemijn H Jonkman
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Room 4-08, Toronto, ON, M5B 1T8, Canada.,Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.,Department of Intensive Care Medicine, Amsterdam University Medical Centers, Location VUmc, Amsterdam, The Netherlands
| | - Michela Rauseo
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Room 4-08, Toronto, ON, M5B 1T8, Canada.,Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Guillaume Carteaux
- Assistance Publique-Hôpitaux de Paris, CHU Henri Mondor, Créteil, F-94010, France.,Groupe de Recherche Clinique CARMAS, Université Paris Est-Créteil, Créteil, F-94010, France.,Institut Mondor de Recherche Biomédicale INSERM 955, Créteil, F-94010, France
| | - Irene Telias
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Room 4-08, Toronto, ON, M5B 1T8, Canada.,Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Michael C Sklar
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Room 4-08, Toronto, ON, M5B 1T8, Canada.,Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada
| | - Leo Heunks
- Department of Intensive Care Medicine, Amsterdam University Medical Centers, Location VUmc, Amsterdam, The Netherlands
| | - Laurent J Brochard
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Room 4-08, Toronto, ON, M5B 1T8, Canada. .,Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.
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Standardized Unloading of Respiratory Muscles during Neurally Adjusted Ventilatory Assist: A Randomized Crossover Pilot Study. Anesthesiology 2019; 129:769-777. [PMID: 30045094 DOI: 10.1097/aln.0000000000002335] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
WHAT WE ALREADY KNOW ABOUT THIS TOPIC WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Currently, there is no standardized method to set the support level in neurally adjusted ventilatory assist (NAVA). The primary aim was to explore the feasibility of titrating NAVA to specific diaphragm unloading targets, based on the neuroventilatory efficiency (NVE) index. The secondary outcome was to investigate the effect of reduced diaphragm unloading on distribution of lung ventilation. METHODS This is a randomized crossover study between pressure support and NAVA at different diaphragm unloading at a single neurointensive care unit. Ten adult patients who had started weaning from mechanical ventilation completed the study. Two unloading targets were used: 40 and 60%. The NVE index was used to guide the titration of the assist in NAVA. Electrical impedance tomography data, blood-gas samples, and ventilatory parameters were collected. RESULTS The median unloading was 43% (interquartile range 32, 60) for 40% unloading target and 60% (interquartile range 47, 69) for 60% unloading target. NAVA with 40% unloading led to more dorsal ventilation (center of ventilation at 55% [51, 56]) compared with pressure support (52% [49, 56]; P = 0.019). No differences were found in oxygenation, CO2, and respiratory parameters. The electrical activity of the diaphragm was higher during NAVA with 40% unloading than in pressure support. CONCLUSIONS In this pilot study, NAVA could be titrated to different diaphragm unloading levels based on the NVE index. Less unloading was associated with greater diaphragm activity and improved ventilation of the dependent lung regions.
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Jonkman AH, Jansen D, Gadgil S, Keijzer C, Girbes ARJ, Scheffer GJ, van der Hoeven JG, Tuinman PR, Spoelstra-de Man AME, Sinderby CS, Heunks LMA. Monitoring patient-ventilator breath contribution in the critically ill during neurally adjusted ventilatory assist: reliability and improved algorithms for bedside use. J Appl Physiol (1985) 2019; 127:264-271. [PMID: 31161879 DOI: 10.1152/japplphysiol.00071.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The patient-ventilator breath contribution (PVBC) index estimates the relative contribution of the patient to total tidal volume (Vtinsp) during mechanical ventilation in neurally adjusted ventilator assist mode and has been used to titrate ventilator support. The reliability of this index in ventilated patients is unknown and was investigated in this study. PVBC was calculated by comparing tidal volume (Vtinsp) and diaphragm electrical activity (EAdi) during assisted breaths (Vtinsp/EAdi)assist and during unassisted breaths (Vtinsp/EAdi)no-assist. Vtinsp was normalized to peak EAdi (EAdipeak) using 1) one assisted breath, 2) five consecutive assisted breaths, or 3) five assisted breaths with matching EAdi preceding the unassisted breath (N1PVBC2, X5PVBC2, and PX5VBCEAdi-matching2 , respectively). In addition, PVBC was calculated by comparing only Vtinsp for breaths with matching EAdi (PVBCβ2). Test-retest reliability of the different PVBC calculation methods was evaluated with the intraclass correlation coefficient (ICC) using five repeated PVBC maneuvers performed with a 1-min interval. In total, 125 PVBC maneuvers were analyzed in 25 patients. ICC [95% confidence interval] values were 0.46 [0.23-0.66], 0.51 [0.33-0.70], and 0.42 [0.14-0.69] for N1PVBC2, X5PVBC2, PX5VBCEAdi-matching2 , respectively. Complex waveform analyses showed that insufficient EAdi filtering by the ventilator software affects reliability of PVBC calculation. With our new EAdi-matching techniques reliability improved (PVBCβ2 ICC: 0.78 [0.60-0.90]). We conclude that current techniques to calculate PVBC exhibit low reliability and that our newly developed criteria and estimation of PVBC-using Vtinsp of assisted breaths and unassisted breaths with matching EAdi-improves reliability. This may help implementation of PVBC in clinical practice. NEW & NOTEWORTHY The patient-ventilator breath contribution (PVBC) index estimates the relative contribution of the patient to tidal volume generated by the patient and the mechanical ventilator during mechanical ventilation in neurally adjusted ventilator assist mode. It could be used to titrate ventilator support and thus to limit development of diaphragm dysfunction in intensive care unit patients. Currently available methods for bedside assessment of PVBC are unreliable. Our newly developed criteria and estimation of PVBC largely improve reliability and help to quantify patient contribution to total inspiratory effort.
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Affiliation(s)
- Annemijn H Jonkman
- Department of Intensive Care Medicine, Amsterdam UMC, location VUmc, Amsterdam , The Netherlands
| | - Diana Jansen
- Department of Anesthesiology, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Suvarna Gadgil
- Department of Anesthesiology, University Medical Center Utrecht , Utrecht , The Netherlands
| | - Christiaan Keijzer
- Department of Anesthesiology, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Armand R J Girbes
- Department of Intensive Care Medicine, Amsterdam UMC, location VUmc, Amsterdam , The Netherlands
| | - Gert-Jan Scheffer
- Department of Anesthesiology, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Johannes G van der Hoeven
- Department of Intensive Care Medicine, Radboud University Medical Center , Nijmegen , The Netherlands
| | - Pieter Roel Tuinman
- Department of Intensive Care Medicine, Amsterdam UMC, location VUmc, Amsterdam , The Netherlands
| | | | - Christer S Sinderby
- Department of Critical Care Medicine, St. Michael's Hospital, University of Toronto , Toronto, Ontario , Canada
| | - Leo M A Heunks
- Department of Intensive Care Medicine, Amsterdam UMC, location VUmc, Amsterdam , The Netherlands
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Vaporidi K, Psarologakis C, Proklou A, Pediaditis E, Akoumianaki E, Koutsiana E, Chytas A, Chouvarda I, Kondili E, Georgopoulos D. Driving pressure during proportional assist ventilation: an observational study. Ann Intensive Care 2019; 9:1. [PMID: 30603960 PMCID: PMC6314935 DOI: 10.1186/s13613-018-0477-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/21/2018] [Indexed: 01/01/2023] Open
Abstract
Background During passive mechanical ventilation, the driving pressure of the respiratory system is an important mediator of ventilator-induced lung injury. Monitoring of driving pressure during assisted ventilation, similar to controlled ventilation, could be a tool to identify patients at risk of ventilator-induced lung injury. The aim of this study was to describe driving pressure over time and to identify whether and when high driving pressure occurs in critically ill patients during assisted ventilation. Methods Sixty-two patients fulfilling criteria for assisted ventilation were prospectively studied. Patients were included when the treating physician selected proportional assist ventilation (PAV+), a mode that estimates respiratory system compliance. In these patients, continuous recordings of all ventilator parameters were obtained for up to 72 h. Driving pressure was calculated as tidal volume-to-respiratory system compliance ratio. The distribution of driving pressure and tidal volume values over time was examined, and periods of sustained high driving pressure (≥ 15 cmH2O) and of stable compliance were identified and analyzed. Results The analysis included 3200 h of ventilation, consisting of 8.8 million samples. For most (95%) of the time, driving pressure was < 15 cmH2O and tidal volume < 11 mL/kg (of ideal body weight). In most patients, high driving pressure was observed for short periods of time (median 2.5 min). Prolonged periods of high driving pressure were observed in five patients (8%). During the 661 periods of stable compliance, high driving pressure combined with a tidal volume ≥ 8 mL/kg was observed only in 11 cases (1.6%) pertaining to four patients. High driving pressure occurred almost exclusively when respiratory system compliance was low, and compliance above 30 mL/cmH2O excluded the presence of high driving pressure with 90% sensitivity and specificity. Conclusions In critically ill patients fulfilling criteria for assisted ventilation, and ventilated in PAV+ mode, sustained high driving pressure occurred in a small, yet not negligible number of patients. The presence of sustained high driving pressure was not associated with high tidal volume, but occurred almost exclusively when compliance was below 30 mL/cmH2O. Electronic supplementary material The online version of this article (10.1186/s13613-018-0477-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katerina Vaporidi
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece
| | - Charalambos Psarologakis
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece
| | - Athanasia Proklou
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece
| | - Emmanouil Pediaditis
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece
| | - Evangelia Akoumianaki
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece
| | - Elisavet Koutsiana
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece.,Lab of Computing Medical Informatics and Biomedical Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Achilleas Chytas
- Lab of Computing Medical Informatics and Biomedical Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece.,Institute of Applied Biosciences, CERTH, Thessaloniki, Greece
| | - Ioanna Chouvarda
- Lab of Computing Medical Informatics and Biomedical Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece.,Institute of Applied Biosciences, CERTH, Thessaloniki, Greece
| | - Eumorfia Kondili
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece
| | - Dimitris Georgopoulos
- Department of Intensive Care Medicine, University Hospital of Heraklion, School of Medicine, University of Crete, Voutes, 71110, Heraklion, Crete, Greece.
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de Vries H, Jonkman A, Shi ZH, Spoelstra-de Man A, Heunks L. Assessing breathing effort in mechanical ventilation: physiology and clinical implications. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:387. [PMID: 30460261 DOI: 10.21037/atm.2018.05.53] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recent studies have shown both beneficial and detrimental effects of patient breathing effort in mechanical ventilation. Quantification of breathing effort may allow the clinician to titrate ventilator support to physiological levels of respiratory muscle activity. In this review we will describe the physiological background and methodological issues of the most frequently used methods to quantify breathing effort, including esophageal pressure measurement, the work of breathing, the pressure-time-product, electromyography and ultrasound. We will also discuss the level of breathing effort that may be considered optimal during mechanical ventilation at different stages of critical illness.
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Affiliation(s)
- Heder de Vries
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
| | - Annemijn Jonkman
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
| | - Zhong-Hua Shi
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands.,Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Angélique Spoelstra-de Man
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
| | - Leo Heunks
- Department of Intensive Care Medicine, Amsterdam Cardiovascular Sciences, VU University Medical Centre, Amsterdam, The Netherlands
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Jansen D, Jonkman AH, Roesthuis L, Gadgil S, van der Hoeven JG, Scheffer GJJ, Girbes A, Doorduin J, Sinderby CS, Heunks LMA. Estimation of the diaphragm neuromuscular efficiency index in mechanically ventilated critically ill patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:238. [PMID: 30261920 PMCID: PMC6161422 DOI: 10.1186/s13054-018-2172-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/28/2018] [Indexed: 12/27/2022]
Abstract
Background Diaphragm dysfunction develops frequently in ventilated intensive care unit (ICU) patients. Both disuse atrophy (ventilator over-assist) and high respiratory muscle effort (ventilator under-assist) seem to be involved. A strong rationale exists to monitor diaphragm effort and titrate support to maintain respiratory muscle activity within physiological limits. Diaphragm electromyography is used to quantify breathing effort and has been correlated with transdiaphragmatic pressure and esophageal pressure. The neuromuscular efficiency index (NME) can be used to estimate inspiratory effort, however its repeatability has not been investigated yet. Our goal is to evaluate NME repeatability during an end-expiratory occlusion (NMEoccl) and its use to estimate the pressure generated by the inspiratory muscles (Pmus). Methods This is a prospective cohort study, performed in a medical-surgical ICU. A total of 31 adult patients were included, all ventilated in neurally adjusted ventilator assist (NAVA) mode with an electrical activity of the diaphragm (EAdi) catheter in situ. At four time points within 72 h five repeated end-expiratory occlusion maneuvers were performed. NMEoccl was calculated by delta airway pressure (ΔPaw)/ΔEAdi and was used to estimate Pmus. The repeatability coefficient (RC) was calculated to investigate the NMEoccl variability. Results A total number of 459 maneuvers were obtained. At time T = 0 mean NMEoccl was 1.22 ± 0.86 cmH2O/μV with a RC of 82.6%. This implies that when NMEoccl is 1.22 cmH2O/μV, it is expected with a probability of 95% that the subsequent measured NMEoccl will be between 2.22 and 0.22 cmH2O/μV. Additional EAdi waveform analysis to correct for non-physiological appearing waveforms, did not improve NMEoccl variability. Selecting three out of five occlusions with the lowest variability reduced the RC to 29.8%. Conclusions Repeated measurements of NMEoccl exhibit high variability, limiting the ability of a single NMEoccl maneuver to estimate neuromuscular efficiency and therefore the pressure generated by the inspiratory muscles based on EAdi. Electronic supplementary material The online version of this article (10.1186/s13054-018-2172-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Diana Jansen
- Department of Anesthesiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Annemijn H Jonkman
- Department of Intensive Care Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Postbox 7057, 1007, MB, Amsterdam, The Netherlands
| | - Lisanne Roesthuis
- Department of Intensive Care Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Suvarna Gadgil
- Department of Anesthesiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Gert-Jan J Scheffer
- Department of Anesthesiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Armand Girbes
- Department of Intensive Care Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Postbox 7057, 1007, MB, Amsterdam, The Netherlands
| | - Jonne Doorduin
- Department of Neurology, Donders Institute, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christer S Sinderby
- Department of Critical Care Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada
| | - Leo M A Heunks
- Department of Intensive Care Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Postbox 7057, 1007, MB, Amsterdam, The Netherlands.
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Brander L, Moerer O, Hedenstierna G, Beck J, Takala J, Slutsky AS, Sinderby C. Neural control of ventilation prevents both over-distension and de-recruitment of experimentally injured lungs. Respir Physiol Neurobiol 2016; 237:57-67. [PMID: 28013057 DOI: 10.1016/j.resp.2016.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/25/2016] [Accepted: 12/20/2016] [Indexed: 01/24/2023]
Abstract
BACKGROUND Endogenous pulmonary reflexes may protect the lungs during mechanical ventilation. We aimed to assess integration of continuous neurally adjusted ventilatory assist (cNAVA), delivering assist in proportion to diaphragm's electrical activity during inspiration and expiration, and Hering-Breuer inflation and deflation reflexes on lung recruitment, distension, and aeration before and after acute lung injury (ALI). METHODS In 7 anesthetised rabbits with bilateral pneumothoraces, we identified adequate cNAVA level (cNAVAAL) at the plateau in peak ventilator pressure during titration procedures before (healthy lungs with endotracheal tube, [HLETT]) and after ALI (endotracheal tube [ALIETT] and during non-invasive ventilation [ALINIV]). Following titration, cNAVAAL was maintained for 5min. In 2 rabbits, procedures were repeated after vagotomy (ALIETT+VAG). In 3 rabbits delivery of assist was temporarily modulated to provide assist on inspiration only. Computed tomography was performed before intubation, before ALI, during cNAVA titration, and after maintenance at cNAVAAL. RESULTS During ALIETT and ALINIV, normally aerated lung-regions doubled and poorly aerated lung-regions decreased to less than a third (p<0.05) compared to HLETT; no over-distension was observed. Tidal volumes were<5ml/kg throughout. Removing assist during expiration resulted in lung de-recruitment during ALIETT, but not during ALINIV. During ALIETT+VAG the expiratory portion of EAdi disappeared, resulting in cyclic lung collapse and recruitment. CONCLUSIONS When using cNAVA in ALI, vagally mediated reflexes regulated lung recruitment preventing both lung over-distension and atelectasis. During non-invasive cNAVA the upper airway muscles play a role in preventing atelectasis. Future studies should be performed to compare these findings with conventional lung-protective approaches.
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Affiliation(s)
- Lukas Brander
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Department of Critical Care Medicine, St. Michael's Hospital, Toronto, Canada; Department of Intensive Care Medicine, Cantonal Hospital of Lucerne, Switzerland.
| | - Onnen Moerer
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Department of Critical Care Medicine, St. Michael's Hospital, Toronto, Canada; Department of Anaesthesiology, Emergency and Critical Care Medicine, University of Göttingen, Germany
| | - Göran Hedenstierna
- Department of Medical Sciences, Clinical Physiology, University of Uppsala, Uppsala, Sweden
| | - Jennifer Beck
- Department of Pediatrics, University of Toronto, Toronto, Canada; Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada; Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St. Michael's Hospital, Toronto, Canada
| | - Jukka Takala
- Department of Intensive Care Medicine, Bern University Hospital - Inselspital, and University of Bern, Switzerland
| | - Arthur S Slutsky
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Department of Critical Care Medicine, St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada
| | - Christer Sinderby
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Department of Critical Care Medicine, St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada; Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St. Michael's Hospital, Toronto, Canada
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11
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Zhu L, Xu Z, Gong X, Zheng J, Sun Y, Liu L, Han L, Zhang H, Xu Z, Liu J, Rimensberger PC. Mechanical Ventilation After Bidirectional Superior Cavopulmonary Anastomosis for Single-Ventricle Physiology: A Comparison of Pressure Support Ventilation and Neurally Adjusted Ventilatory Assist. Pediatr Cardiol 2016; 37:1064-71. [PMID: 27090649 DOI: 10.1007/s00246-016-1392-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 04/05/2016] [Indexed: 11/29/2022]
Abstract
We evaluated the effects of different respiratory assist modes on cerebral blood flow (CBF) and arterial oxygenation in single-ventricle patients after bidirectional superior cavopulmonary anastomosis (BCPA). We hypothesized that preserved auto-regulation of respiration during neurally adjusted ventilatory assist (NAVA) may have potential advantages for CBF and pulmonary blood flow regulation after the BCPA procedure. We enrolled 23 patients scheduled for BCPA, who underwent pressure-controlled ventilation (PCV), pressure support ventilation (PSV), and NAVA at two assist levels for all modes in a randomized order. PCV targeting large V T (15 mL × kg(-1)) resulted in lower CBF and oxygenation compared to targeting low V T (10 mL × kg(-1)). During PSV and NAVA, ventilation assist levels were titrated to reduce EAdi from baseline by 75 % (high assist) and 50 % (low assist). High assist levels during PSV (PSVhigh) were associated with lower PaCO2, PaO2, and O2SAT, lower CBF, and higher pulsatility index compared with those during NAVAhigh. There were no differences in parameters when using low assist levels, except for slightly greater oxygenation in the NAVAlow group. Modifying assist levels during NAVA did not influence hemodynamics, cerebral perfusion, or gas exchange. Targeting the larger V T during PCV resulted in hyperventilation, did not improve oxygenation, and was accompanied by reduced CBF. Similarly, high assist levels during PSV led to mild hyperventilation, resulting in reduced CBF. NAVA's results were independent of the assist level chosen, causing normalized PaCO2, improved oxygenation, and better CBF than did any other mode, with the exception of PSV at low assist levels.
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Affiliation(s)
- Limin Zhu
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China.
| | - Zhuoming Xu
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Xiaolei Gong
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Jinghao Zheng
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Yanjun Sun
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Liping Liu
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Lu Han
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Haibo Zhang
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Zhiwei Xu
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Jinfen Liu
- Cardiac Intensive Care Unit, Department of Cardiovascular and Thoracic Surgery, Shanghai Children's Medical Center, Medical School of Shanghai Jiaotong University, Shanghai, 200127, China
| | - Peter C Rimensberger
- Pediatric and Neonatal Intensive Care Unit, Department of Pediatrics, University Hospital of Geneva, Geneva, Switzerland
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12
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Liu L, Takahashi D, Qui H, Slutsky AS, Sinderby C, Beck J. Feasibility of neurally adjusted positive end-expiratory pressure in rabbits with early experimental lung injury. BMC Anesthesiol 2015; 15:124. [PMID: 26369672 PMCID: PMC4570554 DOI: 10.1186/s12871-015-0103-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 09/07/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During conventional Neurally Adjusted Ventilatory Assist (NAVA), the electrical activity of the diaphragm (EAdi) is used for triggering and cycling-off inspiratory assist, with a fixed PEEP (so called "Triggered Neurally Adjusted Ventilatory Assist" or "tNAVA"). However, significant post-inspiratory activity of the diaphragm can occur, believed to play a role in maintaining end-expiratory lung volume. Adjusting pressure continuously, in proportion to both inspiratory and expiratory EAdi (Continuous NAVA, or cNAVA), would not only offer inspiratory assist for tidal breathing, but also may aid in delivering a "neurally adjusted PEEP", and more specific breath-by-breath unloading. METHODS Nine adult New Zealand white rabbits were ventilated during independent conditions of: resistive loading (RES(1) or RES(2)), CO2 load (CO2) and acute lung injury (ALI), either via tracheotomy (INV) or non-invasively (NIV). There were a total of six conditions, applied in a non-randomized fashion: INV-RES(1), INV-CO2, NIV-CO2, NIV-RES(2), NIV-ALI, INV-ALI. For each condition, tNAVA was applied first (3 min), followed by 3 min of cNAVA. This comparison was repeated 3 times (repeated cross-over design). The NAVA level was always the same for both modes, but was newly titrated for each condition. PEEP was manually set to zero during tNAVA. During cNAVA, the assist during expiration was proportional to the EAdi. During all runs and conditions, ventilator-delivered pressure (Pvent), esophageal pressure (Pes), and diaphragm electrical activity (EAdi) were measured continuously. The tracings were analyzed breath-by-breath to obtain peak inspiratory and mean expiratory values. RESULTS For the same peak Pvent, the distribution of inspiratory and expiratory pressure differed between tNAVA and cNAVA. For each condition, the mean expiratory Pvent was always higher (for all conditions 4.0 ± 1.1 vs. 1.1 ± 0.5 cmH2O, P < 0.01) in cNAVA than in tNAVA. Relative to tNAVA, mean inspiratory EAdi was reduced on average (for all conditions) by 19 % (range 14 %-25 %), p < 0.05. Mean expiratory EAdi was also lower during cNAVA (during INV-RES(1), INV-CO2, INV-ALI, NIV-CO2 and NIV-ALI respectively, P < 0.05). The inspiratory Pes was reduced during cNAVA all 6 conditions (p < 0.05). Unlike tNAVA, during cNAVA the expiratory pressure was comparable with that predicted mathematically (mean difference of 0.2 ± 0.8 cmH2O). CONCLUSION Continuous NAVA was able to apply neurally adjusted PEEP, which led to a reduction in inspiratory effort compared to triggered NAVA.
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Affiliation(s)
- Ling Liu
- Department of Critical Care Medicine, Nanjing Zhong-Da Hospital, Southeast University School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Daijiro Takahashi
- Division of Pediatrics, Fukuda Hospital, 2-2-6, Shinmachi, Chuou-ku, Kumamoto city, 860-0004, Japan.
| | - Haibo Qui
- Department of Critical Care Medicine, Nanjing Zhong-Da Hospital, Southeast University School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Arthur S Slutsky
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital; Department of Critical Care, St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B1W8. .,Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada.
| | - Christer Sinderby
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital; Department of Critical Care, St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B1W8. .,Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada. .,Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
| | - Jennifer Beck
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital; Department of Critical Care, St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B1W8. .,Department of Pediatrics, University of Toronto, Toronto, Canada. .,Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
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13
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Kallio M, Peltoniemi O, Anttila E, Jounio U, Pokka T, Kontiokari T. Electrical activity of the diaphragm during neurally adjusted ventilatory assist in pediatric patients. Pediatr Pulmonol 2015; 50:925-31. [PMID: 25103680 DOI: 10.1002/ppul.23084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/15/2014] [Accepted: 05/22/2014] [Indexed: 11/05/2022]
Abstract
BACKGROUND Neurally adjusted ventilatory assist (NAVA) is a ventilation mode which provides respiratory support proportional to the electrical activity of the diaphragm (Edi). The aims of this trial were to assess the feasibility of aiming at peak Edi between 5 and 15 µV during NAVA in clinical practice, to study the effect of age, sedation level and ventilatory settings on the Edi signal and to give some reference values for Edi in a pediatric population. METHODS As a part of a larger randomized controlled trial, 81 patients received Edi catheter for monitoring Edi and guiding NAVA ventilation. The goal for peak Edi during invasive ventilation was 5-15 µV. Edi activity and NAVA levels were observed during invasive ventilation and an hour after extubation. RESULTS Sixty-six patients with healthy lungs (81.5%) were ventilated, mostly as part of postoperative care, while respiratory distress was the indication for invasive ventilation in the remaining 15 patients (18.5%). NAVA levels varied from 0.2 to 2.0 cmH2O/µV in the patients with healthy lungs, but were higher, from 0.7 to 4.0 cmH2O/µV, in the respiratory distress patients (P < 0.001). The latter had higher peak Edi values in all phases of treatment. The effect of age and level of sedation on Edi was statistically significant, but carried only limited clinical relevance. The peak post-extubation Edi levels of the patients with healthy lungs and respiratory distress, respectively, were 9 ± 7 and 20 ± 14 µV. Two out of the three patients for whom extubation failed had an atypical Edi pattern prior to extubation. CONCLUSIONS Optimizing the level of support during NAVA by aiming at a peak Edi between 5 and 15 µV was an applicable strategy in our pediatric population. Relatively high post-extubation Edi signal levels were seen in patients recovering from respiratory distress. Information revealed by the Edi signal could be used to find patients with a potential risk of extubation failure.
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Affiliation(s)
- Merja Kallio
- Department of Pediatrics, Oulu University Hospital, Oulu, Finland
| | - Outi Peltoniemi
- Department of Pediatrics, Oulu University Hospital, Oulu, Finland
| | - Eija Anttila
- Department of Pediatrics, Oulu University Hospital, Oulu, Finland
| | - Ulla Jounio
- Department of Pediatrics, Oulu University Hospital, Oulu, Finland
| | - Tytti Pokka
- Department of Pediatrics, Oulu University Hospital, Oulu, Finland
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14
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Abstract
Purpose of review The present review summarizes developments in the field of respiratory muscle monitoring, in particular in critically ill patients. Recent findings Patients admitted to the ICU may develop severe respiratory muscle dysfunction in a very short time span. Among other factors, disuse and sepsis have been associated with respiratory muscle dysfunction in these patients. Because weakness is associated with adverse outcome, including prolonged mechanical ventilation and mortality, it is surprising that respiratory muscle dysfunction largely develops without being noticed by the clinician. Respiratory muscle monitoring is not standard of care in most ICUs. Improvements in technology have opened windows for monitoring the respiratory muscles in critically ill patients. Diaphragm electromyography and esophageal pressure measurement are feasible techniques for respiratory muscle monitoring, although the effect on outcome remains to be investigated. Summary Respiratory muscle dysfunction develops rapidly in selected critically ill patients and is associated with adverse outcome. Recent technological advances allow real-time monitoring of respiratory muscle activity in these patients. Although this field is in its infancy, from a physiological perspective, it is reasonable to assume that monitoring respiratory muscle activity improves outcome in these patients.
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15
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Liu L, Xia F, Yang Y, Longhini F, Navalesi P, Beck J, Sinderby C, Qiu H. Neural versus pneumatic control of pressure support in patients with chronic obstructive pulmonary diseases at different levels of positive end expiratory pressure: a physiological study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:244. [PMID: 26059238 PMCID: PMC4487968 DOI: 10.1186/s13054-015-0971-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 06/01/2015] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Intrinsic positive end-expiratory pressure (PEEPi) is a "threshold" load that must be overcome to trigger conventional pneumatically-controlled pressure support (PSP) in chronic obstructive pulmonary disease (COPD). Application of extrinsic PEEP (PEEPe) reduces trigger delays and mechanical inspiratory efforts. Using the diaphragm electrical activity (EAdi), neurally controlled pressure support (PSN) could hypothetically eliminate asynchrony and reduce mechanical inspiratory effort, hence substituting the need for PEEPe. The primary objective of this study was to show that PSN can reduce the need for PEEPe to improve patient-ventilator interaction and to reduce both the "pre-trigger" and "total inspiratory" neural and mechanical efforts in COPD patients with PEEPi. A secondary objective was to evaluate the impact of applying PSN on breathing pattern. METHODS Twelve intubated and mechanically ventilated COPD patients with PEEPi ≥ 5 cm H2O underwent comparisons of PSP and PSN at different levels of PEEPe (at 0 %, 40 %, 80 %, and 120 % of static PEEPi, for 12 minutes at each level on average), at matching peak airway pressure. We measured flow, airway pressure, esophageal pressure, and EAdi, and analyzed neural and mechanical efforts for triggering and total inspiration. Patient-ventilator interaction was analyzed with the NeuroSync index. RESULTS Mean airway pressure and PEEPe were comparable for PSP and PSN at same target levels. During PSP, the NeuroSync index was 29 % at zero PEEPe and improved to 21 % at optimal PEEPe (P < 0.05). During PSN, the NeuroSync index was lower (<7 %, P < 0.05) regardless of PEEPe. Both pre-trigger (P < 0.05) and total inspiratory mechanical efforts (P < 0.05) were consistently higher during PSP compared to PSN at same PEEPe. The change in total mechanical efforts between PSP at PEEPe0% and PSN at PEEPe0% was not different from the change between PSP at PEEPe0% and PSP at PEEPe80%. CONCLUSION PSN abolishes the need for PEEPe in COPD patients, improves patient-ventilator interaction, and reduces the inspiratory mechanical effort to breathe. TRIAL REGISTRATION Clinicaltrials.gov NCT02114567 . Registered 04 November 2013.
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Affiliation(s)
- Ling Liu
- Department of Critical Care Medicine, Nanjing Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Feiping Xia
- Department of Critical Care Medicine, Nanjing Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Yi Yang
- Department of Critical Care Medicine, Nanjing Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Federico Longhini
- Department of Critical Care Medicine, Nanjing Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China. .,Department of Translational Medicine, Eastern Piedmont University "A. Avogadro", Novara, Italy.
| | - Paolo Navalesi
- Department of Translational Medicine, Eastern Piedmont University "A. Avogadro", Novara, Italy. .,Anaesthesia and Intensive Care, Sant'Andrea Hospital, ASL VC, Vercelli, Italy. .,CRRF Mons. L. Novarese, Moncrivello, VC, Italy.
| | - Jennifer Beck
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada. .,Department of Pediatrics, University of Toronto, Toronto, Ontario, M5G 1X8, Canada. .,Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
| | - Christer Sinderby
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada. .,Department of Medicine, University of Toronto, Toronto, Ontario, Canada. .,Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
| | - Haibo Qiu
- Department of Critical Care Medicine, Nanjing Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
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16
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Liu L, Liu S, Xie J, Yang Y, Slutsky AS, Beck J, Sinderby C, Qiu H. Assessment of patient-ventilator breath contribution during neurally adjusted ventilatory assist in patients with acute respiratory failure. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:43. [PMID: 25882607 PMCID: PMC4339109 DOI: 10.1186/s13054-015-0775-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 01/07/2015] [Indexed: 12/18/2022]
Abstract
INTRODUCTION We previously showed in animals that the ratio of inspired tidal volume (Vtinsp) to inspiratory peak electrical activity of the diaphragm (EAdipk) can be used to quantify the respective patient and ventilator breath contributions (PVBCs) during neurally adjusted ventilatory assist (NAVA). The PVBC index has not been tested clinically. METHODS We studied 12 intubated and mechanically ventilated patients with acute respiratory failure and measured EAdipk, airway (Paw) and inspiratory esophageal pressure (Pes) and Vtinsp. We applied 11 different NAVA levels, increasing them every 3 minutes in steps of 0.3 cm H₂O/μV from 0 to 3.0 cmH₂O/μV. At each NAVA level, one breath was non-assisted (NAVA level 0). PVBC indices were calculated by relating Vtinsp/EAdipk of the non-assisted breath to Vtinsp/EAdipk of the assisted breath(s) using one ((N1)PVBC) or the mean value of five preceding assisted breaths ((X5)PVBC). During assisted breaths, inspiratory changes in Pes (∆Pes) and transpulmonary (ΔPtp) pressures were used to calculate the relative contribution of patient to total inspiratory lung-distending pressures (ΔPes/ΔPtp). Matching of respiratory drive indices and squaring of the PVBC was evaluated for their effect on the correlation between PVBC and ΔPes/ΔPtp. Linear regression analysis and Bland-Altman analysis were applied to compare indices. RESULTS Using an average of five assisted breaths prior to the non-assisted breath and squaring the PVBC ((X5)PVBC(2)) improved determination coefficients (P <0.05), adjusted the regression slope and intercept between PVBC and ΔPes/ΔPtp toward identity (P <0.05) and reduced bias (P <0.05). Matching EAdipk between non-assisted and assisted breaths within the range of 0.77 to 1.30 improved the relationship between (X5)PVBC(2) and ΔPes/ΔPtp (P <0.05) and abolished the need for EAdi normalization in the PVBC calculation (R(2) = 0.96; bias = 0.16 ± 0.06; precision = 0.33 ± 0.08 (mean and 95% confidence interval)). CONCLUSIONS This clinical study confirms previous experimental results showing that the PVBC(2) predicts the contribution of the inspiratory muscles versus that of the ventilator during NAVA, when differences in effort (EAdi) between non-assisted and assisted breaths are limited. PVBC could help to quantify and standardize the adjustment of the level of assist, and hence reduce the risks of excessive ventilatory assist in patients. TRIAL REGISTRATION ClinicalTrials.gov NCT01663480. Registered 9 August 2012.
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Affiliation(s)
- Ling Liu
- Department of Critical Care Medicine, Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Songqiao Liu
- Department of Critical Care Medicine, Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Jianfeng Xie
- Department of Critical Care Medicine, Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Yi Yang
- Department of Critical Care Medicine, Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Arthur S Slutsky
- Keenan Research Centre for Biomedical Science and Department of Critical Care, St Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada. .,Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Suit RFE3-805, 200 Elizabeth Street, Toronto, ON, M5G 2C4, Canada.
| | - Jennifer Beck
- Keenan Research Centre for Biomedical Science and Department of Critical Care, St Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada. .,Department of Pediatrics, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
| | - Christer Sinderby
- Keenan Research Centre for Biomedical Science and Department of Critical Care, St Michael's Hospital, 30 Bond Street, Toronto, ON, M5B1W8, Canada. .,Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Suit RFE3-805, 200 Elizabeth Street, Toronto, ON, M5G 2C4, Canada.
| | - Haibo Qiu
- Department of Critical Care Medicine, Zhongda Hospital, Southeast University, School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
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Abstract
PURPOSE OF REVIEW Spontaneous breathing has been shown to induce both positive and negative effects on the function and on injury of lungs and diaphragm during critical illness; thus, monitoring of the breathing effort generated by the patient might be valuable for a better understanding of the mechanisms of disease and to set properly ventilation. The purpose of this review is to summarize the recent findings on the different techniques available to measure the patient's breathing effort, mainly during spontaneous assisted ventilation. RECENT FINDINGS Although esophageal pressure measurement remains the solid reference technique to quantitate the breathing effort, other tools have been developed and tested. These include the diaphragmatic electromyogram, whose voltage is linearly related to the pressure generated by the diaphragm, ultrasound, which relies on the measurement of diaphragmatic displacement or thickening, and other approaches, which derive breathing effort solely from the airway flow and pressure tracings. SUMMARY The development of measurement techniques and their introduction in clinical practice will allow us to understand the role of spontaneous breathing effort in the pathophysiology of lung injury and weaning failure, and how to adjust the breathing workload in an individual patient.
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18
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Abstract
Neurally adjusted ventilatory assist (NAVA) uses the electrical activity of the diaphragm (Edi) as a neural trigger to synchronize mechanical ventilatory breaths with the patient's neural respiratory drive. Using this signal enables the ventilator to proportionally support the patient's instantaneous drive on a breath-by-breath basis. Synchrony can be achieved even in the presence of significant air leaks, which make this an attractive choice for invasive and non-invasive ventilation of the neonate. This paper describes the Edi signal, neuroventilatory coupling, and patient-ventilator synchrony including the functional concept of NAVA. Safety features, NAVA terminology, and clinical application of NAVA to unload respiratory musculature are presented. The use of the Edi signal as a respiratory vital sign for conventional ventilation is discussed. The results of animal and adult studies are briefly summarized and detailed descriptions of all NAVA-related research in pediatric and neonatal patients are provided. Further studies are needed to determine whether NAVA will have significant impact on the overall outcomes of neonates.
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19
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Mirabella L, Grasselli G, Haitsma JJ, Zhang H, Slutsky AS, Sinderby C, Beck J. Lung protection during non-invasive synchronized assist versus volume control in rabbits. Crit Care 2014; 18:R22. [PMID: 24456613 PMCID: PMC4057206 DOI: 10.1186/cc13706] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 01/14/2014] [Indexed: 11/10/2022] Open
Abstract
Introduction Experimental work provides insight into potential lung protective strategies. The objective of this study was to evaluate markers of ventilator-induced lung injury after two different ventilation approaches: (1) a “conventional” lung-protective strategy (volume control (VC) with low tidal volume, positive end-expiratory pressure (PEEP) and paralysis), (2) a physiological approach with spontaneous breathing, permitting synchrony, variability and a liberated airway. For this, we used non-invasive Neurally Adjusted Ventilatory Assist (NIV-NAVA), with the hypothesis that liberation of upper airways and the ventilator’s integration with lung protective reflexes would be equally lung protective. Methods In this controlled and randomized in vivo laboratory study, 25 adult White New Zealand rabbits were studied, including five non-ventilated control animals. The twenty animals with aspiration-induced lung injury were randomized to ventilation with either VC (6 mL/kg, PEEP 5 cm H2O, and paralysis) or NIV-NAVA for six hours (PEEP = zero because of leaks). Markers of lung function, lung injury, vital signs and ventilator parameters were assessed. Results At the end of six hours of ventilation (n = 20), there were no significant differences between VC and NIV-NAVA for vital signs, PaO2/FiO2 ratio, lung wet-to-dry ratio and broncho-alveolar Interleukin 8 (Il-8). Plasma IL-8 was higher in VC (P <0.05). Lung injury score was lower for NIV-NAVA (P = 0.03). Dynamic lung compliance recovered after six hours in NIV-NAVA but not in VC (P <0.05). During VC, peak pressures increased from 9.2 ± 2.4 cm H2O (hour 1) to 12.3 ± 12.3 cm H2O (hour 6) (P <0.05). During NIV-NAVA, the tracheal end-expiratory pressure was similar to the end-expiratory pressure during VC. Two animals regurgitated during NIV-NAVA, without clinical consequences, and survived the protocol. Conclusions In experimental acute lung injury, NIV-NAVA is as lung-protective as VC 6 ml/kg with PEEP. Electronic supplementary material The online version of this article (doi:10.1186/cc13706) contains supplementary material, which is available to authorized users.
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Year in review in Intensive Care Medicine 2012: I. Neurology and neurointensive care, epidemiology and nephrology, biomarkers and inflammation, nutrition, experimentals. Intensive Care Med 2012; 39:232-46. [PMID: 23248038 PMCID: PMC3569582 DOI: 10.1007/s00134-012-2774-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 11/29/2012] [Indexed: 01/06/2023]
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