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Quiros KAM, Nelson TM, Ulu A, Dominguez EC, Biddle TA, Lo DD, Nordgren TM, Eskandari M. A Comparative Study of Ex-Vivo Murine Pulmonary Mechanics Under Positive- and Negative-Pressure Ventilation. Ann Biomed Eng 2024; 52:342-354. [PMID: 37906375 PMCID: PMC10808462 DOI: 10.1007/s10439-023-03380-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 10/03/2023] [Indexed: 11/02/2023]
Abstract
Increased ventilator use during the COVID-19 pandemic resurrected persistent questions regarding mechanical ventilation including the difference between physiological and artificial breathing induced by ventilators (i.e., positive- versus negative-pressure ventilation, PPV vs NPV). To address this controversy, we compare murine specimens subjected to PPV and NPV in ex vivo quasi-static loading and quantify pulmonary mechanics via measures of quasi-static and dynamic compliances, transpulmonary pressure, and energetics when varying inflation frequency and volume. Each investigated mechanical parameter yields instance(s) of significant variability between ventilation modes. Most notably, inflation compliance, percent relaxation, and peak pressure are found to be consistently dependent on the ventilation mode. Maximum inflation volume and frequency note varied dependencies contingent on the ventilation mode. Contradictory to limited previous clinical investigations of oxygenation and end-inspiratory measures, the mechanics-focused comprehensive findings presented here indicate lung properties are dependent on loading mode, and importantly, these dependencies differ between smaller versus larger mammalian species despite identical custom-designed PPV/NPV ventilator usage. Results indicate that past contradictory findings regarding ventilation mode comparisons in the field may be linked to the chosen animal model. Understanding the differing fundamental mechanics between PPV and NPV may provide insights for improving ventilation strategies and design to prevent associated lung injuries.
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Affiliation(s)
- K A M Quiros
- Department of Mechanical Engineering, University of California Riverside, 900 University Ave., Riverside, CA, 92506, USA
| | - T M Nelson
- Department of Mechanical Engineering, University of California Riverside, 900 University Ave., Riverside, CA, 92506, USA
| | - A Ulu
- Division of Biomedical Sciences, Riverside School of Medicine, University of California, Riverside, CA, USA
| | - E C Dominguez
- Division of Biomedical Sciences, Riverside School of Medicine, University of California, Riverside, CA, USA
- Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA
| | - T A Biddle
- Division of Biomedical Sciences, Riverside School of Medicine, University of California, Riverside, CA, USA
- Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA
- School of Medicine, BREATHE Center, University of California, Riverside, CA, USA
| | - D D Lo
- Division of Biomedical Sciences, Riverside School of Medicine, University of California, Riverside, CA, USA
- School of Medicine, BREATHE Center, University of California, Riverside, CA, USA
- Center for Health Disparities Research, University of California, Riverside, CA, USA
| | - T M Nordgren
- Division of Biomedical Sciences, Riverside School of Medicine, University of California, Riverside, CA, USA
- Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA
- School of Medicine, BREATHE Center, University of California, Riverside, CA, USA
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - M Eskandari
- Department of Mechanical Engineering, University of California Riverside, 900 University Ave., Riverside, CA, 92506, USA.
- School of Medicine, BREATHE Center, University of California, Riverside, CA, USA.
- Department of Bioengineering, University of California, Riverside, CA, USA.
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Etienne H, Morris IS, Hermans G, Heunks L, Goligher EC, Jaber S, Morelot-Panzini C, Assouad J, Gonzalez-Bermejo J, Papazian L, Similowski T, Demoule A, Dres M. Diaphragm Neurostimulation Assisted Ventilation in Critically Ill Patients. Am J Respir Crit Care Med 2023; 207:1275-1282. [PMID: 36917765 PMCID: PMC10595441 DOI: 10.1164/rccm.202212-2252cp] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/14/2023] [Indexed: 03/15/2023] Open
Abstract
Diaphragm neurostimulation consists of placing electrodes directly on or in proximity to the phrenic nerve(s) to elicit diaphragmatic contractions. Since its initial description in the 18th century, indications have shifted from cardiopulmonary resuscitation to long-term ventilatory support. Recently, the technical development of devices for temporary diaphragm neurostimulation has opened up the possibility of a new era for the management of mechanically ventilated patients. Combining positive pressure ventilation with diaphragm neurostimulation offers a potentially promising new approach to the delivery of mechanical ventilation which may benefit multiple organ systems. Maintaining diaphragm contractions during ventilation may attenuate diaphragm atrophy and accelerate weaning from mechanical ventilation. Preventing atelectasis and preserving lung volume can reduce lung stress and strain and improve homogeneity of ventilation, potentially mitigating ventilator-induced lung injury. Furthermore, restoring the thoracoabdominal pressure gradient generated by diaphragm contractions may attenuate the drop in cardiac output induced by positive pressure ventilation. Experimental evidence suggests diaphragm neurostimulation may prevent neuroinflammation associated with mechanical ventilation. This review describes the historical development and evolving approaches to diaphragm neurostimulation during mechanical ventilation and surveys the potential mechanisms of benefit. The review proposes a research agenda and offers perspectives for the future of diaphragm neurostimulation assisted mechanical ventilation for critically ill patients.
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Affiliation(s)
- Harry Etienne
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Department of Thoracic Surgery, Tenon University Hospital, Paris, France
| | - Idunn S. Morris
- Interdepartmental Division of Critical Care Medicine and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Division of Respirology, Department of Medicine, University Health Network, Toronto, Ontario, Canada
- Department of Intensive Care Medicine, Nepean Hospital, Kingswood, New South Wales, Australia
| | - Greet Hermans
- Medical Intensive Care Unit, Department of General Internal Medicine, University Hospital Leuven, Leuven, Belgium
- Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Leo Heunks
- Department of Intensive Care, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Ewan C. Goligher
- Interdepartmental Division of Critical Care Medicine and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Division of Respirology, Department of Medicine, University Health Network, Toronto, Ontario, Canada
- Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Samir Jaber
- Intensive Care and Anesthesiology Department, Saint Eloi Hospital, Montpellier, France
| | - Capucine Morelot-Panzini
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Service de Pneumologie
| | - Jalal Assouad
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Department of Thoracic Surgery, Tenon University Hospital, Paris, France
| | - Jésus Gonzalez-Bermejo
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Service de Soins de Suite Réadaptation
| | - Laurent Papazian
- Service de Médecine Intensive Reanimation, Centre Hospitalier de Bastia, Bastia, France
| | - Thomas Similowski
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Département R3S, and
| | - Alexandre Demoule
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Service de Médecine Intensive – Réanimation, Hopital Pitie Salpetriere, APHP, Sorbonne Universite, Paris, France; and
| | - Martin Dres
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
- Service de Médecine Intensive – Réanimation, Hopital Pitie Salpetriere, APHP, Sorbonne Universite, Paris, France; and
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Sattari S, Mariano CA, Kuschner WG, Taheri H, Bates JHT, Eskandari M. Positive- and Negative-Pressure Ventilation Characterized by Local and Global Pulmonary Mechanics. Am J Respir Crit Care Med 2023; 207:577-586. [PMID: 36194677 PMCID: PMC10870900 DOI: 10.1164/rccm.202111-2480oc] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 10/04/2022] [Indexed: 11/16/2022] Open
Abstract
Rationale: There is continued debate regarding the equivalency of positive-pressure ventilation (PPV) and negative-pressure ventilation (NPV). Resolving this question is important because of the different practical ramifications of the two paradigms. Objectives: We sought to investigate the parallel between PPV and NPV and determine whether or not these two paradigms cause identical ventilation profiles by analyzing the local strain mechanics when the global tidal volume (Vt) and inflation pressure was matched. Methods: A custom-designed electromechanical apparatus was used to impose equal global loads and displacements on the same ex vivo healthy porcine lung using PPV and NPV. High-speed high-resolution cameras recorded local lung surface deformations and strains in real time, and differences between PPV and NPV global energetics, viscoelasticity, as well as local tissue distortion were assessed. Measurements and Main Results: During initial inflation, NPV exhibited significantly more bulk pressure-volume compliance than PPV, suggestive of earlier lung recruitment. NPV settings also showed reduced relaxation, hysteresis, and energy loss compared with PPV. Local strain trends were also decreased in NPV, with reduced tissue distortion trends compared with PPV, as revealed through analysis of tissue anisotropy. Conclusions: Apparently, contradictory previous studies are not mutually exclusive. Equivalent changes in transpulmonary pressures in PPV and NPV lead to the same changes in lung volume and pressures, yet local tissue strains differ between PPV and NPV. Although limited to healthy specimens and ex vivo experiments in the absence of a chest cavity, these results may explain previous reports of better oxygenation and less lung injury in NPV.
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Affiliation(s)
| | | | - Ware G. Kuschner
- Medical Service, Veterans Affairs Palo Alto Health Care System, Division of Pulmonary, Allergy & Critical Care Medicine, Stanford University, Stanford, California; and
| | | | - Jason H. T. Bates
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont
| | - Mona Eskandari
- Department of Mechanical Engineering
- BREATHE Center, School of Medicine, and
- Department of Bioengineering, University of California Riverside, Riverside, California
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van Rijn CM, van Egmond J, Howard D, Coulthard MG, Perella P, Roberts JHM, McKeown D. Negative pressure ventilation protects the brain. Crit Care 2022; 26:334. [PMID: 36316698 PMCID: PMC9624026 DOI: 10.1186/s13054-022-04150-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 08/25/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- C. M. van Rijn
- grid.5590.90000000122931605Donders Institute for Brain, Cognition and Behaviour, Donders Centre for Cognition, Radboud University, Thomas van Aquinostraat 4, 6525 GD Nijmegen, The Netherlands
| | - J. van Egmond
- grid.5590.90000000122931605Donders Institute for Brain, Cognition and Behaviour, Donders Centre for Cognition, Radboud University, Thomas van Aquinostraat 4, 6525 GD Nijmegen, The Netherlands
| | - D. Howard
- grid.413820.c0000 0001 2191 5195Charing Cross Hospital, London, UK
| | - M. G. Coulthard
- grid.1006.70000 0001 0462 7212Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - P. Perella
- grid.52996.310000 0000 8937 2257The Royal National Ear, Nose and Throat and Eastman Dental Hospitals, UCLH, London, UK
| | - J. H. M. Roberts
- grid.52996.310000 0000 8937 2257The Royal National Ear, Nose and Throat and Eastman Dental Hospitals, UCLH, London, UK
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Dong S, Wang L, Chitano P, Coxson HO, Vasilescu DM, Paré PD, Seow CY. Lung resistance and elastance are different in ex vivo sheep lungs ventilated by positive and negative pressures. Am J Physiol Lung Cell Mol Physiol 2022; 322:L673-L682. [PMID: 35272489 DOI: 10.1152/ajplung.00464.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung resistance (RL) and elastance (EL) can be measured during positive or negative pressure ventilation. Whether the different modes of ventilation produce different RL and EL is still being debated. Although negative pressure ventilation (NPV) is more physiological, positive pressure ventilation (PPV) is more commonly used for treating respiratory failure. In the present study we measured lung volume, airway diameter and airway volume, as well as RL and EL with PPV and NPV in explanted sheep lungs. We found that lung volume under a static pressure, either positive or negative, was not different. However, RL and EL were significantly higher in NPV at high inflation pressures. Interestingly, diameters of smaller airways (diameters < 3.5 mm) and total airway volume were significantly greater at high negative inflation pressures compared with those at high positive inflation pressures. This suggests that NPV is more effective in distending the peripheral airways, likely due to the fact that negative pressure is applied through the pleural membrane and reaches the central airways via the peripheral airways, whereas positive pressure is applied in the opposite direction. More distension of lung periphery could explain why RL is higher in NPV (vs. PPV), because the peripheral parenchyma is a major source of tissue resistance, which is a part of the RL that increases with pressure. This explanation is consistent with the finding that during high frequency ventilation (>1 Hz, where RL reflects airway resistance more than tissue resistance), the difference in RL between NPV and PPV disappeared.
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Affiliation(s)
- Shoujin Dong
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada.,Respiratory Department, Chengdu First People's Hospital, Chengdu, China
| | - Lu Wang
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada
| | - Pasquale Chitano
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada
| | - Harvey O Coxson
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada
| | | | - Peter D Paré
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Chun Y Seow
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
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Chandrasekaran K, Monikandan Shaji A. “The role of a negative pressure ventilator coupled with oxygen helmet against COVID-19: a review”. RESEARCH ON BIOMEDICAL ENGINEERING 2022. [PMCID: PMC8060160 DOI: 10.1007/s42600-021-00149-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Background The coronavirus (SARS-COV-2) pandemic has provoked the global healthcare industry by potentially affecting more than 20 14 million people across the globe, causing lasting damage to the lungs, notably pneumonia, ARDS (acute respiratory distress 15 syndrome), and sepsis with the rapid spread of infection. To aid the functioning of the lungs and to maintain the blood oxygen 16 saturation (SpO2) in coronavirus patients, ventilator assistance is required. Materials and methods The main purpose of this article is to outline the need 17 for the introduction of a non-invasive negative pressure ventilator (NINPV) as a promising alternative to positive pressure 18 ventilator (PPV) by elucidating the cons of non-invasive ventilators in clinical conditions like ARDS. Another motive is to 19 profoundly diminish the rate of infection spread by the employment of oxygen helmets, instead of endotracheal intubation in 20 invasive positive pressure ventilator (IPPV) or non-invasive positive pressure ventilator (NIPPV) like face masks and high-flow 21 nasal cannula (HFNC). Result and conclusion The integration of oxygen helmet with NPV would result in a number of notable facets including the 22 degree of comfort delivered to patients who are exposed to various ventilator-induced lung injuries (VILI) in the forms of 23 atelectasis, barotrauma, etc. Likewise, preventing the aerosol-generating procedures (AGP) diminishes the rate of nosocomial 24 infections and providing a better environment to both the patients and the healthcare professionals.
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Affiliation(s)
| | - Aadharsha Monikandan Shaji
- Department of Biomedical Engineering, Sri Shakthi Institute of Engineering and Technology, Coimbatore, Tamil Nadu India
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Bobba CM, Nelson K, Dumond C, Eren E, Black SM, Englert JA, Ghadiali SN, Whitson BA. A Novel Negative Pressure-Flow Waveform to Ventilate Lungs for Normothermic Ex Vivo Lung Perfusion. ASAIO J 2021; 67:96-103. [PMID: 32404613 PMCID: PMC9218878 DOI: 10.1097/mat.0000000000001168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Ex vivo lung perfusion (EVLP) is increasingly used to treat and assess lungs before transplant. Minimizing ventilator induced lung injury (VILI) during EVLP is an important clinical need, and negative pressure ventilation (NPV) may reduce VILI compared with conventional positive pressure ventilation (PPV). However, it is not clear if NPV is intrinsically lung protective or if differences in respiratory pressure-flow waveforms are responsible for reduced VILI during NPV. In this study, we quantified lung injury using novel pressure-flow waveforms during normothermic EVLP. Rat lungs were ventilated-perfused ex vivo for 2 hours using tidal volume, positive end-expiratory pressure (PEEP), and respiratory rate matched PPV or NPV protocols. Airway pressures and flow rates were measured in real time and lungs were assessed for changes in compliance, pulmonary vascular resistance, oxygenation, edema, and cytokine secretion. Negative pressure ventilation lungs demonstrated reduced proinflammatory cytokine secretion, reduced weight gain, and reduced pulmonary vascular resistance (p < 0.05). Compliance was higher in NPV lungs (p < 0.05), and there was no difference in oxygenation between the two groups. Respiratory pressure-flow waveforms during NPV and PPV were significantly different (p < 0.05), especially during the inspiratory phase, where the NPV group exhibited rapid time-dependent changes in pressure and airflow whereas the PPV group exhibited slower changes in airflow/pressures. Lungs ventilated with PPV also had a greater transpulmonary pressure (p < 0.05). Greater improvement in lung function during NPV EVLP may be caused by favorable airflow patterns and/or pressure dynamics, which may better mimic human respiratory patterns.
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Affiliation(s)
- Christopher M Bobba
- From the Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Kevin Nelson
- From the Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Curtis Dumond
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio; and
- Department of Surgery, Collaboration for Organ Perfusion, Protection, Engineering and Regeneration (COPPER) Laboratory, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Emre Eren
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio; and
- Department of Surgery, Collaboration for Organ Perfusion, Protection, Engineering and Regeneration (COPPER) Laboratory, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Sylvester M Black
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio; and
- Department of Surgery, Collaboration for Organ Perfusion, Protection, Engineering and Regeneration (COPPER) Laboratory, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Joshua A Englert
- From the Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Samir N Ghadiali
- From the Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Bryan A Whitson
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio; and
- Department of Surgery, Collaboration for Organ Perfusion, Protection, Engineering and Regeneration (COPPER) Laboratory, The Ohio State University Wexner Medical Center, Columbus, Ohio
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9
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New non invasive ventilator strategy applied to COPD patients in acute ventilator failure. Pulm Pharmacol Ther 2017; 46:64-68. [PMID: 28823948 DOI: 10.1016/j.pupt.2017.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/26/2017] [Accepted: 08/15/2017] [Indexed: 11/21/2022]
Abstract
INTRODUCTION There is no evidence in the literature regarding the combined use of positive ventilation with negative ventilation. A recent study reported that the two techniques can be combined in patients with ARDS, who undergo ventilatory support for severe acute respiratory failure (ARF). There is experience of non-invasive ventilation in patients with chronic respiratory diseases and ARF. The aim of this study was to test the efficacy of a non-invasive ventilatory strategy based on the combined use of negative (N) and positive ventilation (P) in bi-level mode (PN). METHODS We enrolled 8 patients with severe COPD exacerbations and exacerbated chronic respiratory failure admitted in a monitored setting of an intermediate-intensive respiratory Unit. RESULTS Patients underwent combined positive/negative ventilation and at different times, in place of the two singular ventilation modes (P and N). After each cycle, in the combined P/N ventilatory mode, gas exchanges were significantly increased compared to the two singular P/N mode: pH (7.42 vs 7.40 and 7.40); PCO2 (85.01 vs 72.05 and 66.81 mmHg); FiO2/PO2 (488.75 vs 352.62 and 327.87). All patients well tolerated the application of the double ventilation mode. CONCLUSIONS In conclusion, the use of dual mode ventilation appears well tolerated and superior to the individual modes in patients with COPD exacerbations and ARF.
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Diaphragm Activation in Ventilated Patients Using a Novel Transvenous Phrenic Nerve Pacing Catheter. Crit Care Med 2017; 45:e691-e694. [PMID: 28441238 DOI: 10.1097/ccm.0000000000002366] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Over 30% of critically ill patients on positive-pressure mechanical ventilation have difficulty weaning from the ventilator, many of whom acquire ventilator-induced diaphragm dysfunction. Temporary transvenous phrenic nerve pacing using a novel electrode-bearing catheter may provide a means to prevent diaphragm atrophy, to strengthen an atrophied diaphragm, and mitigate the harms of mechanical ventilation. We tested the initial safety, feasibility, and impact on ventilation of this novel approach. DESIGN First-in-Humans case series. SETTING Angiogram suite. PATIENTS Twenty-four sedated, mechanically ventilated patients immediately prior to an elective atrial septal defect repair procedure. INTERVENTIONS A 9.5-Fr central venous catheter with 19 embedded electrodes was placed via Seldinger technique into the left subclavian vein and superior vena cava and evaluated for up to 90 minutes. The electrode combinations determined to provide best transvenous stimulation of the right and left phrenic nerves were activated in synchrony with mechanically ventilated breaths. MEASUREMENTS AND MAIN RESULTS One patient could not be tested for reasons unrelated to the device. In the 23 patients who underwent the full protocol, transvenous stimulation activated the diaphragm in 22 of 23 (96%) left phrenic capture attempts and 20 of 23 (87%) right phrenic capture attempts. In one subject, a congenital left-sided superior vena cava precluded right-sided capture. Significant reductions in ventilator pressure-time-product were achieved during stimulation assisted breaths in all 22 paced subjects (range, 9.9-48.6%; p < 0.001). There were no adverse events either immediately or at 2-week follow-up. CONCLUSIONS In this First-in-Human series, diaphragm pacing with a temporary catheter was safe and effectively contributed to ventilation in conjunction with a mechanical ventilator.
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Combined Negative- and Positive-Pressure Ventilation for the Treatment of ARDS. Case Rep Crit Care 2015; 2015:714902. [PMID: 26290758 PMCID: PMC4531190 DOI: 10.1155/2015/714902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/28/2015] [Indexed: 11/18/2022] Open
Abstract
Objective. Tracheal intubation and positive-pressure ventilation as the current standard of care for the adult respiratory distress syndrome (ARDS) seem to have reached their limit in terms of a further relevant reduction of the still very high mortality. Case Presentation. A 75-year-old male patient developed ARDS after abscess drainage with deteriorating oxygenation, despite positive end-expiratory pressure (PEEP) values above 15 cm H2O. We applied external negative-pressure ventilation with a chamber respirator using -33 cm H2O at inspiration and -15 cm H2O at expiration, combined with conventional pressure support using a PEEP of about 8 cm H2O and a pressure support of 4-12 cm H2O. Alveolar infiltrates disappeared rapidly and PaO2/FiO2 values surpassed 300 mmHg after the first application and 500 mmHg after the second. Negative-pressure ventilation was used for 6-18 hours/day over five days. Now, 13 years later, the patient is still alive and has a good quality of life. Conclusion. Using this or similar concepts, not only in intubated patients but also as a noninvasive approach in patients with ARDS, offers new options that may genuinely differ from the present therapeutic approaches and may, therefore, have the potential to decrease the present high mortality from ARDS.
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12
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Laight NS, Levin AI. Transcardiopulmonary Thermodilution-Calibrated Arterial Waveform Analysis: A Primer for Anesthesiologists and Intensivists. J Cardiothorac Vasc Anesth 2015; 29:1051-64. [PMID: 26279223 DOI: 10.1053/j.jvca.2015.03.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 02/07/2023]
Affiliation(s)
- Nicola S Laight
- Department of Anesthesiology and Critical Care, University of Stellenbosch, Tygerberg Hospital, Cape Town, South Africa
| | - Andrew I Levin
- Department of Anesthesiology and Critical Care, University of Stellenbosch, Tygerberg Hospital, Cape Town, South Africa.
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13
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Braun NMT. Negative Pressure Noninvasive Ventilation (NPNIV): History, Rationale, and Application. NOCTURNAL NON-INVASIVE VENTILATION 2015. [PMCID: PMC7122449 DOI: 10.1007/978-1-4899-7624-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Man has recognized the vital role of breathing since antiquity, beginning with archeological findings depicting inhalation therapy using herbs, oils, and other substances since 6000 BC. Man has taken the automaticity of breathing for granted, expecting its adequacy for all activities whether awake or asleep. Dickinson W. Richards, MD, Nobel Laureate, said in 1962: “Breathing is that essential physiologic function that is straddled between the conscious & the unconscious and subject to both.” The understanding of the components of this critical physiologic function that starts at birth, and must be continuous and widely adaptable to support all levels of physical, metabolic, and functional needs, has evolved slowly over the millennia by many brilliant scientists from a combination of keen observation, imagination, daring experimentation, trial and error, and necessity, while overcoming dogma, religious inhibitions, and politics. It is this gradual chronologic process, still evolving, which guides what we do for patients today.
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Goligher EC, Fan E, Slutsky AS. Year in review 2012: Critical Care--Respirology. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:249. [PMID: 24267541 PMCID: PMC4056602 DOI: 10.1186/cc13129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Acute respiratory failure is a dominant feature of critical illness. In this review, we discuss 17 studies published last year in Critical Care. The discussion focuses on articles on several topics: respiratory monitoring, acute respiratory distress syndrome, noninvasive ventilation, airway management, secretion management and weaning.
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Negative pressure ventilation and positive pressure ventilation promote comparable levels of ventilator-induced diaphragmatic dysfunction in rats. Anesthesiology 2013; 119:652-62. [PMID: 23838714 DOI: 10.1097/aln.0b013e31829b3692] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Mechanical ventilation is a life-saving intervention for patients with respiratory failure. Unfortunately, a major complication associated with prolonged mechanical ventilation is ventilator-induced diaphragmatic atrophy and contractile dysfunction, termed ventilator-induced diaphragmatic dysfunction (VIDD). Emerging evidence suggests that positive pressure ventilation (PPV) promotes lung damage (ventilator-induced lung injury [VILI]), resulting in the release of signaling molecules that foster atrophic signaling in the diaphragm and the resultant VIDD. Although a recent report suggests that negative pressure ventilation (NPV) results in less VILI than PPV, it is unknown whether NPV can protect against VIDD. Therefore, the authors tested the hypothesis that compared with PPV, NPV will result in a lower level of VIDD. METHODS Adult rats were randomly assigned to one of three experimental groups (n = 8 each): (1) acutely anesthetized control (CON), (2) 12 h of PPV, and (3) 12 h of NPV. Dependent measures included indices of VILI, diaphragmatic muscle fiber cross-sectional area, diaphragm contractile properties, and the activity of key proteases in the diaphragm. RESULTS Our results reveal that no differences existed in the degree of VILI between PPV and NPV animals as evidenced by VILI histological scores (CON = 0.082 ± 0.001; PPV = 0.22 ± 0.04; NPV = 0.25 ± 0.02; mean ± SEM). Both PPV and NPV resulted in VIDD. Importantly, no differences existed between PPV and NPV animals in diaphragmatic fiber cross-sectional area, contractile properties, and the activation of proteases. CONCLUSION These results demonstrate that NPV and PPV result in similar levels of VILI and that NPV and PPV promote comparable levels of VIDD in rats.
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Pulmonary Shunt Is Independent of Decrease in Cardiac Output during Unsupported Spontaneous Breathing in the Pig. Anesthesiology 2013; 118:914-23. [DOI: 10.1097/aln.0b013e318283c81f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abstract
Background:
During mechanical ventilation (MV), pulmonary shunt is cardiac output (CO) dependent; however, whether this relationship is valid during unsupported spontaneous breathing (SB) is unknown. The CO dependency of the calculated venous admixture was investigated, with both minor and major shunt, during unsupported SB, MV, and SB with continuous positive airway pressure (CPAP).
Methods:
In seven anesthetized supine piglets breathing 100% oxygen, unsupported SB, MV (with tidal volume and respiratory rate corresponding to SB), and 8 cm H2O CPAP (airway pressure corresponding to MV) were applied at random. Venous return and CO were reduced by partial balloon occlusion of the inferior vena cava. Measurements were repeated with the left main bronchus blocked, creating a nonrecruitable pulmonary shunt.
Results:
CO decreased from 4.2 l/min (95% CI, 3.9–4.5) to 2.5 l/min (95% CI, 2.2–2.7) with partially occluded venous return. Irrespective of whether shunt was minor or major, during unsupported SB, venous admixture was independent of CO (slope: minor shunt, 0.5; major shunt, 1.1%·min−1·l−1) and mixed venous oxygen tension. During both MV and CPAP, venous admixture was dependent on CO (slope MV: minor shunt, 1.9; major shunt, 3.5; CPAP: minor shunt, 1.3; major shunt, 2.9%·min−1·l−1) and mixed-venous oxygen tension (coefficient of determination 0.61–0.86 for all regressions).
Conclusions:
In contrast to MV and CPAP, venous admixture was independent of CO during unsupported SB, and was unaffected by mixed-venous oxygen tension, casting doubt on the role of hypoxic pulmonary vasoconstriction in pulmonary blood flow redistribution during unsupported SB.
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