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Lutz MR, Charlamb J, Kenna JR, Smith A, Glatt SJ, Araos JD, Andrews PL, Habashi NM, Nieman GF, Ghosh AJ. Inconsistent Methods Used to Set Airway Pressure Release Ventilation in Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Regression Analysis. J Clin Med 2024; 13:2690. [PMID: 38731219 DOI: 10.3390/jcm13092690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/15/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024] Open
Abstract
Airway pressure release ventilation (APRV) is a protective mechanical ventilation mode for patients with acute respiratory distress syndrome (ARDS) that theoretically may reduce ventilator-induced lung injury (VILI) and ARDS-related mortality. However, there is no standard method to set and adjust the APRV mode shown to be optimal. Therefore, we performed a meta-regression analysis to evaluate how the four individual APRV settings impacted the outcome in these patients. Methods: Studies investigating the use of the APRV mode for ARDS patients were searched from electronic databases. We tested individual settings, including (1) high airway pressure (PHigh); (2) low airway pressure (PLow); (3) time at high airway pressure (THigh); and (4) time at low pressure (TLow) for association with PaO2/FiO2 ratio and ICU length of stay. Results: There was no significant difference in PaO2/FiO2 ratio between the groups in any of the four settings (PHigh difference -12.0 [95% CI -100.4, 86.4]; PLow difference 54.3 [95% CI -52.6, 161.1]; TLow difference -27.19 [95% CI -127.0, 72.6]; THigh difference -51.4 [95% CI -170.3, 67.5]). There was high heterogeneity across all parameters (PhHgh I2 = 99.46%, PLow I2 = 99.16%, TLow I2 = 99.31%, THigh I2 = 99.29%). Conclusions: None of the four individual APRV settings independently were associated with differences in outcome. A holistic approach, analyzing all settings in combination, may improve APRV efficacy since it is known that small differences in ventilator settings can significantly alter mortality. Future clinical trials should set and adjust APRV based on the best current scientific evidence available.
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Affiliation(s)
- Mark R Lutz
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jacob Charlamb
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Joshua R Kenna
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Abigail Smith
- Health Sciences Library, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Stephen J Glatt
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY 13210, USA
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
- Department of Public Health and Preventive Medicine, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Joaquin D Araos
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Penny L Andrews
- Department of Critical Care, R Adams Cowley Shock Trauma Center, Baltimore, MD 21201, USA
| | - Nader M Habashi
- Department of Critical Care, R Adams Cowley Shock Trauma Center, Baltimore, MD 21201, USA
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Auyon J Ghosh
- Division of Pulmonary, Critical Care, and Sleep Medicine, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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Bates JHT, Kaczka DW, Kollisch-Singule M, Nieman GF, Gaver DP. Mechanical Power and Ventilator-induced Lung Injury: What Does Physics Have to Say? Am J Respir Crit Care Med 2024; 209:787-788. [PMID: 37729623 PMCID: PMC10995572 DOI: 10.1164/rccm.202307-1292vp] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/20/2023] [Indexed: 09/22/2023] Open
Affiliation(s)
| | - David W. Kaczka
- Department of Anesthesia, Department of Radiology, and Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | | | - Gary F. Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York; and
| | - Donald P. Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana
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Ramcharran H, Wetmore G, Cooper S, Herrmann J, Cruz AF, Kaczka DW, Satalin J, Blair S, Andrews PL, Habashi NM, Nieman GF, Kollisch-Singule M. Effects of Lung Injury and Abdominal Insufflation on Respiratory Mechanics and Lung Volume During Time-Controlled Adaptive Ventilation. Respir Care 2024:respcare.11745. [PMID: 38408775 DOI: 10.4187/respcare.11745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 02/17/2024] [Indexed: 02/28/2024]
Abstract
BACKGROUND Lung volume measurements are important for monitoring functional aeration and recruitment, and may help guide adjustments in ventilator settings. The expiratory phase of APRV may provide physiologic information about lung volume based on the expiratory flow-time slope, angle, and time to approach a no-flow state (TExp). We hypothesized that expiratory flow rate would correlate with estimated lung volume (ELV), as measured using a modified nitrogen washout/washin technique in a large animal lung injury model. METHODS Eight pigs (35.2±1.0kg) were mechanically ventilated using an Engström Carescape R860 on the APRV mode. All settings were held constant except the expiratory duration (TLow), which was adjusted based on the expiratory flow curve. Abdominal pressure was increased to 15mmHg in normal and Tween-injured lungs to replicate a combination of pulmonary and extrapulmonary lung injury. ELV was estimated using the Carescape FRC InView Tool. The expiratory flow-time slope and TExp were measured from the expiratory flow profile. RESULTS Lung elastance increased with Tween-induced lung injury from 29.3±7.3cmH2O/L to 39.9±15.1cmH2O/L and chest wall elastance increased with increasing intra-abdominal pressures from 15.3±4.1cmH2O/L to 25.7±10.0cmH2O/L in the normal lung and 15.8±6.0cmH2O/L to 33.0±6.2cmH2O/L in the Tween-injured lung (p=0.39). ELV decreased from 1.90±0.83L in the Tween-Injured lung to 0.67±0.1L by increasing intra-abdominal pressures to 15mmHg. This had a significant correlation with a TExp decrease from 2.3±0.8s to 1.0±0.1s in the Tween-injured group with increasing insufflation pressures (ρ = 0.95) and with the expiratory flow-time slope, which increased from 0.29±0.06L/s2 to 0.63±0.05L/s2 (ρ = 0.78). CONCLUSIONS Changes in ELV over time, and the TExp and flow-time slope, can be used to demonstrate evolving lung injury during APRV. Using the slope to infer changes in functional lung volume represents a unique, reproducible, real-time, bedside technique that does not interrupt ventilation and may be used for clinical interpretation.
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Affiliation(s)
- Harry Ramcharran
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Greg Wetmore
- Department of Surgery, University of Cincinnati, Cincinnati, OH
| | - Scott Cooper
- Department of Internal Medicine, Morehouse School of Medicine, Atlanta, GA
| | - Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA
| | - Andrea F Cruz
- Department of Anesthesia, University of Iowa, Iowa City, IA
| | - David W Kaczka
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA
- Department of Anesthesia, University of Iowa, Iowa City, IA
- Department of Radiology, University of Iowa, Iowa City, IA
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Sarah Blair
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - Penny L Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY
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Camporota L, Rose L, Andrews PL, Nieman GF, Habashi NM. Airway pressure release ventilation for lung protection in acute respiratory distress syndrome: an alternative way to recruit the lungs. Curr Opin Crit Care 2024; 30:76-84. [PMID: 38085878 DOI: 10.1097/mcc.0000000000001123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
PURPOSE OF REVIEW Airway pressure release ventilation (APRV) is a modality of ventilation in which high inspiratory continuous positive airway pressure (CPAP) alternates with brief releases. In this review, we will discuss the rationale for APRV as a lung protective strategy and then provide a practical introduction to initiating APRV using the time-controlled adaptive ventilation (TCAV) method. RECENT FINDINGS APRV using the TCAV method uses an extended inspiratory time and brief expiratory release to first stabilize and then gradually recruit collapsed lung (over hours/days), by progressively 'ratcheting' open a small volume of collapsed tissue with each breath. The brief expiratory release acts as a 'brake' preventing newly recruited units from re-collapsing, reversing the main drivers of ventilator-induced lung injury (VILI). The precise timing of each release is based on analysis of expiratory flow and is set to achieve termination of expiratory flow at 75% of the peak expiratory flow. Optimization of the release time reflects the changes in elastance and, therefore, is personalized (i.e. conforms to individual patient pathophysiology), and adaptive (i.e. responds to changes in elastance over time). SUMMARY APRV using the TCAV method is a paradigm shift in protective lung ventilation, which primarily aims to stabilize the lung and gradually reopen collapsed tissue to achieve lung homogeneity eliminating the main mechanistic drivers of VILI.
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Affiliation(s)
- Luigi Camporota
- Department of Critical Care, Guy's & St Thomas' NHS Foundation Trust
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences
| | - Louise Rose
- Department of Critical Care, Guy's & St Thomas' NHS Foundation Trust
- Florence Nightingale Faculty of Nursing, Midwifery, and Palliative Care, King's College London, London, UK
| | - Penny L Andrews
- Department of Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland
| | - Gary F Nieman
- Department of Surgery, Upstate Medical University, Syracuse, New York, USA
| | - Nader M Habashi
- Department of Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland
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Al-Khalisy H, Nieman GF, Kollisch-Singule M, Andrews P, Camporota L, Shiber J, Manougian T, Satalin J, Blair S, Ghosh A, Herrmann J, Kaczka DW, Gaver DP, Bates JHT, Habashi NM. Time-Controlled Adaptive Ventilation (TCAV): a personalized strategy for lung protection. Respir Res 2024; 25:37. [PMID: 38238778 PMCID: PMC10797864 DOI: 10.1186/s12931-023-02615-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/25/2023] [Indexed: 01/22/2024] Open
Abstract
Acute respiratory distress syndrome (ARDS) alters the dynamics of lung inflation during mechanical ventilation. Repetitive alveolar collapse and expansion (RACE) predisposes the lung to ventilator-induced lung injury (VILI). Two broad approaches are currently used to minimize VILI: (1) low tidal volume (LVT) with low-moderate positive end-expiratory pressure (PEEP); and (2) open lung approach (OLA). The LVT approach attempts to protect already open lung tissue from overdistension, while simultaneously resting collapsed tissue by excluding it from the cycle of mechanical ventilation. By contrast, the OLA attempts to reinflate potentially recruitable lung, usually over a period of seconds to minutes using higher PEEP used to prevent progressive loss of end-expiratory lung volume (EELV) and RACE. However, even with these protective strategies, clinical studies have shown that ARDS-related mortality remains unacceptably high with a scarcity of effective interventions over the last two decades. One of the main limitations these varied interventions demonstrate to benefit is the observed clinical and pathologic heterogeneity in ARDS. We have developed an alternative ventilation strategy known as the Time Controlled Adaptive Ventilation (TCAV) method of applying the Airway Pressure Release Ventilation (APRV) mode, which takes advantage of the heterogeneous time- and pressure-dependent collapse and reopening of lung units. The TCAV method is a closed-loop system where the expiratory duration personalizes VT and EELV. Personalization of TCAV is informed and tuned with changes in respiratory system compliance (CRS) measured by the slope of the expiratory flow curve during passive exhalation. Two potentially beneficial features of TCAV are: (i) the expiratory duration is personalized to a given patient's lung physiology, which promotes alveolar stabilization by halting the progressive collapse of alveoli, thereby minimizing the time for the reopened lung to collapse again in the next expiration, and (ii) an extended inspiratory phase at a fixed inflation pressure after alveolar stabilization gradually reopens a small amount of tissue with each breath. Subsequently, densely collapsed regions are slowly ratcheted open over a period of hours, or even days. Thus, TCAV has the potential to minimize VILI, reducing ARDS-related morbidity and mortality.
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Affiliation(s)
| | - Gary F Nieman
- SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA
| | | | - Penny Andrews
- R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD, USA
| | - Luigi Camporota
- Health Centre for Human and Applied Physiological Sciences, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Joseph Shiber
- University of Florida College of Medicine, Jacksonville, FL, USA
| | | | - Joshua Satalin
- SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Sarah Blair
- SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA
| | - Auyon Ghosh
- SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA
| | | | | | | | | | - Nader M Habashi
- R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD, USA
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Cruz AF, Herrmann J, Ramcharran H, Kollisch-Singule M, Tawhai MH, Bates JHT, Nieman GF, Kaczka DW. Sustained vs. Intratidal Recruitment in the Injured Lung During Airway Pressure Release Ventilation: A Computational Modeling Perspective. Mil Med 2023; 188:141-148. [PMID: 37948236 DOI: 10.1093/milmed/usad059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/03/2023] [Accepted: 02/14/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION During mechanical ventilation, cyclic recruitment and derecruitment (R/D) of alveoli result in focal points of heterogeneous stress throughout the lung. In the acutely injured lung, the rates at which alveoli can be recruited or derecruited may also be altered, requiring longer times at higher pressure levels to be recruited during inspiration, but shorter times at lower pressure levels to minimize collapse during exhalation. In this study, we used a computational model to simulate the effects of airway pressure release ventilation (APRV) on acinar recruitment, with varying inspiratory pressure levels and durations of exhalation. MATERIALS AND METHODS The computational model consisted of a ventilator pressure source, a distensible breathing circuit, an endotracheal tube, and a porcine lung consisting of recruited and derecruited zones, as well as a transitional zone capable of intratidal R/D. Lung injury was simulated by modifying each acinus with an inflation-dependent surface tension. APRV was simulated for an inhalation duration (Thigh) of 4.0 seconds, inspiratory pressures (Phigh) of 28 and 40 cmH2O, and exhalation durations (Tlow) ranging from 0.2 to 1.5 seconds. RESULTS Both sustained acinar recruitment and intratidal R/D within the subtree were consistently higher for Phigh of 40 cmH2O vs. 28 cmH2O, regardless of Tlow. Increasing Tlow was associated with decreasing sustained acinar recruitment, but increasing intratidal R/D, within the subtree. Increasing Tlow was associated with decreasing elastance of both the total respiratory system and transitional subtree of the model. CONCLUSIONS Our computational model demonstrates the confounding effects of cyclic R/D, sustained recruitment, and parenchymal strain stiffening on estimates of total lung elastance during APRV. Increasing inspiratory pressures leads to not only more sustained recruitment of unstable acini but also more intratidal R/D. Our model indicates that higher inspiratory pressures should be used in conjunction with shorter exhalation times, to avoid increasing intratidal R/D.
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Affiliation(s)
- Andrea F Cruz
- Department of Anesthesia, University of Iowa, Iowa City, IA 52242, USA
| | - Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Harry Ramcharran
- Department of Surgery, SUNY Upstate Medical Center, Syracuse, NY 13210, USA
| | | | - Merryn H Tawhai
- Department of Bioengineering, University of Auckland, Auckland 1124, New Zealand
| | - Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical Center, Syracuse, NY 13210, USA
| | - David W Kaczka
- Department of Anesthesia, University of Iowa, Iowa City, IA 52242, USA
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA
- Department of Radiology, University of Iowa, Iowa City, IA 52242, USA
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Nieman GF, Herrmann J, Satalin J, Kollisch-Singule M, Andrews PL, Habashi NM, Tingay DG, Gaver DP, Bates JHT, Kaczka DW. Ratchet recruitment in the acute respiratory distress syndrome: lessons from the newborn cry. Front Physiol 2023; 14:1287416. [PMID: 38028774 PMCID: PMC10646689 DOI: 10.3389/fphys.2023.1287416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/19/2023] [Indexed: 12/01/2023] Open
Abstract
Patients with acute respiratory distress syndrome (ARDS) have few treatment options other than supportive mechanical ventilation. The mortality associated with ARDS remains unacceptably high, and mechanical ventilation itself has the potential to increase mortality further by unintended ventilator-induced lung injury (VILI). Thus, there is motivation to improve management of ventilation in patients with ARDS. The immediate goal of mechanical ventilation in ARDS should be to prevent atelectrauma resulting from repetitive alveolar collapse and reopening. However, a long-term goal should be to re-open collapsed and edematous regions of the lung and reduce regions of high mechanical stress that lead to regional volutrauma. In this paper, we consider the proposed strategy used by the full-term newborn to open the fluid-filled lung during the initial breaths of life, by ratcheting tissues opened over a series of initial breaths with brief expirations. The newborn's cry after birth shares key similarities with the Airway Pressure Release Ventilation (APRV) modality, in which the expiratory duration is sufficiently short to minimize end-expiratory derecruitment. Using a simple computational model of the injured lung, we demonstrate that APRV can slowly open even the most recalcitrant alveoli with extended periods of high inspiratory pressure, while reducing alveolar re-collapse with brief expirations. These processes together comprise a ratchet mechanism by which the lung is progressively recruited, similar to the manner in which the newborn lung is aerated during a series of cries, albeit over longer time scales.
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Affiliation(s)
- Gary F. Nieman
- Department of Surgery, SUNY Upstate Medical Center, Syracuse, NY, United States
| | - Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical Center, Syracuse, NY, United States
| | | | - Penny L. Andrews
- Department of Medicine, University of Maryland, Baltimore, MD, United States
| | - Nader M. Habashi
- Department of Medicine, University of Maryland, Baltimore, MD, United States
| | - David G. Tingay
- Neonatal Research, Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, VIC, Australia
| | - Donald P. Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, United States
| | - Jason H. T. Bates
- Department of Medicine, University of Vermont, Burlington, VT, United States
| | - David W. Kaczka
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States
- Departments of Anesthesia and Radiology, University of Iowa, Iowa City, IA, United States
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Habashi NM, Andrews PL, Bates JH, Camporota L, Nieman GF. Time Controlled Adaptive Ventilation/Airway Pressure Release Ventilation Can be Used Effectively in Patients With or at High Risk of Acute Respiratory Distress Syndrome "Time is the Soul of the World" Pythagoras. Crit Care Med 2023:00003246-990000000-00194. [PMID: 37615521 DOI: 10.1097/ccm.0000000000006018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD
| | - Penny L Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD
| | - Jason H Bates
- Department of Medicine, University of Vermont, Burlington, VT
| | - Luigi Camporota
- Department of Critical Care, Guy's and Saint Thomas' NHS Foundation Trust, London, UK
| | - Gary F Nieman
- Department of Surgery, State University of New York (SUNY) Upstate Medical University, Syracuse, NY
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Nieman GF, Kaczka DW, Andrews PL, Ghosh A, Al-Khalisy H, Camporota L, Satalin J, Herrmann J, Habashi NM. First Stabilize and then Gradually Recruit: A Paradigm Shift in Protective Mechanical Ventilation for Acute Lung Injury. J Clin Med 2023; 12:4633. [PMID: 37510748 PMCID: PMC10380509 DOI: 10.3390/jcm12144633] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/15/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is associated with a heterogeneous pattern of injury throughout the lung parenchyma that alters regional alveolar opening and collapse time constants. Such heterogeneity leads to atelectasis and repetitive alveolar collapse and expansion (RACE). The net effect is a progressive loss of lung volume with secondary ventilator-induced lung injury (VILI). Previous concepts of ARDS pathophysiology envisioned a two-compartment system: a small amount of normally aerated lung tissue in the non-dependent regions (termed "baby lung"); and a collapsed and edematous tissue in dependent regions. Based on such compartmentalization, two protective ventilation strategies have been developed: (1) a "protective lung approach" (PLA), designed to reduce overdistension in the remaining aerated compartment using a low tidal volume; and (2) an "open lung approach" (OLA), which first attempts to open the collapsed lung tissue over a short time frame (seconds or minutes) with an initial recruitment maneuver, and then stabilize newly recruited tissue using titrated positive end-expiratory pressure (PEEP). A more recent understanding of ARDS pathophysiology identifies regional alveolar instability and collapse (i.e., hidden micro-atelectasis) in both lung compartments as a primary VILI mechanism. Based on this understanding, we propose an alternative strategy to ventilating the injured lung, which we term a "stabilize lung approach" (SLA). The SLA is designed to immediately stabilize the lung and reduce RACE while gradually reopening collapsed tissue over hours or days. At the core of SLA is time-controlled adaptive ventilation (TCAV), a method to adjust the parameters of the airway pressure release ventilation (APRV) modality. Since the acutely injured lung at any given airway pressure requires more time for alveolar recruitment and less time for alveolar collapse, SLA adjusts inspiratory and expiratory durations and inflation pressure levels. The TCAV method SLA reverses the open first and stabilize second OLA method by: (i) immediately stabilizing lung tissue using a very brief exhalation time (≤0.5 s), so that alveoli simply do not have sufficient time to collapse. The exhalation duration is personalized and adaptive to individual respiratory mechanical properties (i.e., elastic recoil); and (ii) gradually recruiting collapsed lung tissue using an inflate and brake ratchet combined with an extended inspiratory duration (4-6 s) method. Translational animal studies, clinical statistical analysis, and case reports support the use of TCAV as an efficacious lung protective strategy.
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Affiliation(s)
- Gary F. Nieman
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA;
| | - David W. Kaczka
- Departments of Anesthesia, Radiology and Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Penny L. Andrews
- Department of Medicine, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD 21201, USA
| | - Auyon Ghosh
- Department of Medicine, Upstate Medical University, Syracuse, NY 13210, USA
| | - Hassan Al-Khalisy
- Brody School of Medicine, Department of Internal Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Luigi Camporota
- Department of Adult Critical Care, Guy’s and St Thomas’ NHS Foundation Trust, King’s Partners, St Thomas’ Hospital, London SE1 7EH, UK
| | - Joshua Satalin
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA;
| | - Jacob Herrmann
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Nader M. Habashi
- Department of Medicine, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD 21201, USA
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Bates JHT, Nieman GF, Kollisch-Singule M, Gaver DP. Ventilator-Induced Lung Injury as a Dynamic Balance Between Epithelial Cell Damage and Recovery. Ann Biomed Eng 2023; 51:1052-1062. [PMID: 37000319 DOI: 10.1007/s10439-023-03186-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 03/15/2023] [Indexed: 04/01/2023]
Abstract
Acute respiratory distress syndrome (ARDS) has a high mortality rate that is due in part to ventilator-induced lung injury (VILI). Nevertheless, the majority of patients eventually recover, which means that their innate reparative capacities eventually prevail. Since there are currently no medical therapies for ARDS, minimizing its mortality thus amounts to achieving an optimal balance between spontaneous tissue repair versus the generation of VILI. In order to understand this balance better, we developed a mathematical model of the onset and recovery of VILI that incorporates two hypotheses: (1) a novel multi-hit hypothesis of epithelial barrier failure, and (2) a previously articulated rich-get-richer hypothesis of the interaction between atelectrauma and volutrauma. Together, these concepts explain why VILI appears in a normal lung only after an initial latent period of injurious mechanical ventilation. In addition, they provide a mechanistic explanation for the observed synergy between atelectrauma and volutrauma. The model recapitulates the key features of previously published in vitro measurements of barrier function in an epithelial monolayer and in vivo measurements of lung function in mice subjected to injurious mechanical ventilation. This provides a framework for understanding the dynamic balance between factors responsible for the generation of and recovery from VILI.
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Affiliation(s)
- Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, VT, 05405, USA.
- Department of Medicine, Larner College of Medicine, 149 Beaumont Avenue, Burlington, 05405-0075, USA.
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA
| | | | - Donald P Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
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Ramcharran H, Bates JHT, Satalin J, Blair S, Andrews PL, Gaver DP, Gatto LA, Wang G, Ghosh AJ, Robedee B, Vossler J, Habashi NM, Daphtary N, Kollisch-Singule M, Nieman GF. Protective ventilation in a pig model of acute lung injury: timing is as important as pressure. J Appl Physiol (1985) 2022; 133:1093-1105. [PMID: 36135956 PMCID: PMC9621707 DOI: 10.1152/japplphysiol.00312.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/26/2022] [Accepted: 09/19/2022] [Indexed: 11/22/2022] Open
Abstract
Ventilator-induced lung injury (VILI) is a significant risk for patients with acute respiratory distress syndrome (ARDS). Management of the patient with ARDS is currently dominated by the use of low tidal volume mechanical ventilation, the presumption being that this mitigates overdistension (OD) injury to the remaining normal lung tissue. Evidence exists, however, that it may be more important to avoid cyclic recruitment and derecruitment (RD) of lung units, although the relative roles of OD and RD in VILI remain unclear. Forty pigs had a heterogeneous lung injury induced by Tween instillation and were randomized into four groups (n = 10 each) with higher (↑) or lower (↓) levels of OD and/or RD imposed using airway pressure release ventilation (APRV). OD was increased by setting inspiratory airway pressure to 40 cmH2O and lessened with 28 cmH2O. RD was attenuated using a short duration of expiration (∼0.45 s) and increased with a longer duration (∼1.0 s). All groups developed mild ARDS following injury. RD ↑ OD↑ caused the greatest degree of lung injury as determined by [Formula: see text]/[Formula: see text] ratio (226.1 ± 41.4 mmHg). RD ↑ OD↓ ([Formula: see text]/[Formula: see text]= 333.9 ± 33.1 mmHg) and RD ↓ OD↑ ([Formula: see text]/[Formula: see text] = 377.4 ± 43.2 mmHg) were both moderately injurious, whereas RD ↓ OD↓ ([Formula: see text]/[Formula: see text] = 472.3 ± 22.2 mmHg; P < 0.05) was least injurious. Both tidal volume and driving pressure were essentially identical in the RD ↑ OD↓ and RD ↓ OD↑ groups. We, therefore, conclude that considerations of expiratory time may be at least as important as pressure for safely ventilating the injured lung.NEW & NOTEWORTHY In a large animal model of ARDS, recruitment/derecruitment caused greater VILI than overdistension, whereas both mechanisms together caused severe lung damage. These findings suggest that eliminating cyclic recruitment and derecruitment during mechanical ventilation should be a preeminent management goal for the patient with ARDS. The airway pressure release ventilation (APRV) mode of mechanical ventilation can achieve this if delivered with an expiratory duration (TLow) that is brief enough to prevent derecruitment at end expiration.
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Affiliation(s)
| | | | | | - Sarah Blair
- SUNY Upstate Medical University, Syracuse, New York
| | | | | | | | - Guirong Wang
- SUNY Upstate Medical University, Syracuse, New York
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12
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Herrmann J, Kollisch-Singule M, Satalin J, Nieman GF, Kaczka DW. Assessment of Heterogeneity in Lung Structure and Function During Mechanical Ventilation: A Review of Methodologies. J Eng Sci Med Diagn Ther 2022; 5:040801. [PMID: 35832339 PMCID: PMC9132008 DOI: 10.1115/1.4054386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/13/2022] [Indexed: 06/15/2023]
Abstract
The mammalian lung is characterized by heterogeneity in both its structure and function, by incorporating an asymmetric branching airway tree optimized for maintenance of efficient ventilation, perfusion, and gas exchange. Despite potential benefits of naturally occurring heterogeneity in the lungs, there may also be detrimental effects arising from pathologic processes, which may result in deficiencies in gas transport and exchange. Regardless of etiology, pathologic heterogeneity results in the maldistribution of regional ventilation and perfusion, impairments in gas exchange, and increased work of breathing. In extreme situations, heterogeneity may result in respiratory failure, necessitating support with a mechanical ventilator. This review will present a summary of measurement techniques for assessing and quantifying heterogeneity in respiratory system structure and function during mechanical ventilation. These methods have been grouped according to four broad categories: (1) inverse modeling of heterogeneous mechanical function; (2) capnography and washout techniques to measure heterogeneity of gas transport; (3) measurements of heterogeneous deformation on the surface of the lung; and finally (4) imaging techniques used to observe spatially-distributed ventilation or regional deformation. Each technique varies with regard to spatial and temporal resolution, degrees of invasiveness, risks posed to patients, as well as suitability for clinical implementation. Nonetheless, each technique provides a unique perspective on the manifestations and consequences of mechanical heterogeneity in the diseased lung.
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Affiliation(s)
- Jacob Herrmann
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242
| | | | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210
| | - Gary F. Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY 13210
| | - David W. Kaczka
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242; Department of Anesthesia, University of Iowa, Iowa City, IA 52242; Department of Radiology, University of Iowa, Iowa City, IA 52242
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13
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Andrews P, Shiber J, Madden M, Nieman GF, Camporota L, Habashi NM. Myths and Misconceptions of Airway Pressure Release Ventilation: Getting Past the Noise and on to the Signal. Front Physiol 2022; 13:928562. [PMID: 35957991 PMCID: PMC9358044 DOI: 10.3389/fphys.2022.928562] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/21/2022] [Indexed: 12/16/2022] Open
Abstract
In the pursuit of science, competitive ideas and debate are necessary means to attain knowledge and expose our ignorance. To quote Murray Gell-Mann (1969 Nobel Prize laureate in Physics): “Scientific orthodoxy kills truth”. In mechanical ventilation, the goal is to provide the best approach to support patients with respiratory failure until the underlying disease resolves, while minimizing iatrogenic damage. This compromise characterizes the philosophy behind the concept of “lung protective” ventilation. Unfortunately, inadequacies of the current conceptual model–that focuses exclusively on a nominal value of low tidal volume and promotes shrinking of the “baby lung” - is reflected in the high mortality rate of patients with moderate and severe acute respiratory distress syndrome. These data call for exploration and investigation of competitive models evaluated thoroughly through a scientific process. Airway Pressure Release Ventilation (APRV) is one of the most studied yet controversial modes of mechanical ventilation that shows promise in experimental and clinical data. Over the last 3 decades APRV has evolved from a rescue strategy to a preemptive lung injury prevention approach with potential to stabilize the lung and restore alveolar homogeneity. However, several obstacles have so far impeded the evaluation of APRV’s clinical efficacy in large, randomized trials. For instance, there is no universally accepted standardized method of setting APRV and thus, it is not established whether its effects on clinical outcomes are due to the ventilator mode per se or the method applied. In addition, one distinctive issue that hinders proper scientific evaluation of APRV is the ubiquitous presence of myths and misconceptions repeatedly presented in the literature. In this review we discuss some of these misleading notions and present data to advance scientific discourse around the uses and misuses of APRV in the current literature.
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Affiliation(s)
- Penny Andrews
- R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: Penny Andrews,
| | - Joseph Shiber
- University of Florida College of Medicine, Jacksonville, FL, United States
| | - Maria Madden
- R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Gary F. Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Luigi Camporota
- Department of Adult Critical Care, Guy’s and St Thomas’ NHS Foundation Trust, Health Centre for Human and Applied Physiological Sciences, London, United Kingdom
| | - Nader M. Habashi
- R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
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14
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Yamaguchi E, Yao J, Aymond A, Chrisey DB, Nieman GF, Bates JHT, Gaver DP. Electric Cell-Substrate Impedance Sensing (ECIS) as a Platform for Evaluating Barrier-Function Susceptibility and Damage from Pulmonary Atelectrauma. Biosensors (Basel) 2022; 12:390. [PMID: 35735538 PMCID: PMC9221382 DOI: 10.3390/bios12060390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/27/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
Biophysical insults that either reduce barrier function (COVID-19, smoke inhalation, aspiration, and inflammation) or increase mechanical stress (surfactant dysfunction) make the lung more susceptible to atelectrauma. We investigate the susceptibility and time-dependent disruption of barrier function associated with pulmonary atelectrauma of epithelial cells that occurs in acute respiratory distress syndrome (ARDS) and ventilator-induced lung injury (VILI). This in vitro study was performed using Electric Cell-substrate Impedance Sensing (ECIS) as a noninvasive evaluating technique for repetitive stress stimulus/response on monolayers of the human lung epithelial cell line NCI-H441. Atelectrauma was mimicked through recruitment/derecruitment (RD) of a semi-infinite air bubble to the fluid-occluded micro-channel. We show that a confluent monolayer with a high level of barrier function is nearly impervious to atelectrauma for hundreds of RD events. Nevertheless, barrier function is eventually diminished, and after a critical number of RD insults, the monolayer disintegrates exponentially. Confluent layers with lower initial barrier function are less resilient. These results indicate that the first line of defense from atelectrauma resides with intercellular binding. After disruption, the epithelial layer community protection is diminished and atelectrauma ensues. ECIS may provide a platform for identifying damaging stimuli, ventilation scenarios, or pharmaceuticals that can reduce susceptibility or enhance barrier-function recovery.
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Affiliation(s)
- Eiichiro Yamaguchi
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA; (J.Y.); (A.A.)
| | - Joshua Yao
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA; (J.Y.); (A.A.)
| | - Allison Aymond
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA; (J.Y.); (A.A.)
| | - Douglas B. Chrisey
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA;
| | - Gary F. Nieman
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA;
| | - Jason H. T. Bates
- Department of Medicine, University of Vermont, Burlington, VT 05405, USA;
| | - Donald P. Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA; (J.Y.); (A.A.)
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15
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Kollisch-Singule M, Ramcharran H, Satalin J, Blair S, Gatto LA, Andrews PL, Habashi NM, Nieman GF, Bougatef A. Mechanical Ventilation in Pediatric and Neonatal Patients. Front Physiol 2022; 12:805620. [PMID: 35369685 PMCID: PMC8969224 DOI: 10.3389/fphys.2021.805620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 12/15/2021] [Indexed: 11/30/2022] Open
Abstract
Pediatric acute respiratory distress syndrome (PARDS) remains a significant cause of morbidity and mortality, with mortality rates as high as 50% in children with severe PARDS. Despite this, pediatric lung injury and mechanical ventilation has been poorly studied, with the majority of investigations being observational or retrospective and with only a few randomized controlled trials to guide intensivists. The most recent and universally accepted guidelines for pediatric lung injury are based on consensus opinion rather than objective data. Therefore, most neonatal and pediatric mechanical ventilation practices have been arbitrarily adapted from adult protocols, neglecting the differences in lung pathophysiology, response to injury, and co-morbidities among the three groups. Low tidal volume ventilation has been generally accepted for pediatric patients, even in the absence of supporting evidence. No target tidal volume range has consistently been associated with outcomes, and compliance with delivering specific tidal volume ranges has been poor. Similarly, optimal PEEP has not been well-studied, with a general acceptance of higher levels of FiO2 and less aggressive PEEP titration as compared with adults. Other modes of ventilation including airway pressure release ventilation and high frequency ventilation have not been studied in a systematic fashion and there is too little evidence to recommend supporting or refraining from their use. There have been no consistent outcomes among studies in determining optimal modes or methods of setting them. In this review, the studies performed to date on mechanical ventilation strategies in neonatal and pediatric populations will be analyzed. There may not be a single optimal mechanical ventilation approach, where the best method may simply be one that allows for a personalized approach with settings adapted to the individual patient and disease pathophysiology. The challenges and barriers to conducting well-powered and robust multi-institutional studies will also be addressed, as well as reconsidering outcome measures and study design.
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Affiliation(s)
| | - Harry Ramcharran
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
- *Correspondence: Joshua Satalin,
| | - Sarah Blair
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Louis A. Gatto
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Penny L. Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Nader M. Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Gary F. Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Adel Bougatef
- Independent Researcher, San Antonio, TX, United States
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16
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Oliveira MVD, Magalhães RF, Rocha NN, Fernandes MVS, Antunes MA, Morales MM, Capelozzi VL, Satalin J, Andrews P, Habashi NM, Nieman GF, Rocco PRM, Silva PL. Effects of time-controlled adaptive ventilation on cardiorespiratory parameters and inflammatory response in experimental emphysema. J Appl Physiol (1985) 2022; 132:564-574. [PMID: 34989651 DOI: 10.1152/japplphysiol.00689.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The time-controlled adaptive ventilation (TCAV) method attenuates lung damage in acute respiratory distress syndrome. However, so far, no study has evaluated the impact of the TCAV method on ventilator-induced lung injury (VILI) and cardiac function in emphysema. We hypothesized that the use of the TCAV method to achieve an expiratory flow termination/expiratory peak flow (EFT/EPF) of 25% could reduce VILI and improve right ventricular function in elastase-induced lung emphysema in rats. Five weeks after the last intratracheal instillation of elastase, animals were anesthetized and mechanically ventilated for 1 h using TCAV adjusted to either EFT/EPF 25% or EFT/EPF 75%, the latter often applied in ARDS. Pressure-controlled ventilation (PCV) groups with positive end-expiratory pressure levels similar to positive end-release pressure in TCAV with EFT/EPF 25% and EFT/EPF 75% were also analyzed. Echocardiography and lung ultrasonography were monitored. Lung morphometry, alveolar heterogeneity, and biological markers related to inflammation (interleukin [IL]-6, CINC-1), alveolar pulmonary stretch (amphiregulin), lung matrix damage (metalloproteinase [MMP]-9) were assessed. EFT/EPF 25% reduced respiratory system peak pressure, mean linear intercept, B lines at lung ultrasonography, and increased pulmonary acceleration time/pulmonary ejection time ratio compared with EFT/EPF 75%. The volume fraction of mononuclear cells, neutrophils, and expression of IL-6, CINC-1, amphiregulin, and MMP-9 were lower with EFT/EPF 25% than with EFT/EPF 75%. In conclusion, TCAV with EFT/EPF 25%, compared with EFT/EPF 75%, led to less lung inflammation, hyperinflation, and pulmonary arterial hypertension, which may be a promising strategy for patients with emphysema.
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Affiliation(s)
- Milena Vasconcellos de Oliveira
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel F Magalhães
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nazareth N Rocha
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcos V S Fernandes
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mariana Alves Antunes
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo Marco Morales
- Department of Physiology and Pharmacology, Biomedical Institute, grid.411173.1Fluminense Federal University, Rio de Janeiro, Brazil
| | - Vera Luiza Capelozzi
- Department of Pathology, grid.11899.38University of Sao Paulo, São Paulo, Brazil
| | - Joshua Satalin
- Department of Surgery, grid.411023.5SUNY Upstate Medical University, Syracuse, United States
| | - Penny Andrews
- Department of Surgery, R Adams Cowley Shock Trauma Center, grid.411024.2University of Maryland, Baltimore, Baltimore, United States
| | - Nader M Habashi
- Department of Surgery, Adams Cowley Shock Trauma Center, grid.411024.2University of Maryland, Baltimore, Baltimore, MD, United States
| | - Gary F Nieman
- Department of Surgery, grid.411023.5SUNY Upstate Medical University, Syracuse, New York, United States
| | - Patricia Rieken Macedo Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
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17
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Beretta E, Romanò F, Sancini G, Grotberg JB, Nieman GF, Miserocchi G. Pulmonary Interstitial Matrix and Lung Fluid Balance From Normal to the Acutely Injured Lung. Front Physiol 2021; 12:781874. [PMID: 34987415 PMCID: PMC8720972 DOI: 10.3389/fphys.2021.781874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/02/2021] [Indexed: 01/17/2023] Open
Abstract
This review analyses the mechanisms by which lung fluid balance is strictly controlled in the air-blood barrier (ABB). Relatively large trans-endothelial and trans-epithelial Starling pressure gradients result in a minimal flow across the ABB thanks to low microvascular permeability aided by the macromolecular structure of the interstitial matrix. These edema safety factors are lost when the integrity of the interstitial matrix is damaged. The result is that small Starling pressure gradients, acting on a progressively expanding alveolar barrier with high permeability, generate a high transvascular flow that causes alveolar flooding in minutes. We modeled the trans-endothelial and trans-epithelial Starling pressure gradients under control conditions, as well as under increasing alveolar pressure (Palv) conditions of up to 25 cmH2O. We referred to the wet-to-dry weight (W/D) ratio, a specific index of lung water balance, to be correlated with the functional state of the interstitial structure. W/D averages ∼5 in control and might increase by up to ∼9 in severe edema, corresponding to ∼70% loss in the integrity of the native matrix. Factors buffering edemagenic conditions include: (i) an interstitial capacity for fluid accumulation located in the thick portion of ABB, (ii) the increase in interstitial pressure due to water binding by hyaluronan (the "safety factor" opposing the filtration gradient), and (iii) increased lymphatic flow. Inflammatory factors causing lung tissue damage include those of bacterial/viral and those of sterile nature. Production of reactive oxygen species (ROS) during hypoxia or hyperoxia, or excessive parenchymal stress/strain [lung overdistension caused by patient self-induced lung injury (P-SILI)] can all cause excessive inflammation. We discuss the heterogeneity of intrapulmonary distribution of W/D ratios. A W/D ∼6.5 has been identified as being critical for the transition to severe edema formation. Increasing Palv for W/D > 6.5, both trans-endothelial and trans-epithelial gradients favor filtration leading to alveolar flooding. Neither CT scan nor ultrasound can identify this initial level of lung fluid balance perturbation. A suggestion is put forward to identify a non-invasive tool to detect the earliest stages of perturbation of lung fluid balance before the condition becomes life-threatening.
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Affiliation(s)
- Egidio Beretta
- Department of Medicine and Surgery, School of Medicine and Surgery, Università degli Studi di Milano-Bicocca, Monza, Italy
| | - Francesco Romanò
- Univ. Lille, CNRS, ONERA, Arts et Métiers, Centrale Lille, FRE 2017-LMFL-Laboratoire de Mécanique des Fluides de Lille – Kampé de Fériet, Lille, France
| | - Giulio Sancini
- Department of Medicine and Surgery, School of Medicine and Surgery, Università degli Studi di Milano-Bicocca, Monza, Italy
| | - James B. Grotberg
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Gary F. Nieman
- Department of Surgery, State University of New York Upstate Medical University, Syracuse, NY, United States
| | - Giuseppe Miserocchi
- Department of Medicine and Surgery, School of Medicine and Surgery, Università degli Studi di Milano-Bicocca, Monza, Italy
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18
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Sayed Ahmed HA, Merrell E, Ismail M, Joudeh AI, Riley JB, Shawkat A, Habeb H, Darling E, Goweda RA, Shehata MH, Amin H, Nieman GF, Aiash H. Rationales and uncertainties for aspirin use in COVID-19: a narrative review. Fam Med Community Health 2021; 9:fmch-2020-000741. [PMID: 33879541 PMCID: PMC8061559 DOI: 10.1136/fmch-2020-000741] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Objectives To review the pathophysiology of COVID-19 disease, potential aspirin targets on this pathogenesis and the potential role of aspirin in patients with COVID-19. Design Narrative review. Setting The online databases PubMed, OVID Medline and Cochrane Library were searched using relevant headlines from 1 January 2016 to 1 January 2021. International guidelines from relevant societies, journals and forums were also assessed for relevance. Participants Not applicable. Results A review of the selected literature revealed that clinical deterioration in COVID-19 is attributed to the interplay between endothelial dysfunction, coagulopathy and dysregulated inflammation. Aspirin has anti-inflammatory effects, antiplatelet aggregation, anticoagulant properties as well as pleiotropic effects on endothelial function. During the COVID-19 pandemic, low-dose aspirin is used effectively in secondary prevention of atherosclerotic cardiovascular disease, prevention of venous thromboembolism after total hip or knee replacement, prevention of pre-eclampsia and postdischarge treatment for multisystem inflammatory syndrome in children. Prehospital low-dose aspirin therapy may reduce the risk of intensive care unit admission and mechanical ventilation in hospitalised patients with COVID-19, whereas aspirin association with mortality is still debatable. Conclusion The authors recommend a low-dose aspirin regimen for primary prevention of arterial thromboembolism in patients aged 40–70 years who are at high atherosclerotic cardiovascular disease risk, or an intermediate risk with a risk-enhancer and have a low risk of bleeding. Aspirin’s protective roles in COVID-19 associated with acute lung injury, vascular thrombosis without previous cardiovascular disease and mortality need further randomised controlled trials to establish causal conclusions.
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Affiliation(s)
- Hazem A Sayed Ahmed
- Department of Family Medicine, Suez Canal University Faculty of Medicine, Ismailia, Egypt
| | - Eric Merrell
- Department of Medicine, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Mansoura Ismail
- Department of Family Medicine, Suez Canal University Faculty of Medicine, Ismailia, Egypt
| | - Anwar I Joudeh
- Department of Internal Medicine, The University of Jordan, Amman, Jordan
| | - Jeffrey B Riley
- Department of Cardiovascular Perfusion, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Ahmed Shawkat
- Department of Critical Care, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Hanan Habeb
- Egypt Ministry of Health and Population, Cairo, Egypt
| | - Edward Darling
- Department of Cardiovascular Perfusion, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Reda A Goweda
- Department of Family Medicine, Suez Canal University Faculty of Medicine, Ismailia, Egypt.,Department of Community Medicine, Umm Al-Qura University College of Medicine, Makkah, Saudi Arabia
| | - Mohamed H Shehata
- Department of Family and Community Medicine, Arabian Gulf University College of Medicine and Medical Science, Manama, Bahrain
| | - Hossam Amin
- Department of Critical Care, New York Medical College, Valhalla, New York, USA
| | - Gary F Nieman
- Department of Surgery, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Hani Aiash
- Department of Family Medicine, Suez Canal University Faculty of Medicine, Ismailia, Egypt.,Department of Cardiovascular Perfusion, State University of New York Upstate Medical University, Syracuse, New York, USA.,Department of Surgery, State University of New York Upstate Medical University, Syracuse, New York, USA
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19
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Abstract
OBJECTIVES Elucidate how the degree of ventilator-induced lung injury due to atelectrauma that is produced in the injured lung during mechanical ventilation is determined by both the timing and magnitude of the airway pressure profile. DESIGN A computational model of the injured lung provides a platform for exploring how mechanical ventilation parameters potentially modulate atelectrauma and volutrauma. This model incorporates the time dependence of lung recruitment and derecruitment, and the time-constant of lung emptying during expiration as determined by overall compliance and resistance of the respiratory system. SETTING Computational model. SUBJECTS Simulated scenarios representing patients with both normal and acutely injured lungs. MEASUREMENTS AND MAIN RESULTS Protective low-tidal volume ventilation (Low-Vt) of the simulated injured lung avoided atelectrauma through the elevation of positive end-expiratory pressure while maintaining fixed tidal volume and driving pressure. In contrast, airway pressure release ventilation avoided atelectrauma by incorporating a very brief expiratory duration () that both prevents enough time for derecruitment and limits the minimum alveolar pressure prior to inspiration. Model simulations demonstrated that has an effective threshold value below which airway pressure release ventilation is safe from atelectrauma while maintaining a tidal volume and driving pressure comparable with those of Low-Vt. This threshold is strongly influenced by the time-constant of lung-emptying. CONCLUSIONS Low-Vt and airway pressure release ventilation represent markedly different strategies for the avoidance of ventilator-induced lung injury, primarily involving the manipulation of positive end-expiratory pressure and , respectively. can be based on exhalation flow values, which may provide a patient-specific approach to protective ventilation.
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Affiliation(s)
- Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, VT
| | - Donald P Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA
| | - Nader M Habashi
- R Adams Cowley Shock Trauma Center, Department of Medicine, University of Maryland, Baltimore, MD
| | - Gary F Nieman
- Department of Surgery, Upstate Medical University, Syracuse, NY
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20
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Gaver DP, Nieman GF, Gatto LA, Cereda M, Habashi NM, Bates JHT. The POOR Get POORer: A Hypothesis for the Pathogenesis of Ventilator-induced Lung Injury. Am J Respir Crit Care Med 2020; 202:1081-1087. [PMID: 33054329 DOI: 10.1164/rccm.202002-0453cp] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Protective ventilation strategies for the injured lung currently revolve around the use of low Vt, ostensibly to avoid volutrauma, together with positive end-expiratory pressure to increase the fraction of open lung and reduce atelectrauma. Protective ventilation is currently applied in a one-size-fits-all manner, and although this practical approach has reduced acute respiratory distress syndrome deaths, mortality is still high and improvements are at a standstill. Furthermore, how to minimize ventilator-induced lung injury (VILI) for any given lung remains controversial and poorly understood. Here we present a hypothesis of VILI pathogenesis that potentially serves as a basis upon which minimally injurious ventilation strategies might be developed. This hypothesis is based on evidence demonstrating that VILI begins in isolated lung regions manifesting a Permeability-Originated Obstruction Response (POOR) in which alveolar leak leads to surfactant dysfunction and increases local tissue stresses. VILI progresses topographically outward from these regions in a POOR-get-POORer fashion unless steps are taken to interrupt it. We propose that interrupting the POOR-get-POORer progression of lung injury relies on two principles: 1) open the lung to minimize the presence of heterogeneity-induced stress concentrators that are focused around the regions of atelectasis, and 2) ventilate in a patient-dependent manner that minimizes the number of lung units that close during each expiration so that they are not forced to rerecruit during the subsequent inspiration. These principles appear to be borne out in both patient and animal studies in which expiration is terminated before derecruitment of lung units has enough time to occur.
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Affiliation(s)
- Donald P Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care and.,Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nader M Habashi
- R Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, Maryland; and
| | - Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, Vermont
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21
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Kollisch-Singule M, Satalin J, Blair SJ, Andrews PL, Gatto LA, Nieman GF, Habashi NM. Mechanical Ventilation Lessons Learned From Alveolar Micromechanics. Front Physiol 2020; 11:233. [PMID: 32265735 PMCID: PMC7105828 DOI: 10.3389/fphys.2020.00233] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/28/2020] [Indexed: 01/05/2023] Open
Abstract
Morbidity and mortality associated with lung injury remains disappointingly unchanged over the last two decades, in part due to the current reliance on lung macro-parameters set on the ventilator instead of considering the micro-environment and the response of the alveoli and alveolar ducts to ventilator adjustments. The response of alveoli and alveolar ducts to mechanical ventilation modes cannot be predicted with current bedside methods of assessment including lung compliance, oxygenation, and pressure-volume curves. Alveolar tidal volumes (Vt) are less determined by the Vt set on the mechanical ventilator and more dependent on the number of recruited alveoli available to accommodate that Vt and their heterogeneous mechanical properties, such that high lung Vt can lead to a low alveolar Vt and low Vt can lead to high alveolar Vt. The degree of alveolar heterogeneity that exists cannot be predicted based on lung calculations that average the individual alveolar Vt and compliance. Finally, the importance of time in promoting alveolar stability, specifically the inspiratory and expiratory times set on the ventilator, are currently under-appreciated. In order to improve outcomes related to lung injury, the respiratory physiology of the individual patient, specifically at the level of the alveolus, must be targeted. With experimental data, this review highlights some of the known mechanical ventilation adjustments that are helpful or harmful at the level of the alveolus.
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Affiliation(s)
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Sarah J Blair
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Penny L Andrews
- Department of Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD, United States
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States.,Department of Biological Sciences, SUNY Cortland, Cortland, NY, United States
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Nader M Habashi
- Department of Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD, United States
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22
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Nieman GF, Al-Khalisy H, Kollisch-Singule M, Satalin J, Blair S, Trikha G, Andrews P, Madden M, Gatto LA, Habashi NM. A Physiologically Informed Strategy to Effectively Open, Stabilize, and Protect the Acutely Injured Lung. Front Physiol 2020; 11:227. [PMID: 32265734 PMCID: PMC7096584 DOI: 10.3389/fphys.2020.00227] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 02/27/2020] [Indexed: 12/16/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) causes a heterogeneous lung injury and remains a serious medical problem, with one of the only treatments being supportive care in the form of mechanical ventilation. It is very difficult, however, to mechanically ventilate the heterogeneously damaged lung without causing secondary ventilator-induced lung injury (VILI). The acutely injured lung becomes time and pressure dependent, meaning that it takes more time and pressure to open the lung, and it recollapses more quickly and at higher pressure. Current protective ventilation strategies, ARDSnet low tidal volume (LVt) and the open lung approach (OLA), have been unsuccessful at further reducing ARDS mortality. We postulate that this is because the LVt strategy is constrained to ventilating a lung with a heterogeneous mix of normal and focalized injured tissue, and the OLA, although designed to fully open and stabilize the lung, is often unsuccessful at doing so. In this review we analyzed the pathophysiology of ARDS that renders the lung susceptible to VILI. We also analyzed the alterations in alveolar and alveolar duct mechanics that occur in the acutely injured lung and discussed how these alterations are a key mechanism driving VILI. Our analysis suggests that the time component of each mechanical breath, at both inspiration and expiration, is critical to normalize alveolar mechanics and protect the lung from VILI. Animal studies and a meta-analysis have suggested that the time-controlled adaptive ventilation (TCAV) method, using the airway pressure release ventilation mode, eliminates the constraints of ventilating a lung with heterogeneous injury, since it is highly effective at opening and stabilizing the time- and pressure-dependent lung. In animal studies it has been shown that by “casting open” the acutely injured lung with TCAV we can (1) reestablish normal expiratory lung volume as assessed by direct observation of subpleural alveoli; (2) return normal parenchymal microanatomical structural support, known as alveolar interdependence and parenchymal tethering, as assessed by morphometric analysis of lung histology; (3) facilitate regeneration of normal surfactant function measured as increases in surfactant proteins A and B; and (4) significantly increase lung compliance, which reduces the pathologic impact of driving pressure and mechanical power at any given tidal volume.
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Affiliation(s)
- Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Hassan Al-Khalisy
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States.,Department of Medicine, SUNY Upstate Medical University, Syracuse, NY, United States
| | | | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Sarah Blair
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Girish Trikha
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States.,Department of Medicine, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Maria Madden
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, United States.,Department of Biological Sciences, SUNY Cortland, Cortland, NY, United States
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, United States
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Nieman GF, Gatto LA, Andrews P, Satalin J, Camporota L, Daxon B, Blair SJ, Al-Khalisy H, Madden M, Kollisch-Singule M, Aiash H, Habashi NM. Prevention and treatment of acute lung injury with time-controlled adaptive ventilation: physiologically informed modification of airway pressure release ventilation. Ann Intensive Care 2020; 10:3. [PMID: 31907704 PMCID: PMC6944723 DOI: 10.1186/s13613-019-0619-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/23/2019] [Indexed: 12/16/2022] Open
Abstract
Mortality in acute respiratory distress syndrome (ARDS) remains unacceptably high at approximately 39%. One of the only treatments is supportive: mechanical ventilation. However, improperly set mechanical ventilation can further increase the risk of death in patients with ARDS. Recent studies suggest that ventilation-induced lung injury (VILI) is caused by exaggerated regional lung strain, particularly in areas of alveolar instability subject to tidal recruitment/derecruitment and stress-multiplication. Thus, it is reasonable to expect that if a ventilation strategy can maintain stable lung inflation and homogeneity, regional dynamic strain would be reduced and VILI attenuated. A time-controlled adaptive ventilation (TCAV) method was developed to minimize dynamic alveolar strain by adjusting the delivered breath according to the mechanical characteristics of the lung. The goal of this review is to describe how the TCAV method impacts pathophysiology and protects lungs with, or at high risk of, acute lung injury. We present work from our group and others that identifies novel mechanisms of VILI in the alveolar microenvironment and demonstrates that the TCAV method can reduce VILI in translational animal ARDS models and mortality in surgical/trauma patients. Our TCAV method utilizes the airway pressure release ventilation (APRV) mode and is based on opening and collapsing time constants, which reflect the viscoelastic properties of the terminal airspaces. Time-controlled adaptive ventilation uses inspiratory and expiratory time to (1) gradually “nudge” alveoli and alveolar ducts open with an extended inspiratory duration and (2) prevent alveolar collapse using a brief (sub-second) expiratory duration that does not allow time for alveolar collapse. The new paradigm in TCAV is configuring each breath guided by the previous one, which achieves real-time titration of ventilator settings and minimizes instability induced tissue damage. This novel methodology changes the current approach to mechanical ventilation, from arbitrary to personalized and adaptive. The outcome of this approach is an open and stable lung with reduced regional strain and greater lung protection.
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Affiliation(s)
- Gary F Nieman
- Dept of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Louis A Gatto
- Dept of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Penny Andrews
- Multi-trauma Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, 22 South Greene Street, Baltimore, MD, USA
| | - Joshua Satalin
- Dept of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA.
| | - Luigi Camporota
- Department of Critical Care, Guy's and St, Thomas' NHS Foundation Trust, Westminster Bridge Rd, London, SE1 7EH, UK
| | - Benjamin Daxon
- Dept of Anesthesiology and Perioperative Medicine, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905, USA
| | - Sarah J Blair
- Dept of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Hassan Al-Khalisy
- Dept of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Maria Madden
- Multi-trauma Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, 22 South Greene Street, Baltimore, MD, USA
| | | | - Hani Aiash
- Dept of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA.,Department of Clinical Perfusion, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Nader M Habashi
- Multi-trauma Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, 22 South Greene Street, Baltimore, MD, USA
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24
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Kazemi A, Louis B, Isabey D, Nieman GF, Gatto LA, Satalin J, Baker S, Grotberg JB, Filoche M. Surfactant delivery in rat lungs: Comparing 3D geometrical simulation model with experimental instillation. PLoS Comput Biol 2019; 15:e1007408. [PMID: 31622332 PMCID: PMC6818804 DOI: 10.1371/journal.pcbi.1007408] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 10/29/2019] [Accepted: 09/18/2019] [Indexed: 11/24/2022] Open
Abstract
Surfactant Replacement Therapy (SRT), which involves instillation of a liquid-surfactant mixture directly into the lung airway tree, is a major therapeutic treatment in neonatal patients with respiratory distress syndrome (RDS). This procedure has proved to be remarkably effective in premature newborns, inducing a five-fold decrease of mortality in the past 35 years. Disappointingly, its use in adults for treating acute respiratory distress syndrome (ARDS) experienced initial success followed by failures. Our recently developed numerical model has demonstrated that transition from success to failure of SRT in adults could, in fact, have a fluid mechanical origin that is potentially reversible. Here, we present the first numerical simulations of surfactant delivery into a realistic asymmetric conducting airway tree of the rat lung and compare them with experimental results. The roles of dose volume (VD), flow rate, and multiple aliquot delivery are investigated. We find that our simulations of surfactant delivery in rat lungs are in good agreement with our experimental data. In particular, we show that the monopodial architecture of the rat airway tree plays a major role in surfactant delivery, contributing to the poor homogeneity of the end distribution of surfactant. In addition, we observe that increasing VD increases the amount of surfactant delivered to the acini after losing a portion to coating the involved airways, the coating cost volume, VCC. Finally, we quantitatively assess the improvement resulting from a multiple aliquot delivery, a method sometimes employed clinically, and find that a much larger fraction of surfactant reaches the alveolar regions in this case. This is the first direct qualitative and quantitative comparison of our numerical model with experimental studies, which enhances our previous predictions in adults and neonates while providing a tool for predicting, engineering, and optimizing patient-specific surfactant delivery in complex situations.
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Affiliation(s)
- Alireza Kazemi
- Physique de la Matière Condensée, École Polytechnique, CNRS, Institut Polytechnique de Paris, Palaiseau, France
| | - Bruno Louis
- ERL 7000 CNRS and IMRB U955 Inserm, Université Paris Est Créteil, Créteil, France
| | - Daniel Isabey
- ERL 7000 CNRS and IMRB U955 Inserm, Université Paris Est Créteil, Créteil, France
| | - Gary F. Nieman
- Department of Surgery, Upstate Medical University, Syracuse, New York, United States of America
| | - Louis A. Gatto
- Department of Surgery, Upstate Medical University, Syracuse, New York, United States of America
| | - Joshua Satalin
- Department of Surgery, Upstate Medical University, Syracuse, New York, United States of America
| | - Sarah Baker
- Department of Surgery, Upstate Medical University, Syracuse, New York, United States of America
| | - James B. Grotberg
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marcel Filoche
- Physique de la Matière Condensée, École Polytechnique, CNRS, Institut Polytechnique de Paris, Palaiseau, France
- ERL 7000 CNRS and IMRB U955 Inserm, Université Paris Est Créteil, Créteil, France
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25
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Kollisch-Singule MC, Jain SV, Andrews PL, Satalin J, Gatto LA, Villar J, De Backer D, Gattinoni L, Nieman GF, Habashi NM. Last Word on Viewpoint: Looking beyond macrovenitlatory parameters and rethinking ventilator-induced lung injury. J Appl Physiol (1985) 2019; 124:1220-1221. [PMID: 29745822 DOI: 10.1152/japplphysiol.00049.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
| | - Sumeet V Jain
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York
| | - Penny L Andrews
- Department of Trauma Critical Care Medicine, R. Adams Cowley Shock Trauma Center, University of Maryland School of Medicine , Baltimore, Maryland
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York.,Department of Biological Sciences, SUNY Cortland, New York
| | - Jesús Villar
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III , Madrid , Spain.,Research Unit, Hospital Universitario Dr. Negrin , Las Palmas de Gran Canaria , Spain
| | - Daniel De Backer
- Department of Intensive Care, CHIREC Hospitals, Université Libre de Bruxelles , Brussels , Belgium
| | - Luciano Gattinoni
- Department of Anesthesia and Intensive Care, Georg-August-Universität, Göttingen , Germany
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R. Adams Cowley Shock Trauma Center, University of Maryland School of Medicine , Baltimore, Maryland
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Mahajan M, DiStefano D, Satalin J, Andrews P, Al-Khalisy H, Baker S, Gatto LA, Nieman GF, Habashi NM. Time-controlled adaptive ventilation (TCAV) accelerates simulated mucus clearance via increased expiratory flow rate. Intensive Care Med Exp 2019; 7:27. [PMID: 31098761 PMCID: PMC6522588 DOI: 10.1186/s40635-019-0250-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/29/2019] [Indexed: 01/31/2023] Open
Abstract
Background Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in intensive care units. Distal airway mucus clearance has been shown to reduce VAP incidence. Studies suggest that mucus clearance is enhanced when the rate of expiratory flow is greater than inspiratory flow. The time-controlled adaptive ventilation (TCAV) protocol using the airway pressure release ventilation (APRV) mode has a significantly increased expiratory relative to inspiratory flow rate, as compared with the Acute Respiratory Distress Syndrome Network (ARDSnet) protocol using the conventional ventilation mode of volume assist control (VAC). We hypothesized the TCAV protocol would be superior to the ARDSnet protocol at clearing mucus by a mechanism of net flow in the expiratory direction. Methods Preserved pig lungs fitted with an endotracheal tube (ETT) were used as a model to study the effect of multiple combinations of peak inspiratory (IPF) and peak expiratory flow rate (EPF) on simulated mucus movement within the ETT. Mechanical ventilation was randomized into 6 groups (n = 10 runs/group): group 1—TCAV protocol settings with an end-expiratory pressure (PLow) of 0 cmH2O and PHigh 25 cmH2O, group 2—modified TCAV protocol with increased PLow 5 cmH2O and PHigh 25 cmH2O, group 3—modified TCAV with PLow 10 cmH2O and PHigh 25 cmH2O, group 4—ARDSnet protocol using low tidal volume (LTV) and PEEP 0 cmH2O, group 5—ARDSnet protocol using LTV and PEEP 10 cmH2O, and group 6—ARDSnet protocol using LTV and PEEP 20 cmH2O. PEEP of ARDSnet is analogous to PLow of TCAV. Proximal (towards the ventilator) mucus movement distance was recorded after 1 min of ventilation in each group. Results The TCAV protocol groups 1, 2, and 3 generated significantly greater peak expiratory flow (EPF 51.3 L/min, 46.8 L/min, 36.8 L/min, respectively) as compared to the ARDSnet protocol groups 4, 5, and 6 (32.9 L/min, 23.5 L/min, and 23.2 L/min, respectively) (p < 0.001). The TCAV groups also demonstrated the greatest proximal mucus movement (7.95 cm/min, 5.8 cm/min, 1.9 cm/min) (p < 0.01). All ARDSnet protocol groups (4–6) had zero proximal mucus movement (0 cm/min). Conclusions The TCAV protocol groups promoted the greatest proximal movement of simulated mucus as compared to the ARDSnet protocol groups in this excised lung model. The TCAV protocol settings resulted in the highest EPF and the greatest proximal movement of mucus. Increasing PLow reduced proximal mucus movement. We speculate that proximal mucus movement is driven by EPF when EPF is greater than IPF, creating a net force in the proximal direction.
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Affiliation(s)
- Melissa Mahajan
- Department of Surgery, SUNY Upstate Medical University, 750 East Adams St., 766 Irving Avenue, Syracuse, NY, 13210, USA
| | - David DiStefano
- Department of Surgery, SUNY Upstate Medical University, 750 East Adams St., 766 Irving Avenue, Syracuse, NY, 13210, USA
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 East Adams St., 766 Irving Avenue, Syracuse, NY, 13210, USA.
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD, 21201, USA
| | - Hassan Al-Khalisy
- Department of Surgery, SUNY Upstate Medical University, 750 East Adams St., 766 Irving Avenue, Syracuse, NY, 13210, USA
| | - Sarah Baker
- Department of Surgery, SUNY Upstate Medical University, 750 East Adams St., 766 Irving Avenue, Syracuse, NY, 13210, USA
| | - Louis A Gatto
- Department of Biological Sciences, SUNY Cortland, 22 Graham Avenue, Cortland, NY, 13045, USA
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 East Adams St., 766 Irving Avenue, Syracuse, NY, 13210, USA
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD, 21201, USA
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Kollisch-Singule M, Andrews P, Satalin J, Gatto LA, Nieman GF, Habashi NM. The time-controlled adaptive ventilation protocol: mechanistic approach to reducing ventilator-induced lung injury. Eur Respir Rev 2019; 28:28/152/180126. [PMID: 30996041 DOI: 10.1183/16000617.0126-2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 02/16/2019] [Indexed: 11/05/2022] Open
Abstract
Airway pressure release ventilation (APRV) is a ventilator mode that has previously been considered a rescue mode, but has gained acceptance as a primary mode of ventilation. In clinical series and experimental animal models of extrapulmonary acute respiratory distress syndrome (ARDS), the early application of APRV was able to prevent the development of ARDS. Recent experimental evidence has suggested mechanisms by which APRV, using the time-controlled adaptive ventilation (TCAV) protocol, may reduce lung injury, including: 1) an improvement in alveolar recruitment and homogeneity; 2) reduction in alveolar and alveolar duct micro-strain and stress-risers; 3) reduction in alveolar tidal volumes; and 4) recruitment of the chest wall by combating increased intra-abdominal pressure. This review examines these studies and discusses our current understanding of the pleiotropic mechanisms by which TCAV protects the lung. APRV set according to the TCAV protocol has been misunderstood and this review serves to highlight the various protective physiological and mechanical effects it has on the lung, so that its clinical application may be broadened.
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Affiliation(s)
| | - Penny Andrews
- Dept of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joshua Satalin
- Dept of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Louis A Gatto
- Dept of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA.,Dept of Biological Sciences, SUNY Cortland, Cortland, NY, USA
| | - Gary F Nieman
- Dept of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Nader M Habashi
- Dept of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, USA
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Roy SK, Meng Q, Sadowitz BD, Kollisch-Singule M, Yepuri N, Satalin J, Gatto LA, Nieman GF, Cooney RN, Clark D. Enteral administration of bacteria fermented formula in newborn piglets: A high fidelity model for necrotizing enterocolitis (NEC). PLoS One 2018; 13:e0201172. [PMID: 30036384 PMCID: PMC6056052 DOI: 10.1371/journal.pone.0201172] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 07/10/2018] [Indexed: 12/15/2022] Open
Abstract
Objective To develop an animal model which replicates neonatal NEC and characterizes the importance of bacterial fermentation of formula and short chain fatty acids (SCFAs) in its pathogenesis. Background NEC is a severe form of intestinal inflammation in preterm neonates and current models do not reproduce the human condition. Methods Three groups of newborn piglets: Formula alone (FO), Bacteria alone (E.coli: BO) and E.coli-fermented formula (FF) were anesthetized, instrumented and underwent post-pyloric injection of formula, bacteria or fermented-formula. SCFA levels were measured by gas chromatography-mass spectrometry. At 6 h bowel appearance was assessed, histologic and molecular analysis of intestine were performed. Gut inflammation (p65 NF-κB, TLR4, TNF-α, IL-1β), apoptosis (cleaved caspase-3, BAX, apoptosis) and tight junction proteins (claudin-2, occludin) were measured. Results SCFAs were increased in FF. Small bowel from FF piglet’s demonstrated inflammation, coagulative necrosis and pneumatosis resembling human NEC. Histologic gut injury (injury score, mast cell activation) were increased by Bacteria, but more severe in FF piglets. Intestinal expression of p65 NF-κB, NF-κB activation, TNF-α and IL-1β were increased in BO and markedly increased in the FF group (P<0.05 vs. FO). Intestine from Bacteria piglets demonstrated increased apoptotic index, pro-apoptotic protein expression and decreased tight junction proteins. These changes were more severe in FF piglets. Conclusions Our piglet model demonstrates the findings of NEC in human neonates: systemic acidosis, intestinal inflammation, pneumatosis and portal venous gas. Bacteria alone can initiate intestinal inflammation, injury and apoptosis, but bacterial fermentation of formula generates SCFAs which contribute to the pathogenesis of NEC.
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Affiliation(s)
- Shreyas K. Roy
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Qinghe Meng
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Benjamin D. Sadowitz
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Michaela Kollisch-Singule
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Natesh Yepuri
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Joshua Satalin
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Louis A. Gatto
- SUNY Cortland, Department of Biology, Cortland, New York, United States of America
| | - Gary F. Nieman
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
| | - Robert N. Cooney
- SUNY Upstate Medical University, Department of Surgery, Syracuse, New York, United States of America
- * E-mail:
| | - David Clark
- Albany Medical Center, Department of Pediatrics, Albany, New York, United States of America
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Nieman GF, Andrews P, Satalin J, Wilcox K, Kollisch-Singule M, Madden M, Aiash H, Blair SJ, Gatto LA, Habashi NM. Acute lung injury: how to stabilize a broken lung. Crit Care 2018; 22:136. [PMID: 29793554 PMCID: PMC5968707 DOI: 10.1186/s13054-018-2051-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The pathophysiology of acute respiratory distress syndrome (ARDS) results in heterogeneous lung collapse, edema-flooded airways and unstable alveoli. These pathologic alterations in alveolar mechanics (i.e. dynamic change in alveolar size and shape with each breath) predispose the lung to secondary ventilator-induced lung injury (VILI). It is our viewpoint that the acutely injured lung can be recruited and stabilized with a mechanical breath until it heals, much like casting a broken bone until it mends. If the lung can be "casted" with a mechanical breath, VILI could be prevented and ARDS incidence significantly reduced.
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Affiliation(s)
- Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA
| | - Penny Andrews
- Department of Biological Sciences, SUNY Cortland, Cortland, NY, USA
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Kailyn Wilcox
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA
| | - Michaela Kollisch-Singule
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA
| | - Maria Madden
- Department of Biological Sciences, SUNY Cortland, Cortland, NY, USA
| | - Hani Aiash
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA
| | - Sarah J Blair
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.,Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nader M Habashi
- Department of Biological Sciences, SUNY Cortland, Cortland, NY, USA
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Hasan D, Satalin J, van der Zee P, Kollisch-Singule M, Blankman P, Shono A, Somhorst P, den Uil C, Meeder H, Kotani T, Nieman GF. Excessive Extracellular ATP Desensitizes P2Y2 and P2X4 ATP Receptors Provoking Surfactant Impairment Ending in Ventilation-Induced Lung Injury. Int J Mol Sci 2018; 19:ijms19041185. [PMID: 29652806 PMCID: PMC5979391 DOI: 10.3390/ijms19041185] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/08/2018] [Accepted: 04/10/2018] [Indexed: 12/16/2022] Open
Abstract
Stretching the alveolar epithelial type I (AT I) cells controls the intercellular signaling for the exocytosis of surfactant by the AT II cells through the extracellular release of adenosine triphosphate (ATP) (purinergic signaling). Extracellular ATP is cleared by extracellular ATPases, maintaining its homeostasis and enabling the lung to adapt the exocytosis of surfactant to the demand. Vigorous deformation of the AT I cells by high mechanical power ventilation causes a massive release of extracellular ATP beyond the clearance capacity of the extracellular ATPases. When extracellular ATP reaches levels >100 μM, the ATP receptors of the AT II cells become desensitized and surfactant impairment is initiated. The resulting alteration in viscoelastic properties and in alveolar opening and collapse time-constants leads to alveolar collapse and the redistribution of inspired air from the alveoli to the alveolar ducts, which become pathologically dilated. The collapsed alveoli connected to these dilated alveolar ducts are subject to a massive strain, exacerbating the ATP release. After reaching concentrations >300 μM extracellular ATP acts as a danger-associated molecular pattern, causing capillary leakage, alveolar space edema, and further deactivation of surfactant by serum proteins. Decreasing the tidal volume to 6 mL/kg or less at this stage cannot prevent further lung injury.
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Affiliation(s)
- Djo Hasan
- Mobile Intensive Care Unit Zuid-West Nederland, 3062 NW Rotterdam, The Netherlands.
- Department of Surgery, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | - Joshua Satalin
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA.
| | - Philip van der Zee
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | | | - Paul Blankman
- Department of Anesthesiology, Universitair Medisch Centrum Utrecht, 3584 CX Utrecht, The Netherlands.
| | - Atsuko Shono
- Department of Anesthesiology, Shimane University, Izumo, Shimane Prefecture 693-0021, Japan.
| | - Peter Somhorst
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | - Corstiaan den Uil
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
- Department of Cardiology, Erasmus MC, Erasmus Universiteit Rotterdam, 3062 PA Rotterdam, The Netherlands.
| | - Han Meeder
- Mobile Intensive Care Unit Zuid-West Nederland, 3062 NW Rotterdam, The Netherlands.
- Adult Intensive Care Unit, Erasmus MC, Erasmus Universiteit Rotterdam, 3015 CE Rotterdam, The Netherlands.
| | - Toru Kotani
- Department of Anesthesiology and Critical Care Medicine, Showa University, School of Medicine, Tokyo 142-8666, Japan.
| | - Gary F Nieman
- Department of Surgery, Upstate Medical University, Syracuse, NY 13210, USA.
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Nieman GF, Satalin J, Kollisch-Singule M, Andrews P, Aiash H, Habashi NM, Gatto LA. Reply to Drs. Monjezi and Jamaati: Dynamic alveolar mechanics are more than a soap bubble on a capillary tube. J Appl Physiol (1985) 2018; 124:525. [DOI: 10.1152/japplphysiol.00845.2017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | | | - Penny Andrews
- R Adams Shock Cowley Trauma Center, Baltimore, Maryland
| | - Hani Aiash
- SUNY Upstate Medical University, Syracuse, New York
- Suez Canal University, Egypt
| | | | - Louis A. Gatto
- SUNY Upstate Medical University, Syracuse, New York
- SUNY Cortland, Cortland, New York
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Kollisch-Singule MC, Jain SV, Andrews PL, Satalin J, Gatto LA, Villar J, De Backer D, Gattinoni L, Nieman GF, Habashi NM. Looking beyond macroventilatory parameters and rethinking ventilator-induced lung injury. J Appl Physiol (1985) 2017; 124:1214-1218. [PMID: 29146685 DOI: 10.1152/japplphysiol.00412.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
| | - Sumeet V Jain
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York
| | - Penny L Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine , Baltimore, Maryland
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York.,Department of Biological Sciences, SUNY Cortland, Cortland, New York
| | - Jesús Villar
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III , Madrid , Spain.,Research Unit, Hospital Universitario Dr. Negrin , Las Palmas de Gran Canaria , Spain
| | - Daniel De Backer
- Department of Intensive Care, CHIREC Hospitals, Université Libre de Bruxelles , Brussels , Belgium
| | - Luciano Gattinoni
- Department of Anesthesia and Intensive Care, Georg-August-Universität, Göttingen , Germany
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University , Syracuse, New York
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine , Baltimore, Maryland
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Hasan D, Blankman P, Nieman GF. Purinergic signalling links mechanical breath profile and alveolar mechanics with the pro-inflammatory innate immune response causing ventilation-induced lung injury. Purinergic Signal 2017; 13:363-386. [PMID: 28547381 PMCID: PMC5563293 DOI: 10.1007/s11302-017-9564-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/26/2017] [Indexed: 02/06/2023] Open
Abstract
Severe pulmonary infection or vigorous cyclic deformation of the alveolar epithelial type I (AT I) cells by mechanical ventilation leads to massive extracellular ATP release. High levels of extracellular ATP saturate the ATP hydrolysis enzymes CD39 and CD73 resulting in persistent high ATP levels despite the conversion to adenosine. Above a certain level, extracellular ATP molecules act as danger-associated molecular patterns (DAMPs) and activate the pro-inflammatory response of the innate immunity through purinergic receptors on the surface of the immune cells. This results in lung tissue inflammation, capillary leakage, interstitial and alveolar oedema and lung injury reducing the production of surfactant by the damaged AT II cells and deactivating the surfactant function by the concomitant extravasated serum proteins through capillary leakage followed by a substantial increase in alveolar surface tension and alveolar collapse. The resulting inhomogeneous ventilation of the lungs is an important mechanism in the development of ventilation-induced lung injury. The high levels of extracellular ATP and the upregulation of ecto-enzymes and soluble enzymes that hydrolyse ATP to adenosine (CD39 and CD73) increase the extracellular adenosine levels that inhibit the innate and adaptive immune responses rendering the host susceptible to infection by invading microorganisms. Moreover, high levels of extracellular adenosine increase the expression, the production and the activation of pro-fibrotic proteins (such as TGF-β, α-SMA, etc.) followed by the establishment of lung fibrosis.
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Affiliation(s)
- Djo Hasan
- Department of Adult ICU, University Hospital Erasmus MC Rotterdam, 's-Gravendijkwal 230 3015 CE, Rotterdam, the Netherlands.
| | - Paul Blankman
- Department of Adult ICU, University Hospital Erasmus MC Rotterdam, 's-Gravendijkwal 230 3015 CE, Rotterdam, the Netherlands
| | - Gary F Nieman
- Department of Surgery, Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
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35
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Nieman GF, Satalin J, Kollisch-Singule M, Andrews P, Aiash H, Habashi NM, Gatto LA. Physiology in Medicine: Understanding dynamic alveolar physiology to minimize ventilator-induced lung injury. J Appl Physiol (1985) 2017; 122:1516-1522. [PMID: 28385915 PMCID: PMC7203565 DOI: 10.1152/japplphysiol.00123.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/16/2017] [Accepted: 04/03/2017] [Indexed: 02/01/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) remains a serious clinical problem with the main treatment being supportive in the form of mechanical ventilation. However, mechanical ventilation can be a double-edged sword: if set improperly, it can exacerbate the tissue damage caused by ARDS; this is known as ventilator-induced lung injury (VILI). To minimize VILI, we must understand the pathophysiologic mechanisms of tissue damage at the alveolar level. In this Physiology in Medicine paper, the dynamic physiology of alveolar inflation and deflation during mechanical ventilation will be reviewed. In addition, the pathophysiologic mechanisms of VILI will be reviewed, and this knowledge will be used to suggest an optimal mechanical breath profile (MBP: all airway pressures, volumes, flows, rates, and the duration that they are applied at both inspiration and expiration) necessary to minimize VILI. Our review suggests that the current protective ventilation strategy, known as the “open lung strategy,” would be the optimal lung-protective approach. However, the viscoelastic behavior of dynamic alveolar inflation and deflation has not yet been incorporated into protective mechanical ventilation strategies. Using our knowledge of dynamic alveolar mechanics (i.e., the dynamic change in alveolar and alveolar duct size and shape during tidal ventilation) to modify the MBP so as to minimize VILI will reduce the morbidity and mortality associated with ARDS.
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Affiliation(s)
- Gary F Nieman
- State University of New York Upstate Medical University, Syracuse, New York
| | - Josh Satalin
- State University of New York Upstate Medical University, Syracuse, New York;
| | | | - Penny Andrews
- R Adams Cowley Shock Trauma Center, Baltimore, Maryland
| | - Hani Aiash
- State University of New York Upstate Medical University, Syracuse, New York.,Suez Canal University, Ismailia, Egypt; and
| | | | - Louis A Gatto
- State University of New York Upstate Medical University, Syracuse, New York.,State University of New York Cortland, Cortland, New York
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36
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Nieman GF, Satalin J, Andrews P, Aiash H, Habashi NM, Gatto LA. Personalizing mechanical ventilation according to physiologic parameters to stabilize alveoli and minimize ventilator induced lung injury (VILI). Intensive Care Med Exp 2017; 5:8. [PMID: 28150228 PMCID: PMC5289131 DOI: 10.1186/s40635-017-0121-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/26/2017] [Indexed: 12/15/2022] Open
Abstract
It has been shown that mechanical ventilation in patients with, or at high-risk for, the development of acute respiratory distress syndrome (ARDS) can be a double-edged sword. If the mechanical breath is improperly set, it can amplify the lung injury associated with ARDS, causing a secondary ventilator-induced lung injury (VILI). Conversely, the mechanical breath can be adjusted to minimize VILI, which can reduce ARDS mortality. The current standard of care ventilation strategy to minimize VILI attempts to reduce alveolar over-distension and recruitment-derecruitment (R/D) by lowering tidal volume (Vt) to 6 cc/kg combined with adjusting positive-end expiratory pressure (PEEP) based on a sliding scale directed by changes in oxygenation. Thus, Vt is often but not always set as a “one-size-fits-all” approach and although PEEP is often set arbitrarily at 5 cmH2O, it may be personalized according to changes in a physiologic parameter, most often to oxygenation. However, there is evidence that oxygenation as a method to optimize PEEP is not congruent with the PEEP levels necessary to maintain an open and stable lung. Thus, optimal PEEP might not be personalized to the lung pathology of an individual patient using oxygenation as the physiologic feedback system. Multiple methods of personalizing PEEP have been tested and include dead space, lung compliance, lung stress and strain, ventilation patterns using computed tomography (CT) or electrical impedance tomography (EIT), inflection points on the pressure/volume curve (P/V), and the slope of the expiratory flow curve using airway pressure release ventilation (APRV). Although many studies have shown that personalizing PEEP is possible, there is no consensus as to the optimal technique. This review will assess various methods used to personalize PEEP, directed by physiologic parameters, necessary to adaptively adjust ventilator settings with progressive changes in lung pathophysiology.
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Affiliation(s)
- Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA. .,Cardiopulmonary Critical Care Lab, Department of Surgery, Upstate Medical University, 750 East Adams Street, Syracuse, NY, 13210, USA.
| | | | - Hani Aiash
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, MD, USA
| | - Louis A Gatto
- Biological Sciences Department, Biological Sciences Department, SUNY Cortland, Cortland, NY, USA
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37
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Kollisch-Singule M, Jain SV, Satalin J, Andrews P, Searles Q, Liu Z, Zhou Y, Wang G, Meier AH, Gatto LA, Nieman GF, Habashi NM. Limiting ventilator-associated lung injury in a preterm porcine neonatal model. J Pediatr Surg 2017; 52:50-55. [PMID: 27837992 DOI: 10.1016/j.jpedsurg.2016.10.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/20/2016] [Indexed: 01/28/2023]
Abstract
PURPOSE Preterm infants are prone to respiratory distress syndrome (RDS), with severe cases requiring mechanical ventilation for support. However, there are no clear guidelines regarding the optimal ventilation strategy. We hypothesized that airway pressure release ventilation (APRV) would mitigate lung injury in a preterm porcine neonatal model. METHODS Preterm piglets were delivered on gestational day 98 (85% of 115day term), instrumented, and randomized to volume guarantee (VG; n=10) with low tidal volumes (5.5cm3kg-1) and PEEP 4cmH2O or APRV (n=10) with initial ventilator settings: PHigh 18cmH2O, PLow 0cmH2O, THigh 1.30s, TLow 0.15s. Ventilator setting changes were made in response to clinical parameters in both groups. Animals were monitored continuously for 24hours. RESULTS The mortality rates between the two groups were not significantly different (p>0.05). The VG group had relatively increased oxygen requirements (FiO2 50%±9%) compared with the APRV group (FiO2 28%±5%; p>0.05) and a decrease in PaO2/FiO2 ratio (VG 162±33mmHg; APRV 251±45mmHg; p<0.05). The compliance of the VG group (0.51±0.07L·cmH2O-1) was significantly less than the APRV group (0.90±0.06L·cmH2O-1; p<0.05). CONCLUSION This study demonstrates that APRV improves oxygenation and compliance as compared with VG. This preliminary work suggests further study into the clinical uses of APRV in the neonate is warranted. LEVEL OF EVIDENCE Not Applicable (Basic Science Animal Study).
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Affiliation(s)
| | - Sumeet V Jain
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD, 21201, USA.
| | - Quinn Searles
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Zhiyong Liu
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Yan Zhou
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Guirong Wang
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Andreas H Meier
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA; Department of Biological Sciences, SUNY Cortland, 22 Graham Ave, Cortland, NY, 13045, USA.
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY, 13210, USA.
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD, 21201, USA.
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Habashi NM, Andrews P, Nieman GF, Kollisch-Singule M, Bates JHT. Failure to Disclose Conflicts of Interest. JAMA Surg 2016; 151:1190. [PMID: 27602556 DOI: 10.1001/jamasurg.2016.3003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Nader M Habashi
- University of Maryland Medical Center, Baltimore2Intensive Care On-line Network (ICON), Baltimore, Maryland
| | - Penny Andrews
- University of Maryland Medical Center, Baltimore2Intensive Care On-line Network (ICON), Baltimore, Maryland
| | - Gary F Nieman
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
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39
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Tao JQ, Sorokina EM, Vazquez Medina JP, Mishra MK, Yamada Y, Satalin J, Nieman GF, Nellen JR, Beduhn B, Cantu E, Habashi NM, Jungraithmayr W, Christie JD, Chatterjee S. Onset of Inflammation With Ischemia: Implications for Donor Lung Preservation and Transplant Survival. Am J Transplant 2016; 16:2598-611. [PMID: 26998598 DOI: 10.1111/ajt.13794] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 02/16/2016] [Accepted: 03/08/2016] [Indexed: 01/25/2023]
Abstract
Lungs stored ahead of transplant surgery experience ischemia. Pulmonary ischemia differs from ischemia in the systemic organs in that stop of blood flow in the lung leads to loss of shear alone because the lung parenchyma does not rely on blood flow for its cellular oxygen requirements. Our earlier studies on the ischemia-induced mechanosignaling cascade showed that the pulmonary endothelium responds to stop of flow by production of reactive oxygen species (ROS). We hypothesized that ROS produced in this way led to induction of proinflammatory mediators. In this study, we used lungs or cells subjected to various periods of storage and evaluated the induction of several proinflammatory mediators. Isolated murine, porcine and human lungs in situ showed increased expression of cellular adhesion molecules; the damage-associated molecular pattern protein high-mobility group box 1 and the corresponding pattern recognition receptor, called the receptor for advanced glycation end products; and induction stabilization and translocation of hypoxia-inducible factor 1α and its downstream effector VEGFA, all of which are participants in inflammation. We concluded that signaling with lung preservation drives expression of inflammatory mediators that potentially predispose the donor lung to an inflammatory response after transplant.
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Affiliation(s)
- J-Q Tao
- Institute for Environmental Medicine and Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - E M Sorokina
- Institute for Environmental Medicine and Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - J P Vazquez Medina
- Institute for Environmental Medicine and Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - M K Mishra
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania School of Medicine, Philadelphia, PA
| | - Y Yamada
- Division of Thoracic Surgery, University Hospital Zurich, Zurich, Switzerland
| | - J Satalin
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - G F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY
| | - J R Nellen
- Cardiovascular Surgery Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - B Beduhn
- Cardiovascular Surgery Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - E Cantu
- Cardiovascular Surgery Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - N M Habashi
- Surgical Critical Care, University of Maryland Medical Center, Baltimore, MD
| | - W Jungraithmayr
- Division of Thoracic Surgery, University Hospital Zurich, Zurich, Switzerland
| | - J D Christie
- Cardiovascular Surgery Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.,Pulmonary Allergy and Critical Care Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - S Chatterjee
- Institute for Environmental Medicine and Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
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40
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Nieman GF, Satalin J, Andrews P, Habashi NM, Gatto LA. Lung stress, strain, and energy load: engineering concepts to understand the mechanism of ventilator-induced lung injury (VILI). Intensive Care Med Exp 2016; 4:16. [PMID: 27316442 PMCID: PMC4912503 DOI: 10.1186/s40635-016-0090-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/08/2016] [Indexed: 01/15/2023] Open
Abstract
It was recently shown that acute respiratory distress syndrome (ARDS) mortality has not been reduced in over 15 years and remains ~40 %, even with protective low tidal volume (LVt) ventilation. Thus, there is a critical need to develop novel ventilation strategies that will protect the lung and reduce ARDS mortality. Protti et al. have begun to analyze the impact of mechanical ventilation on lung tissue using engineering methods in normal pigs ventilated for 54 h. They used these methods to assess the impact of a mechanical breath on dynamic and static global lung strain and energy load. Strain is the change in lung volume in response to an applied stress (i.e., Tidal Volume-Vt). This study has yielded a number of exciting new concepts including the following: (1) Individual mechanical breath parameters (e.g., Vt or Plateau Pressure) are not directly correlated with VILI but rather any combination of parameters that subject the lung to excessive dynamic strain and energy/power load will cause VILI; (2) all strain is not equal; dynamic strain resulting in a dynamic energy load (i.e., kinetic energy) is more damaging to lung tissue than static strain and energy load (i.e., potential energy); and (3) a critical consideration is not just the size of the Vt but the size of the lung that is being ventilated by this Vt. This key concept merits attention since our current protective ventilation strategies are fixated on the priority of keeping the Vt low. If the lung is fully inflated, a large Vt is not necessarily injurious. In conclusion, using engineering concepts to analyze the impact of the mechanical breath on the lung is a novel new approach to investigate VILI mechanisms and to help design the optimally protective breath. Data generated using these methods have challenged some of the current dogma surrounding the mechanisms of VILI and of the components in the mechanical breath necessary for lung protection.
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Affiliation(s)
- Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA
| | - Louis A Gatto
- Biology Department, SUNY Cortland, Cortland, NY, USA
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41
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Kollisch-Singule M, Jain S, Andrews P, Smith BJ, Hamlington-Smith KL, Roy S, DiStefano D, Nuss E, Satalin J, Meng Q, Marx W, Bates JHT, Gatto LA, Nieman GF, Habashi NM. Effect of Airway Pressure Release Ventilation on Dynamic Alveolar Heterogeneity. JAMA Surg 2016; 151:64-72. [PMID: 26444302 DOI: 10.1001/jamasurg.2015.2683] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Ventilator-induced lung injury may arise from heterogeneous lung microanatomy, whereby some alveoli remain collapsed throughout the breath cycle while their more compliant or surfactant-replete neighbors become overdistended, and this is called dynamic alveolar heterogeneity. OBJECTIVE To determine how dynamic alveolar heterogeneity is influenced by 2 modes of mechanical ventilation: low tidal-volume ventilation (LTVV) and airway pressure release ventilation (APRV), using in vivo microscopy to directly measure alveolar size distributions. DESIGN, SETTING, AND PARTICIPANTS In a randomized, nonblinded laboratory animal study conducted between January 2013 and December 2014, 14 rats (450-500 g in size) were randomized to a control group with uninjured lungs (n = 4) and 2 experimental groups with surfactant deactivation induced by polysorbate lavage: the LTVV group (n = 5) and the APRV group (n = 5). For all groups, a thoracotomy and in vivo microscopy were performed. Following lung injury induced by polysorbate lavage, the LTVV group was ventilated with a tidal volume of 6 mL/kg and progressively higher positive end-expiratory pressure (PEEP) (5, 10, 16, 20, and 24 cm H2O). Following lung injury induced by polysorbate lavage, the APRV group was ventilated with a progressively shorter time at low pressure, which increased the ratio of the end-expiratory flow rate (EEFR) to the peak expiratory flow rate (PEFR; from 10% to 25% to 50% to 75%). MAIN OUTCOMES AND MEASURES Alveolar areas were quantified (using PEEP and EEFR to PEFR ratio) to determine dynamic heterogeneity. RESULTS Following lung injury induced by polysorbate lavage, a higher PEEP (20-24 cm H2O) with LTVV resulted in alveolar occupancy (reported as percentage of total frame area) at inspiration (39.9%-42.2%) and expiration (35.9%-38.7%) similar to that in the control group (inspiration 53.3%; expiration 50.3%; P > .01). Likewise, APRV with an increased EEFR to PEFR ratio (50%-75%) resulted in alveolar occupancy at inspiration (46.7%-47.9%) and expiration (40.2%-46.6%) similar to that in the control group (P > .01). At inspiration, the distribution of the alveolar area of the control group was similar to that of the APRV group (P > .01) (but not to that of the LTVV group [P < .01]). A lower PEEP (5-10 cm H2O) and a decreased EEFR to PEFR ratio (≤50%) demonstrated dynamic heterogeneity between inspiration and expiration (P < .01 for both) with a greater percentage of large alveoli at expiration. Dynamic alveolar homogeneity between inspiration and expiration occurred with higher PEEP (16-24 cm H2O) (P > .01) and an increased EEFR to PEFR ratio (75%) (P > .01). CONCLUSIONS AND RELEVANCE Increasing PEEP during LTVV increased alveolar recruitment and dynamic homogeneity but had a significantly different alveolar size distribution compared with the control group. By comparison, reducing the time at low pressure (EEFR to PEFR ratio of 75%) in the APRV group provided dynamic homogeneity and a closer approximation of the dynamics observed in the control group.
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Affiliation(s)
| | - Sumeet Jain
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore
| | | | | | - Shreyas Roy
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - David DiStefano
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - Emily Nuss
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - Josh Satalin
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - Qinghe Meng
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - William Marx
- Department of Surgery, State University of New York Upstate Medical University, Syracuse4Syracuse Veterans Affairs Medical Center, Syracuse, New York
| | | | - Louis A Gatto
- Department of Surgery, State University of New York Upstate Medical University, Syracuse5Department of Biological Sciences, State University of New York at Cortland, Cortland
| | - Gary F Nieman
- Department of Surgery, State University of New York Upstate Medical University, Syracuse
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore
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Jain SV, Kollisch-Singule M, Sadowitz B, Dombert L, Satalin J, Andrews P, Gatto LA, Nieman GF, Habashi NM. The 30-year evolution of airway pressure release ventilation (APRV). Intensive Care Med Exp 2016; 4:11. [PMID: 27207149 PMCID: PMC4875584 DOI: 10.1186/s40635-016-0085-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/03/2016] [Indexed: 02/07/2023] Open
Abstract
Airway pressure release ventilation (APRV) was first described in 1987 and defined as continuous positive airway pressure (CPAP) with a brief release while allowing the patient to spontaneously breathe throughout the respiratory cycle. The current understanding of the optimal strategy to minimize ventilator-induced lung injury is to "open the lung and keep it open". APRV should be ideal for this strategy with the prolonged CPAP duration recruiting the lung and the minimal release duration preventing lung collapse. However, APRV is inconsistently defined with significant variation in the settings used in experimental studies and in clinical practice. The goal of this review was to analyze the published literature and determine APRV efficacy as a lung-protective strategy. We reviewed all original articles in which the authors stated that APRV was used. The primary analysis was to correlate APRV settings with physiologic and clinical outcomes. Results showed that there was tremendous variation in settings that were all defined as APRV, particularly CPAP and release phase duration and the parameters used to guide these settings. Thus, it was impossible to assess efficacy of a single strategy since almost none of the APRV settings were identical. Therefore, we divided all APRV studies divided into two basic categories: (1) fixed-setting APRV (F-APRV) in which the release phase is set and left constant; and (2) personalized-APRV (P-APRV) in which the release phase is set based on changes in lung mechanics using the slope of the expiratory flow curve. Results showed that in no study was there a statistically significant worse outcome with APRV, regardless of the settings (F-ARPV or P-APRV). Multiple studies demonstrated that P-APRV stabilizes alveoli and reduces the incidence of acute respiratory distress syndrome (ARDS) in clinically relevant animal models and in trauma patients. In conclusion, over the 30 years since the mode's inception there have been no strict criteria in defining a mechanical breath as being APRV. P-APRV has shown great promise as a highly lung-protective ventilation strategy.
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Affiliation(s)
- Sumeet V Jain
- Department of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | | | - Benjamin Sadowitz
- Department of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Luke Dombert
- Department of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Josh Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA.
| | - Penny Andrews
- Multi-trauma Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, 22 South Greene Street, Baltimore, MD, USA
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA.,Department of Biological Sciences, 10 SUNY Cortland, Cortland, NY, 13045, USA
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY, 13210, USA
| | - Nader M Habashi
- Multi-trauma Critical Care, R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, 22 South Greene Street, Baltimore, MD, USA
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Satalin J, Andrews P, Gatto LA, Habashi NM, Nieman GF. "Open the lung and keep it open": a homogeneously ventilated lung is a 'healthy lung'. Ann Transl Med 2016; 4:141. [PMID: 27162791 DOI: 10.21037/atm.2016.03.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Joshua Satalin
- 1 Department of Surgery, Upstate Medical University, Syracuse, NY, USA ; 2 Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA ; 3 Biological Sciences Department, SUNY Cortland, Cortland, NY, USA
| | - Penny Andrews
- 1 Department of Surgery, Upstate Medical University, Syracuse, NY, USA ; 2 Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA ; 3 Biological Sciences Department, SUNY Cortland, Cortland, NY, USA
| | - Louis A Gatto
- 1 Department of Surgery, Upstate Medical University, Syracuse, NY, USA ; 2 Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA ; 3 Biological Sciences Department, SUNY Cortland, Cortland, NY, USA
| | - Nader M Habashi
- 1 Department of Surgery, Upstate Medical University, Syracuse, NY, USA ; 2 Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA ; 3 Biological Sciences Department, SUNY Cortland, Cortland, NY, USA
| | - Gary F Nieman
- 1 Department of Surgery, Upstate Medical University, Syracuse, NY, USA ; 2 Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA ; 3 Biological Sciences Department, SUNY Cortland, Cortland, NY, USA
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Abstract
Trauma, hemorrhagic shock, or sepsis can incite systemic inflammatory response syndrome, which can result in early acute lung injury (EALI). As EALI advances, improperly set mechanical ventilation (MV) can amplify early injury into a secondary ventilator-induced lung injury that invariably develops into overt ARDS. Once established, ARDS is refractory to most therapeutic strategies, which have not been able to lower ARDS mortality below the current unacceptably high 40%. Low tidal volume ventilation is one of the few treatments shown to have a moderate positive impact on ARDS survival, presumably by reducing ventilator-induced lung injury. Thus, there is a compelling case to be made that the focus of ARDS management should switch from treatment once this syndrome has become established to the application of preventative measures while patients are still in the EALI stage. Indeed, studies have shown that ARDS incidence is markedly reduced when conventional MV is applied preemptively using a combination of low tidal volume and positive end-expiratory pressure in both patients in the ICU and in surgical patients at high risk for developing ARDS. Furthermore, there is evidence from animal models and high-risk trauma patients that superior prevention of ARDS can be achieved using preemptive airway pressure release ventilation with a very brief duration of pressure release. Preventing rather than treating ARDS may be the way forward in dealing with this recalcitrant condition and would represent a paradigm shift in the way that MV is currently practiced.
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Affiliation(s)
- Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, NY.
| | | | | | - Nader M Habashi
- R Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, MD
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Kollisch-Singule M, Emr B, Jain SV, Andrews P, Satalin J, Liu J, Porcellio E, Kenyon V, Wang G, Marx W, Gatto LA, Nieman GF, Habashi NM. The effects of airway pressure release ventilation on respiratory mechanics in extrapulmonary lung injury. Intensive Care Med Exp 2015; 3:35. [PMID: 26694915 PMCID: PMC4688284 DOI: 10.1186/s40635-015-0071-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/13/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Lung injury is often studied without consideration for pathologic changes in the chest wall. In order to reduce the incidence of lung injury using preemptive mechanical ventilation, it is important to recognize the influence of altered chest wall mechanics on disease pathogenesis. In this study, we hypothesize that airway pressure release ventilation (APRV) may be able to reduce the chest wall elastance associated with an extrapulmonary lung injury model as compared with low tidal volume (LVt) ventilation. METHODS Female Yorkshire pigs were anesthetized and instrumented. Fecal peritonitis was established, and the superior mesenteric artery was clamped for 30 min to induce an ischemia/reperfusion injury. Immediately following injury, pigs were randomized into (1) LVt (n = 3), positive end-expiratory pressure (PEEP) 5 cmH2O, V t 6 cc kg(-1), FiO2 21 %, and guided by the ARDSnet protocol or (2) APRV (n = 3), P High 16-22 cmH2O, P Low 0 cmH2O, T High 4.5 s, T Low set to terminate the peak expiratory flow at 75 %, and FiO2 21 %. Pigs were monitored continuously for 48 h. Lung samples and bronchoalveolar lavage fluid were collected at necropsy. RESULTS LVt resulted in mild acute respiratory distress syndrome (ARDS) (PaO2/FiO2 = 226.2 ± 17.1 mmHg) whereas APRV prevented ARDS (PaO2/FiO2 = 465.7 ± 66.5 mmHg; p < 0.05). LVt had a reduced surfactant protein A concentration and increased histologic injury as compared with APRV. The plateau pressure in APRV (34.3 ± 0.9 cmH2O) was significantly greater than LVt (22.2 ± 2.0 cmH2O; p < 0.05) yet transpulmonary pressure between groups was similar (p > 0.05). This was because the pleural pressure was significantly lower in LVt (7.6 ± 0.5 cmH2O) as compared with APRV (17.4 ± 3.5 cmH2O; p < 0.05). Finally, the elastance of the lung, chest wall, and respiratory system were all significantly greater in LVt as compared with APRV (all p < 0.05). CONCLUSIONS APRV preserved surfactant and lung architecture and maintenance of oxygenation. Despite the greater plateau pressure and tidal volumes in the APRV group, the transpulmonary pressure was similar to that of LVt. Thus, the majority of the plateau pressure in the APRV group was distributed as pleural pressure in this extrapulmonary lung injury model. APRV maintained a normal lung elastance and an open, homogeneously ventilated lung without increasing lung stress.
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Affiliation(s)
- Michaela Kollisch-Singule
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Bryanna Emr
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Sumeet V Jain
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Penny Andrews
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Jiao Liu
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Elizabeth Porcellio
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Van Kenyon
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Guirong Wang
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - William Marx
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA. .,Department of Biological Sciences, SUNY Cortland, Cortland, NY, USA.
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY, 13210, USA.
| | - Nader M Habashi
- Department of Trauma Critical Care Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, USA.
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46
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Nieman GF, Gatto LA, Habashi NM. Reducing acute respiratory distress syndrome occurrence using mechanical ventilation. World J Respirol 2015; 5:188-198. [DOI: 10.5320/wjr.v5.i3.188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 07/01/2015] [Accepted: 07/17/2015] [Indexed: 02/06/2023] Open
Abstract
The standard treatment for acute respiratory distress syndrome (ARDS) is supportive in the form of low tidal volume ventilation applied after significant lung injury has already developed. Nevertheless, ARDS mortality remains unacceptably high (> 40%). Indeed, once ARDS is established it becomes refractory to treatment, and therefore avoidance is key. However, preventive techniques and therapeutics to reduce the incidence of ARDS in patients at high-risk have not been validated clinically. This review discusses the current data suggesting that preemptive application of the properly adjusted mechanical breath can block progressive acute lung injury and significantly reduce the occurrence of ARDS.
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Nieman GF, Gatto LA, Habashi NM. Impact of mechanical ventilation on the pathophysiology of progressive acute lung injury. J Appl Physiol (1985) 2015; 119:1245-61. [PMID: 26472873 DOI: 10.1152/japplphysiol.00659.2015] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/01/2015] [Indexed: 02/08/2023] Open
Abstract
The earliest description of what is now known as the acute respiratory distress syndrome (ARDS) was a highly lethal double pneumonia. Ashbaugh and colleagues (Ashbaugh DG, Bigelow DB, Petty TL, Levine BE Lancet 2: 319-323, 1967) correctly identified the disease as ARDS in 1967. Their initial study showing the positive effect of mechanical ventilation with positive end-expiratory pressure (PEEP) on ARDS mortality was dampened when it was discovered that improperly used mechanical ventilation can cause a secondary ventilator-induced lung injury (VILI), thereby greatly exacerbating ARDS mortality. This Synthesis Report will review the pathophysiology of ARDS and VILI from a mechanical stress-strain perspective. Although inflammation is also an important component of VILI pathology, it is secondary to the mechanical damage caused by excessive strain. The mechanical breath will be deconstructed to show that multiple parameters that comprise the breath-airway pressure, flows, volumes, and the duration during which they are applied to each breath-are critical to lung injury and protection. Specifically, the mechanisms by which a properly set mechanical breath can reduce the development of excessive fluid flux and pulmonary edema, which are a hallmark of ARDS pathology, are reviewed. Using our knowledge of how multiple parameters in the mechanical breath affect lung physiology, the optimal combination of pressures, volumes, flows, and durations that should offer maximum lung protection are postulated.
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Affiliation(s)
- Gary F Nieman
- Department of Surgery, Upstate Medical University, Syracuse, New York;
| | - Louis A Gatto
- Biological Sciences Department, State University of New York, Cortland, New York; and
| | - Nader M Habashi
- R Adams Cowley Shock/Trauma Center, University of Maryland Medical Center, Baltimore, Maryland
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48
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Emr BM, Roy S, Kollisch-Singule M, Gatto LA, Barravecchia M, Lin X, Young JL, Wang G, Liu J, Satalin J, Snyder K, Nieman GF, Dean DA. Electroporation-mediated gene delivery of Na+,K+ -ATPase, and ENaC subunits to the lung attenuates acute respiratory distress syndrome in a two-hit porcine model. Shock 2015; 43:16-23. [PMID: 25004064 DOI: 10.1097/shk.0000000000000228] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Acute respiratory distress syndrome (ARDS) is a common cause of organ failure with an associated mortality rate of 40%. The initiating event is disruption of alveolar-capillary interface causing leakage of edema into alveoli. HYPOTHESIS Electroporation-mediated gene delivery of epithelial sodium channel (ENaC) and Na+,K+ -ATPase into alveolar cells would improve alveolar clearance of edema and attenuate ARDS. METHODS Pigs were anesthetized and instrumented, and the superior mesenteric artery was clamped to cause gut ischemia/reperfusion injury and peritoneal sepsis by fecal clot implantation. Animals were ventilated according to ARDSnet protocol. Four hours after injury, animals were randomized into groups: (i) treatment: Na+,K+ -ATPase/ENaC plasmid (n = 5) and (ii) control: empty plasmid (n = 5). Plasmids were delivered to the lung using bronchoscope. Electroporation was delivered using eight-square-wave electric pulses across the chest. Following electroporation, pigs were monitored 48 h. RESULTS The Pao2/Fio2 ratio and lung compliance were higher in the treatment group. Lung wet/dry ratio was lower in the treatment group. Relative expression of the Na+,K+ -ATPase transgene was higher throughout lungs receiving treatment plasmids. Quantitative histopathology revealed a reduction in intra-alveolar fibrin in the treatment group. Bronchoalveolar lavage showed increased surfactant protein B in the treatment group. Survival was improved in the treatment group. CONCLUSIONS Electroporation-mediated transfer of Na+,K+ -ATPase/ENaC plasmids improved lung function, reduced fibrin deposits, decreased lung edema, and improved survival in a translational porcine model of ARDS. Gene therapy can attenuate ARDS pathophysiology in a high-fidelity animal model, suggesting a potential new therapy for patients.
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Affiliation(s)
- Bryanna M Emr
- *Department of Surgery, SUNY Upstate Medical University, Syracuse; †Department of Biology, SUNY Cortland, Cortland; and Departments of ‡Pediatrics and §Biomedical Engineering, University of Rochester, Rochester, New York
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Andrews PL, Sadowitz B, Kollisch-Singule M, Satalin J, Roy S, Snyder K, Gatto LA, Nieman GF, Habashi NM. Alveolar instability (atelectrauma) is not identified by arterial oxygenation predisposing the development of an occult ventilator-induced lung injury. Intensive Care Med Exp 2015. [PMID: 26215818 PMCID: PMC4480795 DOI: 10.1186/s40635-015-0054-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Improperly set mechanical ventilation (MV) with normal lungs can advance lung injury and increase the incidence of acute respiratory distress syndrome (ARDS). A key mechanism of ventilator-induced lung injury (VILI) is an alteration in alveolar mechanics including alveolar instability or recruitment/derecruitment (R/D). We hypothesize that R/D cannot be identified by PaO2 (masking occult VILI), and if protective ventilation is not applied, ARDS incidence will increase. METHODS Sprague-Dawley rats (n = 8) were anesthetized, surgically instrumented, and placed on MV. A thoracotomy was performed and an in vivo microscope attached to the pleural surface of the lung with baseline dynamic changes in alveolar size during MV recorded. Alveolar instability was induced by intra-tracheal instillation of Tween and alveolar R/D identified as a marked change in alveolar size from inspiration to expiration with increases in positive end-expiratory pressure (PEEP) levels. RESULTS Despite maintaining a clinically acceptable PaO2 (55-80 mmHg), the alveoli remained unstable with significant R/D at low PEEP levels. Although PaO2 consistently increased with an increase in PEEP, R/D did not plateau until PEEP was >9 cmH2O. CONCLUSIONS PaO2 remained clinically acceptable while alveolar instability persisted at all levels of PEEP (especially PEEP <9 cmH2O). Therefore, PaO2 levels cannot be used reliably to guide protective MV strategies or infer that VILI is not occurring. Using PaO2 to set a PEEP level necessary to stabilize the alveoli could underestimate the potential for VILI. These findings highlight the need for more accurate marker(s) of alveolar stability to guide protective MV necessary to prevent VILI.
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Affiliation(s)
- Penny L Andrews
- Department of Critical Care, R Adams Cowley Shock Trauma Center, Baltimore, MD, USA,
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50
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Chatterjee S, Nieman GF, Christie JD, Fisher AB. Response to letter by Dr. M. S. A. Mohamed (Antagonizing reactive oxygen species during lung perfusion). Am J Physiol Lung Cell Mol Physiol 2015; 307:L909. [PMID: 25447221 DOI: 10.1152/ajplung.00310.2014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Shampa Chatterjee
- Institute for Environmental Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania;
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York; and
| | - Jason D Christie
- Pulmonary Allergy and Critical Care Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Aron B Fisher
- Institute for Environmental Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
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