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Bates JHT, Kaczka DW, Kollisch-Singule M, Nieman GF, Gaver DP. Atelectrauma can be avoided if expiration is sufficiently brief: evidence from inverse modeling and oscillometry during airway pressure release ventilation. Crit Care 2024; 28:329. [PMID: 39380082 PMCID: PMC11462759 DOI: 10.1186/s13054-024-05112-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2024] [Accepted: 09/29/2024] [Indexed: 10/10/2024] Open
Abstract
BACKGROUND Airway pressure release ventilation (APRV) has been shown to be protective against atelectrauma if expirations are brief. We hypothesize that this is protective because epithelial surfaces are not given enough time to come together and adhere during expiration, thereby avoiding their highly damaging forced separation during inspiration. METHODS We investigated this hypothesis in a porcine model of ARDS induced by Tween lavage. Animals were ventilated with APRV in 4 groups based on whether inspiratory pressure was 28 or 40 cmH2O, and whether expiration was terminated when end-expiratory flow reached either 75% (a shorter expiration) or 25% (a longer expiration) of its initial peak value. A mathematical model of respiratory system mechanics that included a volume-dependent elastance term characterized by the parameter E 2 was fit to airway pressure-flow data obtained each hour for 6 h post-Tween injury during both expiration and inspiration. We also measured respiratory system impedance between 5 and 19 Hz continuously through inspiration at the same time points from which we derived a time-course for respiratory system resistance ( R rs ). RESULTS E 2 during both expiration and inspiration was significantly different between the two longer expiration versus the two shorter expiration groups (ANOVA, p < 0.001). We found that E 2 was most depressed during inspiration in the higher-pressure group receiving the longer expiration, suggesting that E 2 reflects a balance between strain stiffening of the lung parenchyma and ongoing recruitment as lung volume increases. We also found in this group that R rs increased progressively during the first 0.5 s of inspiration and then began to decrease again as inspiration continued, which we interpret as corresponding to the point when continuing derecruitment was reversed by progressive lung inflation. CONCLUSIONS These findings support the hypothesis that sufficiently short expiratory durations protect against atelectrauma because they do not give derecruitment enough time to manifest. This suggests a means for the personalized adjustment of mechanical ventilation.
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Affiliation(s)
- Jason H T Bates
- Department of Medicine, University of Vermont, University of Vermont Larner College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA.
| | - David W Kaczka
- Departments of Anesthesia, Biomedical Engineering, and Radiology, University of Iowa, Iowa City, IA, 52242, USA
| | | | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical Center, Syracuse, NY, 13210, USA
| | - Donald P Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
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2
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Zhou Y, Cheng J, Zhu S, Dong M, Lv Y, Jing X, Kang Y. Early pathophysiology-driven airway pressure release ventilation versus low tidal volume ventilation strategy for patients with moderate-severe ARDS: study protocol for a randomized, multicenter, controlled trial. BMC Pulm Med 2024; 24:252. [PMID: 38783268 PMCID: PMC11112826 DOI: 10.1186/s12890-024-03065-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Conventional Mechanical ventilation modes used for individuals suffering from acute respiratory distress syndrome have the potential to exacerbate lung injury through regional alveolar overinflation and/or repetitive alveolar collapse with shearing, known as atelectrauma. Animal studies have demonstrated that airway pressure release ventilation (APRV) offers distinct advantages over conventional mechanical ventilation modes. However, the methodologies for implementing APRV vary widely, and the findings from clinical studies remain controversial. This study (APRVplus trial), aims to assess the impact of an early pathophysiology-driven APRV ventilation approach compared to a low tidal volume ventilation (LTV) strategy on the prognosis of patients with moderate to severe ARDS. METHODS The APRVplus trial is a prospective, multicenter, randomized clinical trial, building upon our prior single-center study, to enroll 840 patients from at least 35 hospitals in China. This investigation plans to compare the early pathophysiology-driven APRV ventilation approach with the control intervention of LTV lung-protective ventilation. The primary outcome measure will be all-cause mortality at 28 days after randomization in the intensive care units (ICU). Secondary outcome measures will include assessments of oxygenation, and physiology parameters at baseline, as well as on days 1, 2, and 3. Additionally, clinical outcomes such as ventilator-free days at 28 days, duration of ICU and hospital stay, ICU and hospital mortality, and the occurrence of adverse events will be evaluated. TRIAL ETHICS AND DISSEMINATION The research project has obtained approval from the Ethics Committee of West China Hospital of Sichuan University (2019-337). Informed consent is required. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences. TRIAL REGISTRATION The study was registered at Clinical Trials.gov (NCT03549910) on June 8, 2018.
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Affiliation(s)
- Yongfang Zhou
- Department of Respiratory Care, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China.
| | - Jiangli Cheng
- Department of Respiratory Care, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China
| | - Shuo Zhu
- Department of Respiratory Care, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China
| | - Meiling Dong
- Department of Respiratory Care, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China
| | - Yinxia Lv
- Department of Respiratory Care, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China
| | - Xiaorong Jing
- Department of Respiratory Care, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China
| | - Yan Kang
- Department of Critical Care Medicine, West China Hospital of Sichuan University, Guoxue Alley 37#, Wuhou District, Chengdu, Sichuan, 610041, China.
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Geitner CM, Köglmeier LJ, Frerichs I, Langguth P, Lindner M, Schädler D, Weiler N, Becher T, Wall WA. Pressure- and time-dependent alveolar recruitment/derecruitment in a spatially resolved patient-specific computational model for injured human lungs. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3787. [PMID: 38037251 DOI: 10.1002/cnm.3787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/28/2023] [Accepted: 10/16/2023] [Indexed: 12/02/2023]
Abstract
We present a novel computational model for the dynamics of alveolar recruitment/derecruitment (RD), which reproduces the underlying characteristics typically observed in injured lungs. The basic idea is a pressure- and time-dependent variation of the stress-free reference volume in reduced dimensional viscoelastic elements representing the acinar tissue. We choose a variable reference volume triggered by critical opening and closing pressures in a time-dependent manner from a straightforward mechanical point of view. In the case of (partially and progressively) collapsing alveolar structures, the volume available for expansion during breathing reduces and vice versa, eventually enabling consideration of alveolar collapse and reopening in our model. We further introduce a method for patient-specific determination of the underlying critical parameters of the new alveolar RD dynamics when integrated into the tissue elements, referred to as terminal units, of a spatially resolved physics-based lung model that simulates the human respiratory system in an anatomically correct manner. Relevant patient-specific parameters of the terminal units are herein determined based on medical image data and the macromechanical behavior of the lung during artificial ventilation. We test the whole modeling approach for a real-life scenario by applying it to the clinical data of a mechanically ventilated patient. The generated lung model is capable of reproducing clinical measurements such as tidal volume and pleural pressure during various ventilation maneuvers. We conclude that this new model is an important step toward personalized treatment of ARDS patients by considering potentially harmful mechanisms-such as cyclic RD and overdistension-and might help in the development of relevant protective ventilation strategies to reduce ventilator-induced lung injury (VILI).
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Affiliation(s)
- Carolin M Geitner
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
| | - Lea J Köglmeier
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Patrick Langguth
- Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Matthias Lindner
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Dirk Schädler
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Norbert Weiler
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Tobias Becher
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Wolfgang A Wall
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
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4
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Lan L, Ni Y, Zhou Y, Fu L, Wu W, Li P, Yu H, Liang G, Luo F. PEEP-Induced Lung Recruitment Maneuver Combined with Prone Position for ARDS: A Single-Center, Prospective, Randomized Clinical Trial. J Clin Med 2024; 13:853. [PMID: 38337547 PMCID: PMC10856548 DOI: 10.3390/jcm13030853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/28/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
Background: Prone position (PP) and the positive end-expiratory pressure (PEEP)-induced lung recruitment maneuver (LRM) are both efficient in improving oxygenation and prognosis in patients with ARDS. The synergistic effect of PP combined with PEEP-induced LRM in patients with ARDS remains unclear. We aim to explore the effects of PP combined with PEEP-induced LRM on prognosis in patients with moderate to severe ARDS and the predicting role of lung recruitablity. Methods: Patients with moderate to severe ARDS were consecutively enrolled. The patients were prospectively assigned to either the intervention (PP with PEEP-induced LRM) or control groups (PP). The clinical outcomes, respiratory mechanics, and electric impedance tomography (EIT) monitoring results for the two groups were compared. Lung recruitablity (recruitment-to-inflation ratio: R/I) was measured during the PEEP-induced LRM procedure and was used for predicting the response to LRM. Results: Fifty-eight patients were included in the final analysis, among which 28 patients (48.2%) received PEEP-induced LRM combined with PP. PEEP-induced LRM enhanced the effect of PP by a significant improvement in oxygenation (∆PaO2/FiO2 75.8 mmHg vs. 4.75 mmHg, p < 0.001) and the compliance of respiratory system (∆Crs, 2 mL/cmH2O vs. -1 mL/cmH2O, p = 0.02) among ARDS patients. Based on the EIT measurement, PP combined with PEEP-induced LRM increased the ventilation distribution mainly in the dorsal region (5.0% vs. 2.0%, p = 0.015). The R/I ratio was measured in 28 subjects. The higher R/I ratio was related to greater oxygenation improvement after LRM (Pearson's r = 0.4; p = 0.034). Conclusions: In patients with moderate to severe ARDS, PEEP-induced LRM combined with PP can improve oxygenation and dorsal ventilation distribution. R/I can be useful to predict responses to LRM.
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Affiliation(s)
- Lan Lan
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - Yuenan Ni
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - Yubei Zhou
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - Linxi Fu
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - Wentao Wu
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - Ping Li
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - He Yu
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
| | - Guopeng Liang
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
| | - Fengming Luo
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610064, China; (L.L.); (Y.N.); (Y.Z.); (L.F.); (W.W.); (P.L.); (H.Y.); (G.L.)
- State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital, Sichuan University, Chengdu 610064, China
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5
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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] [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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Geitner CM, Becher T, Frerichs I, Weiler N, Bates JHT, Wall WA. An approach to study recruitment/derecruitment dynamics in a patient-specific computational model of an injured human lung. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3745. [PMID: 37403527 DOI: 10.1002/cnm.3745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/04/2023] [Accepted: 06/04/2023] [Indexed: 07/06/2023]
Abstract
We present a new approach for physics-based computational modeling of diseased human lungs. Our main object is the development of a model that takes the novel step of incorporating the dynamics of airway recruitment/derecruitment into an anatomically accurate, spatially resolved model of respiratory system mechanics, and the relation of these dynamics to airway dimensions and the biophysical properties of the lining fluid. The importance of our approach is that it potentially allows for more accurate predictions of where mechanical stress foci arise in the lungs, since it is at these locations that injury is thought to arise and propagate from. We match the model to data from a patient with acute respiratory distress syndrome (ARDS) to demonstrate the potential of the model for revealing the underlying derangements in ARDS in a patient-specific manner. To achieve this, the specific geometry of the lung and its heterogeneous pattern of injury are extracted from medical CT images. The mechanical behavior of the model is tailored to the patient's respiratory mechanics using measured ventilation data. In retrospective simulations of various clinically performed, pressure-driven ventilation profiles, the model adequately reproduces clinical quantities measured in the patient such as tidal volume and change in pleural pressure. The model also exhibits physiologically reasonable lung recruitment dynamics and has the spatial resolution to allow the study of local mechanical quantities such as alveolar strains. This modeling approach advances our ability to perform patient-specific studies in silico, opening the way to personalized therapies that will optimize patient outcomes.
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Affiliation(s)
- Carolin M Geitner
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
| | - Tobias Becher
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Norbert Weiler
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Jason H T Bates
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Wolfgang A Wall
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
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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] [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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8
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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] [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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9
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Severin R, Franz CK, Farr E, Meirelles C, Arena R, Phillips SA, Bond S, Ferraro F, Faghy M. The effects of COVID-19 on respiratory muscle performance: making the case for respiratory muscle testing and training. Eur Respir Rev 2022; 31:31/166/220006. [PMID: 36198415 PMCID: PMC9724806 DOI: 10.1183/16000617.0006-2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 07/22/2022] [Indexed: 01/28/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in multiorgan damage primarily mediated by viral infiltration via angiotensin-converting enzyme-2 receptors on the surface of cells. A primary symptom for many patients is exertional dyspnoea which may persist even beyond recovery from the viral infection. Respiratory muscle (RM) performance was hypothesised as a contributing factor to the severity of coronavirus disease 2019 (COVID-19) symptoms, such as dyspnoea, and outcomes. This was attributed to similarities between patient populations at elevated risk for severe COVID-19 symptoms and those with a greater likelihood of baseline RM weakness and the effects of prolonged mechanical ventilation. More recent evidence suggests that SARS-CoV-2 infection itself may cause damage to the RM, and many patients who have recovered report persistent dyspnoea despite having mild cases, normal lung function or undamaged lung parenchyma. These more recent findings suggest that the role of RM in the persistent dyspnoea due to COVID-19 may be more substantial than originally hypothesised. Therefore, screening for RM weakness and providing interventions to improve RM performance appears to be important for patients with COVID-19. This article will review the impact of SARS-CoV-2 infection on RM performance and provide clinical recommendations for screening RM performance and treatment interventions.
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Affiliation(s)
- Richard Severin
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA,Department of Physical Therapy, Robbins College of Health and Human Sciences, Baylor University, Waco, TX, USA,Healthy Living for Pandemic Event Protection (HL-PIVOT) Network, Chicago, IL, USA,Corresponding author: Richard Severin ()
| | - Colin K. Franz
- The Shirley Ryan Ability Lab, Chicago, IL, USA,Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Ellen Farr
- The Shirley Ryan Ability Lab, Chicago, IL, USA,Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Cristiane Meirelles
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Ross Arena
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA,Healthy Living for Pandemic Event Protection (HL-PIVOT) Network, Chicago, IL, USA
| | - Shane A. Phillips
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA,Healthy Living for Pandemic Event Protection (HL-PIVOT) Network, Chicago, IL, USA
| | - Sam Bond
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA,Healthy Living for Pandemic Event Protection (HL-PIVOT) Network, Chicago, IL, USA
| | | | - Mark Faghy
- Healthy Living for Pandemic Event Protection (HL-PIVOT) Network, Chicago, IL, USA,Human Sciences Research Centre, University of Derby, Derby, UK
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10
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Kovak N, DeRosa S, Fischer C, Murphy K, Wolf J. Inclusion of airway pressure release ventilation in the management of respiratory failure and refractory hypercapnia in a dog. J Vet Emerg Crit Care (San Antonio) 2022; 32:817-823. [PMID: 36031749 DOI: 10.1111/vec.13231] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe the use of airway pressure release ventilation (APRV) to relieve hypercapnia in a dog undergoing mechanical ventilation. CASE SUMMARY A 3-month-old male Shar-Pei mix presented to the emergency department with suspected noncardiogenic pulmonary edema. Due to severe hypercapnia, mechanical ventilation was initiated. The hypercapnia failed to improve with conventional pressure control mechanical ventilation, bronchodilator administration, suctioning, or endotracheal tube replacement. The dog was transitioned to APRV and maintained in this mode for 36 hours. A modified APRV protocol in which inverse inspiratory to expiratory ratios ranged from 4.3:1 to 6.0:1 was utilized, resulting in a drastic improvement in the patient's hypercapnia. The patient eventually was transitioned off the ventilator, and no respiratory abnormalities have been noted at subsequent recheck examinations. NEW OR UNIQUE INFORMATION PROVIDED This case documents the first use of APRV to relieve refractory hypercapnia in a dog undergoing mechanical ventilation and is one of the only recorded cases of using APRV for this purpose in the medical literature at large. APRV may be considered in cases of hypercapnia when traditional therapies fail, although caution is warranted as this mode of ventilation can also worsen hypercapnia.
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Affiliation(s)
- Natalie Kovak
- Department of Clinical Sciences and Advanced Medicine, Matthew J. Ryan Veterinary Hospital, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Sage DeRosa
- Department of Clinical Sciences and Advanced Medicine, Matthew J. Ryan Veterinary Hospital, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Christiana Fischer
- Department of Clinical Sciences and Advanced Medicine, Matthew J. Ryan Veterinary Hospital, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Kellyann Murphy
- Department of Clinical Sciences and Advanced Medicine, Matthew J. Ryan Veterinary Hospital, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Jacob Wolf
- Department of Clinical Sciences and Advanced Medicine, Matthew J. Ryan Veterinary Hospital, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
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11
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Nieman G, Kollisch-Singule M, Ramcharran H, Satalin J, Blair S, Gatto LA, Andrews P, Ghosh A, Kaczka DW, Gaver D, Bates J, Habashi NM. Unshrinking the baby lung to calm the VILI vortex. Crit Care 2022; 26:242. [PMID: 35934707 PMCID: PMC9357329 DOI: 10.1186/s13054-022-04105-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/12/2022] [Indexed: 02/07/2023] Open
Abstract
A hallmark of ARDS is progressive shrinking of the ‘baby lung,’ now referred to as the ventilator-induced lung injury (VILI) ‘vortex.’ Reducing the risk of the VILI vortex is the goal of current ventilation strategies; unfortunately, this goal has not been achieved nor has mortality been reduced. However, the temporal aspects of a mechanical breath have not been considered. A brief expiration prevents alveolar collapse, and an extended inspiration can recruit the atelectatic lung over hours. Time-controlled adaptive ventilation (TCAV) is a novel ventilator approach to achieve these goals, since it considers many of the temporal aspects of dynamic lung mechanics.
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Affiliation(s)
- Gary Nieman
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Michaela Kollisch-Singule
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Harry Ramcharran
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Joshua Satalin
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA.
| | - Sarah Blair
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Penny Andrews
- Department of Medicine, University of Maryland, Baltimore, MD, USA
| | - Auyon Ghosh
- Department of Surgery, SUNY Upstate Medical Center, SUNY Upstate, 750 East Adams St., Syracuse, NY, 13210, USA
| | - David W Kaczka
- Departments of Anesthesia, Biomedical Engineering, and Radiology, University of Iowa, Iowa City, IA, USA
| | - Donald Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Jason Bates
- Department of Medicine, University of Vermont, Burlington, VT, USA
| | - Nader M Habashi
- Department of Medicine, University of Maryland, Baltimore, MD, USA
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12
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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] [Abstract] [Key Words] [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
| | - 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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13
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Abstract
Contemplating the future should be grounded in history. The rise of post-polio ICUs was inextricably related to mechanical ventilation. Critically ill patients who developed acute respiratory failure often had "congestive atelectasis" (ie, a term used to describe ARDS prior to 1967). Initial mechanical ventilation strategies for treating this condition and others inadvertently led to ventilator-induced lung injury. Both injurious ventilation and later use of overly cautious weaning practices resulted from both limited technology and understanding of ARDS and other aspects of critical illness. The resulting misperceptions, misconceptions, and missed opportunities took decades to rectify and in some instances still persist. This suggests a reluctance to acknowledge that all therapeutic strategies reflect the historical period in which they were developed and the corresponding limited understanding of ARDS pathophysiology at that time. We are at the threshold of a revolutionary moment in critical care. The confluence of enormous clinical data production, massive computing power, advances in understanding the biomolecular and genetic aspects of critical illness, and the emergence of neural networks will have enormous impact on how critical care is practiced in the decades to come. Therefore, it is imperative we understand the long-crooked path needed to reach the era of protective ventilation in order to avoid similar mistakes moving forward. The emerging era is as difficult to fathom as our current practices and technologies were to those practicing 60 years ago. This review explores the history of mechanical ventilation in treating ARDS, describes current protective ventilation strategies, and speculates how ARDS management might look 20 years from now.
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Affiliation(s)
- Richard H Kallet
- Department of Anesthesia and Perioperative Care, University of California, San Francisco at San Francisco General Hospital, San Francisco, California.
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14
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Cheng J, Ma A, Dong M, Zhou Y, Wang B, Xue Y, Wang P, Yang J, Kang Y. Does airway pressure release ventilation offer new hope for treating acute respiratory distress syndrome? JOURNAL OF INTENSIVE MEDICINE 2022; 2:241-248. [PMID: 36785647 PMCID: PMC8958099 DOI: 10.1016/j.jointm.2022.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/30/2022] [Accepted: 02/16/2022] [Indexed: 01/01/2023]
Abstract
Mechanical ventilation (MV) is an essential life support method for patients with acute respiratory distress syndrome (ARDS), which is one of the most common critical illnesses with high mortality in the intensive care unit (ICU). A lung-protective ventilation strategy based on low tidal volume (LTV) has been recommended since a few years; however, as this did not result in a significant decrease of ARDS-related mortality, a more optimal ventilation mode was required. Airway pressure release ventilation (APRV) is an old method defined as a continuous positive airway pressure (CPAP) with a brief intermittent release phase based on the open lung concept; it also perfectly fits the ARDS treatment principle. Despite this, APRV has not been widely used in the past, rather only as a rescue measure for ARDS patients who are difficult to oxygenate. Over recent years, with an increased understanding of the pathophysiology of ARDS, APRV has been reproposed to improve patient prognosis. Nevertheless, this mode is still not routinely used in ARDS patients given its vague definition and complexity. Consequently, in this paper, we summarize the studies that used APRV in ARDS, including adults, children, and animals, to illustrate the settings of parameters, effectiveness in the population, safety (especially in children), incidence, and mechanism of ventilator-induced lung injury (VILI) and effects on extrapulmonary organs. Finally, we found that APRV is likely associated with improvement in ARDS outcomes, and does not increase injury to the lungs and other organs, thereby indicating that personalized APRV settings may be the new hope for ARDS treatment.
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Affiliation(s)
| | | | | | | | | | | | | | - Jing Yang
- Corresponding authors: Yan Kang and Jing Yang, Department of Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China.
| | - Yan Kang
- Corresponding authors: Yan Kang and Jing Yang, Department of Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China.
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15
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Time-Controlled Adaptive Ventilation Versus Volume-Controlled Ventilation in Experimental Pneumonia. Crit Care Med 2021; 49:140-150. [PMID: 33060501 DOI: 10.1097/ccm.0000000000004675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVES We hypothesized that a time-controlled adaptive ventilation strategy would open and stabilize alveoli by controlling inspiratory and expiratory duration. Time-controlled adaptive ventilation was compared with volume-controlled ventilation at the same levels of mean airway pressure and positive end-release pressure (time-controlled adaptive ventilation)/positive end-expiratory pressure (volume-controlled ventilation) in a Pseudomonas aeruginosa-induced pneumonia model. DESIGN Animal study. SETTING Laboratory investigation. SUBJECTS Twenty-one Wistar rats. INTERVENTIONS Twenty-four hours after pneumonia induction, Wistar rats (n = 7) were ventilated with time-controlled adaptive ventilation (tidal volume = 8 mL/kg, airway pressure release ventilation for a Thigh = 0.75-0.85 s, release pressure (Plow) set at 0 cm H2O, and generating a positive end-release pressure = 1.6 cm H2O applied for Tlow = 0.11-0.14 s). The expiratory flow was terminated at 75% of the expiratory flow peak. An additional 14 animals were ventilated using volume-controlled ventilation, maintaining similar time-controlled adaptive ventilation levels of positive end-release pressure (positive end-expiratory pressure=1.6 cm H2O) and mean airway pressure = 10 cm H2O. Additional nonventilated animals (n = 7) were used for analysis of molecular biology markers. MEASUREMENTS AND MAIN RESULTS After 1 hour of mechanical ventilation, the heterogeneity score, the expression of pro-inflammatory biomarkers interleukin-6 and cytokine-induced neutrophil chemoattractant-1 in lung tissue were significantly lower in the time-controlled adaptive ventilation than volume-controlled ventilation with similar mean airway pressure groups (p = 0.008, p = 0.011, and p = 0.011, respectively). Epithelial cell integrity, measured by E-cadherin tissue expression, was higher in time-controlled adaptive ventilation than volume-controlled ventilation with similar mean airway pressure (p = 0.004). Time-controlled adaptive ventilation animals had bacteremia counts lower than volume-controlled ventilation with similar mean airway pressure animals, while time-controlled adaptive ventilation and volume-controlled ventilation with similar positive end-release pressure animals had similar colony-forming unit counts. In addition, lung edema and cytokine-induced neutrophil chemoattractant-1 gene expression were more reduced in time-controlled adaptive ventilation than volume-controlled ventilation with similar positive end-release pressure groups. CONCLUSIONS In the model of pneumonia used herein, at the same tidal volume and mean airway pressure, time-controlled adaptive ventilation, compared with volume-controlled ventilation, was associated with less lung damage and bacteremia and reduced gene expression of mediators associated with inflammation.
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16
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Kallet RH, Lipnick MS, Burns GD. The Nature of Recruitment and De-Recruitment and Its Implications for Management of ARDS. Respir Care 2021; 66:510-530. [PMID: 33051254 PMCID: PMC9994058 DOI: 10.4187/respcare.08280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recruitment maneuvers in ARDS are used to improve oxygenation and lung mechanics by applying high airway pressures to reopen collapsed or obstructed peripheral airways and alveoli. In the early 1990s, recruitment maneuvers became a central feature of a variant form of lung-protective ventilation known as open-lung ventilation. This strategy is based on the belief that repetitive opening and closing of distal airspaces induces shear injury and therefore contributes both to ventilator-induced lung injury and ARDS-associated mortality. However, the largest multi-center randomized controlled trial of open-lung ventilation in moderate to severe ARDS reported that recruitment maneuver plateau pressures of 50-60 cm H2O were associated with significantly higher mortality compared to traditional lung-protective ventilation. Despite being based on well conducted preclinical and clinical recruitment maneuver studies, the higher mortality associated with the open-lung ventilation strategy requires re-examining the assumptions and conclusions drawn from those previous studies. This narrative review examines the evidence used to design recruitment maneuver strategies. We also review the radiologic, rheologic, and histopathologic evidence regarding the nature of lung injury and the phenomena of recruitment and de-recruitment as it informs our perceptions of recruitment potential in ARDS. Major lung-protective ventilation clinical trial data and other clinical data are also examined to assess the practical necessity of recruitment maneuvers in ARDS and whether a subset of cases might benefit from pursuing recruitment maneuver therapy. Finally, a less a radical approach to recruitment maneuvers is offered that might achieve the goals of recruitment maneuvers with less risk of harm.
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Affiliation(s)
- Richard H Kallet
- Respiratory Care Division, Department of Anesthesia and Perioperative Care, University of California San Francisco at San Francisco General Hospital, San Francisco, California.
| | - Michael S Lipnick
- Critical Care Division, Department of Anesthesia and Perioperative Care, University of California San Francisco at San Francisco General Hospital, San Francisco, California
| | - Gregory D Burns
- Respiratory Care Division, Department of Anesthesia and Perioperative Care, University of California San Francisco at San Francisco General Hospital, San Francisco, California
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17
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Mandell EW, Mattson C, Seedorf G, Ryan S, Gonzalez T, Wallbank A, Bye EM, Abman SH, Smith BJ. Antenatal Endotoxin Impairs Lung Mechanics and Increases Sensitivity to Ventilator-Induced Lung Injury in Newborn Rat Pups. Front Physiol 2021; 11:614283. [PMID: 33519519 PMCID: PMC7838561 DOI: 10.3389/fphys.2020.614283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/15/2020] [Indexed: 11/24/2022] Open
Abstract
Perinatal inflammation due to chorioamnionitis and ventilator-induced lung injury (VILI) at birth is independent risk factors for the development of bronchopulmonary dysplasia (BPD). We have previously shown that antenatal endotoxin (ETX) causes abnormal lung structure and function in 2-week-old rats, but whether ETX impairs lung mechanics at birth and increases risk for VILI is unknown. Fetal rats were exposed to 10 μg endotoxin or saline via intra-amniotic injection. At birth (D0) or 7 days (D7), rats received 90 min of lung protective ventilation [PROTECT group; tidal volume (Vt) = 6 ml/kg with positive end expiratory pressure (PEEP) = 2 cmH2O]; P20 ventilation [plateau pressure (Pplat) = 20 cmH2O, PEEP = 0]; or P24 ventilation (Pplat = 24 cmH2O, PEEP = 0, only applied to D7). Prior to prolonged ventilation at D0, endotoxin-exposed rats had decreased compliance and inspiratory capacity (IC) compared to controls. At D7, endotoxin was associated with reduced compliance. High-pressure ventilation (P20 and P24) tended to increase IC and compliance in all saline-treated groups. Ventilation at D0 with P20 increased IC and compliance when applied to saline-treated but not endotoxin-exposed pups. At D7, P24 ventilation of endotoxin-exposed pups increased elastance, bronchoalveolar lavage protein content, and IL-1b and TEN-C mRNA expression in comparison to the saline group. In summary, antenatal endotoxin exposure alters lung mechanics at birth and 1 week of life and increases susceptibility to VILI as observed in lung mechanics, alveolocapillary barrier injury, and inflammatory mRNA expression. We speculate that antenatal inflammation primes the lung for a more marked VILI response, suggesting an adverse synergistic effect of antenatal and postnatal exposures.
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Affiliation(s)
- Erica W Mandell
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Division of Neonatology, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Courtney Mattson
- Department of Bioengineering, College of Engineering, Design, and Computing, University of Colorado Denver
- Anschutz Medical Campus, Aurora, CO, United States
| | - Gregory Seedorf
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Division of Pediatric Pulmonary and Sleep Medicine, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Sharon Ryan
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Division of Neonatology, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Tania Gonzalez
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Division of Neonatology, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Alison Wallbank
- Department of Bioengineering, College of Engineering, Design, and Computing, University of Colorado Denver
- Anschutz Medical Campus, Aurora, CO, United States
| | - Elisa M Bye
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Division of Neonatology, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Steven H Abman
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Division of Pediatric Pulmonary and Sleep Medicine, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Bradford J Smith
- Department of Pediatrics, Pediatric Heart Lung Center, School of Medicine, University of Colorado, Aurora, CO, United States.,Department of Bioengineering, College of Engineering, Design, and Computing, University of Colorado Denver
- Anschutz Medical Campus, Aurora, CO, United States.,Division of Pediatric Pulmonary and Sleep Medicine, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO, United States
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18
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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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19
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Quintero OI, Chavarro PA, Martínez W, García C, Castro AM, Manzano-Nunez R, Ospina GA. Improvement in Lung Insufflation in Spontaneously Breathing Tracheostomized Patients by Using a New Pulmonary Expansion Device: A Pilot Study. J Med Device 2020. [DOI: 10.1115/1.4048801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Abstract
Lung expansion techniques (LETs) are a key component of pulmonary rehabilitation. Nevertheless, these can be limited in tracheostomized patients because of the infraglottic position of tracheostomy cannulas. We propose a novel pulmonary expansion device (PED) that allows deep inspiration with a postinspiratory pause for a few seconds by means of a unidirectional valve and an occlusion/flow release cap. It is equipped with a relief valve that opens at 60 cm H2O in cases in which this threshold is attained. We aimed to evaluate the impact on lung volume and pressure in spontaneously breathing tracheostomized patients subjected to LETs. A single-arm pilot interventional study was conducted in an adult intensive care unit (ICU), including spontaneously breathing tracheostomized patients. 80 treatments were performed on 10 patients with tracheostomies with PED over a period of 3 months. The maximal inspiratory volume (MIV) was significantly increased by using PED (MIV-PED) at both day 1 (725 (600–820) mL versus 1550 (1250–1700) mL, P < 0.001) and day 3 (870 (750–950) mL versus 1662 (1550–1900) mL, P < 0.001). Inspiratory pause pressure (PIP-PED) did not significantly change from day 1 to day 3 (18 (14–20) cm H2O versus 14 (12–22) cm H2O, P = 0.36). The use of the PED in tracheostomy patients acted as an artificial glottis by performing a novel pulmonary re-expansion maneuver, and increased volumes and intrapulmonary pressure with prolongation of maximum inspiration were achieved.
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Affiliation(s)
- Oscar I. Quintero
- Centro de Investigaciones Clínicas, Fundación Valle del Lili, Cali 760026, Colombia
| | - Paola A. Chavarro
- Facultad de Salud, Escuela de Rehabilitación Humana, Universidad del Valle, Cali 760043, Colombia
| | - William Martínez
- Departamento de Neumología, Fundación Valle del Lili, Cali 760026, Colombia; Facultad de ciencias de la salud, Universidad Icesi, Cali 760031, Colombia
| | - Carlos García
- Departamento de Radiología, Fundación Valle del Lili, Cali 760026, Colombia
| | - Andrés M. Castro
- Centro de Investigaciones Clínicas, Fundación Valle del Lili, Cali 760026, Colombia
| | - Ramiro Manzano-Nunez
- Centro de Investigaciones Clínicas, Fundación Valle del Lili, Cali 760026, Colombia
| | - Gustavo A. Ospina
- Departamento de Cuidado Intensivo Adulto, Fundación Valle del Lili, Cali 760026, Colombia
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Mori V, Smith BJ, Suki B, Bates JHT. Modeling Lung Derecruitment in VILI Due to Fluid-Occlusion: The Role of Emergent Behavior. Front Physiol 2020; 11:542744. [PMID: 33192546 PMCID: PMC7662071 DOI: 10.3389/fphys.2020.542744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 10/08/2020] [Indexed: 12/02/2022] Open
Abstract
Ventilator-induced lung injury (VILI) is driven by the processes of volutrauma and atelectrauma, which can act synergistically to compromise the blood-gas barrier. We have postulated that this synergy arises through a rich-get-richer mechanism whereby atelectrauma causes holes to form in the blood-gas barrier while concomitant volutrauma causes susceptible holes to progressively enlarge as VILI worsens. We previously developed an analytical model based on this idea that accurately predicts the progressive increases in lung elastance seen immediately following a recruitment maneuver as VILI progresses over the course of hours. In the present study we extend this model to account for the rate of change of elastance, due to closure of lung units, in the minutes following a recruitment maneuver. We found that the distribution of unit closing velocities throughout the lung can be described by a power law with an exponent of -2 that matches previously published power laws associated with the dynamics of lung recruitment. Our model thus reveals lung collapse as an example of emergent complex behavior and links the dynamics of altered function in the injured lung to structural damage in a way that explains the mechanisms of injury progression arising from the ongoing stresses and strains applied by mechanical ventilation.
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Affiliation(s)
- Vitor Mori
- Department of Medicine, Vermont Lung Center, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
- Department of Telecommunications and Control Engineering, University of São Paulo, São Paulo, Brazil
| | - Bradford J. Smith
- Department of Bioengineering, College of Engineering, Design & Computing, University of Colorado Denver, Aurora, CO, United States
| | - Bela Suki
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Jason H. T. Bates
- Department of Medicine, Vermont Lung Center, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
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Abstract
The 2019-2020 coronavirus pandemic elucidated how a single highly infectious virus can overburden health care systems of even highly economically developed nations. A leading contributor to these concerning outcomes is a lack of available intensive care unit (ICU) beds and mechanical ventilation support. Poorer health is associated with a higher risk for severe respiratory complications from the coronavirus. We hypothesize that impaired respiratory muscle performance is an underappreciated factor contributing to poor outcomes unfolding during the coronavirus pandemic. Although impaired respiratory muscle performance is considered to be rare, it is more frequently encountered in patients with poorer health, in particular obesity. However, measures of respiratory muscle performance are not routinely performed in clinical practice, including those with symptoms such as dyspnea. The purpose of this article is to discuss the potential role of respiratory muscle performance from the perspective of the coronavirus pandemic. We also provide a theoretical patient management model to screen for impaired respiratory muscle performance and intervention, if identified, with the goal of unburdening health care systems during future pandemic crises.
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Niedbalski PJ, Cochran AS, Akinyi TG, Thomen RP, Fugate EM, Lindquist DM, Pratt RG, Cleveland ZI. Preclinical hyperpolarized 129 Xe MRI: ventilation and T 2 * mapping in mouse lungs at 7 T using multi-echo flyback UTE. NMR IN BIOMEDICINE 2020; 33:e4302. [PMID: 32285574 PMCID: PMC7702724 DOI: 10.1002/nbm.4302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/28/2020] [Accepted: 03/07/2020] [Indexed: 05/13/2023]
Abstract
Fast apparent transverse relaxation (short T2 *) is a common obstacle when attempting to perform quantitative 1 H MRI of the lungs. While T2 * times are longer for pulmonary hyperpolarized (HP) gas functional imaging (in particular for gaseous 129 Xe), T2 * can still lead to quantitative inaccuracies for sequences requiring longer echo times (such as diffusion weighted images) or longer readout duration (such as spiral sequences). This is especially true in preclinical studies, where high magnetic fields lead to shorter relaxation times than are typically seen in human studies. However, the T2 * of HP 129 Xe in the most common animal model of human disease (mice) has not been reported. Herein, we present a multi-echo radial flyback imaging sequence and use it to measure HP 129 Xe T2 * at 7 T under a variety of respiratory conditions. This sequence mitigates the impact of T1 relaxation outside the animal by using multiple gradient-refocused echoes to acquire images at a number of effective echo times for each RF excitation. After validating the sequence using a phantom containing water doped with superparamagnetic iron oxide nanoparticles, we measured the 129 Xe T2 * in vivo for 10 healthy C57Bl/6 J mice and found T2 * ~ 5 ms in the lung airspaces. Interestingly, T2 * was relatively constant over all experimental conditions, and varied significantly with sex, but not age, mass, or the O2 content of the inhaled gas mixture. These results are discussed in the context of T2 * relaxation within porous media.
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Affiliation(s)
- Peter J. Niedbalski
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Alexander S. Cochran
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Teckla G. Akinyi
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Robert P. Thomen
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Elizabeth M. Fugate
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Diana M. Lindquist
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Ronald G. Pratt
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Zackary I. Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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23
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Matuszak J, Tabuchi A, Kuebler WM. Ventilation and Perfusion at the Alveolar Level: Insights From Lung Intravital Microscopy. Front Physiol 2020; 11:291. [PMID: 32308629 PMCID: PMC7145899 DOI: 10.3389/fphys.2020.00291] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/16/2020] [Indexed: 01/13/2023] Open
Abstract
Intravital microscopy (IVM) offers unique possibilities for the observation of biological processes and disease related mechanisms in vivo. Especially for anatomically complex and dynamic organs such as the lung and its main functional unit, the alveolus, IVM provides exclusive advantages in terms of spatial and temporal resolution. By the use of lung windows, which have advanced and improved over time, direct access to the lung surface is provided. In this review we will discuss two main topics, namely alveolar dynamics and perfusion from the perspective of IVM-based studies. Of special interest are unanswered questions regarding alveolar dynamics such as: What are physiologic alveolar dynamics? How do these dynamics change under pathologic conditions and how do those changes contribute to ventilator-induced lung injury? How can alveolar dynamics be targeted in a beneficial way? With respect to alveolar perfusion IVM has propelled our understanding of the pulmonary microcirculation and its perfusion, as well as pulmonary vasoreactivity, permeability and immunological aspects. Whereas the general mechanism behind these processes are understood, we still lack a proper understanding of the complex, multidimensional interplay between alveolar ventilation and microvascular perfusion, capillary recruitment, or vascular immune responses under physiologic and pathologic conditions. These are only part of the unanswered questions and problems, which we still have to overcome. IVM as the tool of choice might allow us to answer part of these questions within the next years or decades. As every method, IVM has advantages as well as limitations, which have to be taken into account for data analysis and interpretation, which will be addressed in this review.
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Affiliation(s)
- Jasmin Matuszak
- Institute of Physiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Arata Tabuchi
- The Keenan Research Centre for Biomedical Science at St. Michael’s, Toronto, ON, Canada
| | - Wolfgang M. Kuebler
- Institute of Physiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Departments of Surgery and Physiology, University of Toronto, Toronto, ON, Canada
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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] [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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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] [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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Gama de Abreu M, Schultz M, Pelosi P. Intraoperative Ventilation Strategies to Reduce Pulmonary Complications in Obese Patients-Reply. JAMA 2019; 322:1829. [PMID: 31714982 DOI: 10.1001/jama.2019.14400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Marcelo Gama de Abreu
- Department of Anesthesiology and Intensive Care Medicine, Technische Universität Dresden, Dresden, Germany
| | - Marcus Schultz
- Department of Anesthesiology, University of Amsterdam, Amsterdam, the Netherlands
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
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Biological Response to Time-Controlled Adaptive Ventilation Depends on Acute Respiratory Distress Syndrome Etiology. Crit Care Med 2019; 46:e609-e617. [PMID: 29485489 DOI: 10.1097/ccm.0000000000003078] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES To compare a time-controlled adaptive ventilation strategy, set in airway pressure release ventilation mode, versus a protective mechanical ventilation strategy in pulmonary and extrapulmonary acute respiratory distress syndrome with similar mechanical impairment. DESIGN Animal study. SETTING Laboratory investigation. SUBJECTS Forty-two Wistar rats. INTERVENTIONS Pulmonary acute respiratory distress syndrome and extrapulmonary acute respiratory distress syndrome were induced by instillation of Escherichia coli lipopolysaccharide intratracheally or intraperitoneally, respectively. After 24 hours, animals were randomly assigned to receive 1 hour of volume-controlled ventilation (n = 7/etiology) or time-controlled adaptive ventilation (n = 7/etiology) (tidal volume = 8 mL/kg). Time-controlled adaptive ventilation consisted of the application of continuous positive airway pressure 2 cm H2O higher than baseline respiratory system peak pressure for a time (Thigh) of 0.75-0.85 seconds. The release pressure (Plow = 0 cm H2O) was applied for a time (Tlow) of 0.11-0.18 seconds. Tlow was set to target an end-expiratory flow to peak expiratory flow ratio of 75%. Nonventilated animals (n = 7/etiology) were used for Diffuse Alveolar Damage and molecular biology markers analyses. MEASUREMENT AND MAIN RESULTS Time-controlled adaptive ventilation increased mean respiratory system pressure regardless of acute respiratory distress syndrome etiology. The Diffuse Alveolar Damage score was lower in time-controlled adaptive ventilation compared with volume-controlled ventilation in pulmonary acute respiratory distress syndrome and lower in time-controlled adaptive ventilation than nonventilated in extrapulmonary acute respiratory distress syndrome. In pulmonary acute respiratory distress syndrome, volume-controlled ventilation, but not time-controlled adaptive ventilation, increased the expression of amphiregulin, vascular cell adhesion molecule-1, and metalloproteinase-9. Collagen density was higher, whereas expression of decorin was lower in time-controlled adaptive ventilation than nonventilated, independent of acute respiratory distress syndrome etiology. In pulmonary acute respiratory distress syndrome, but not in extrapulmonary acute respiratory distress syndrome, time-controlled adaptive ventilation increased syndecan expression. CONCLUSION In pulmonary acute respiratory distress syndrome, time-controlled adaptive ventilation led to more pronounced beneficial effects on expression of biomarkers related to overdistension and extracellular matrix homeostasis.
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Scaramuzzo G, Broche L, Pellegrini M, Porra L, Derosa S, Tannoia AP, Marzullo A, Borges JB, Bayat S, Bravin A, Larsson A, Perchiazzi G. The Effect of Positive End-Expiratory Pressure on Lung Micromechanics Assessed by Synchrotron Radiation Computed Tomography in an Animal Model of ARDS. J Clin Med 2019; 8:E1117. [PMID: 31357677 PMCID: PMC6723999 DOI: 10.3390/jcm8081117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/17/2019] [Accepted: 07/25/2019] [Indexed: 02/06/2023] Open
Abstract
Modern ventilatory strategies are based on the assumption that lung terminal airspaces act as isotropic balloons that progressively accommodate gas. Phase contrast synchrotron radiation computed tomography (PCSRCT) has recently challenged this concept, showing that in healthy lungs, deflation mechanisms are based on the sequential de-recruitment of airspaces. Using PCSRCT scans in an animal model of acute respiratory distress syndrome (ARDS), this study examined whether the numerosity (ASnum) and dimension (ASdim) of lung airspaces change during a deflation maneuver at decreasing levels of positive end-expiratory pressure (PEEP) at 12, 9, 6, 3, and 0 cmH2O. Deflation was associated with significant reduction of ASdim both in the whole lung section (passing from from 13.1 ± 2.0 at PEEP 12 to 7.6 ± 4.2 voxels at PEEP 0) and in single concentric regions of interest (ROIs). However, the regression between applied PEEP and ASnum was significant in the whole slice (ranging from 188 ± 52 at PEEP 12 to 146.4 ± 96.7 at PEEP 0) but not in the single ROIs. This mechanism of deflation in which reduction of ASdim is predominant, differs from the one observed in healthy conditions, suggesting that the peculiar alveolar micromechanics of ARDS might play a role in the deflation process.
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Affiliation(s)
- Gaetano Scaramuzzo
- Department of Morphology, Surgery and Experimental Medicine, Ferrara University, 44121 Ferrara, Italy
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, 75185 Uppsala, Sweden
| | - Ludovic Broche
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, 75185 Uppsala, Sweden
| | - Mariangela Pellegrini
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, 75185 Uppsala, Sweden
- Department of Anesthesia and Intensive Care, Uppsala University Hospital, 75185 Uppsala, Sweden
| | - Liisa Porra
- Department of Physics, University of Helsinki, FI-00014 Helsinki, Finland
- Helsinki University Hospital, FI-00029 Helsinki, Finland
| | - Savino Derosa
- Department of Emergency and Organ Transplant, Bari University, 70124 Bari, Italy
| | | | - Andrea Marzullo
- Department of Emergency and Organ Transplant, Bari University, 70124 Bari, Italy
| | - João Batista Borges
- Centre for Human and Applied Physiological Sciences, Faculty of Sciences and Medicine, King's College, London WC2R 2LS, UK
| | - Sam Bayat
- The European Synchrotron Radiation Facility, 38043 Grenoble, France
- INSERM UA7, Synchrotron Radiation for Biomedicine (STROBE) Laboratory, University of Grenoble Alpes, 38043 Grenoble, France
| | - Alberto Bravin
- The European Synchrotron Radiation Facility, 38043 Grenoble, France
| | - Anders Larsson
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, 75185 Uppsala, Sweden
| | - Gaetano Perchiazzi
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, 75185 Uppsala, Sweden.
- Department of Anesthesia and Intensive Care, Uppsala University Hospital, 75185 Uppsala, Sweden.
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Scaramuzzo G, Broche L, Pellegrini M, Porra L, Derosa S, Tannoia AP, Marzullo A, Borges JB, Bayat S, Bravin A, Larsson A, Perchiazzi G. Regional Behavior of Airspaces During Positive Pressure Reduction Assessed by Synchrotron Radiation Computed Tomography. Front Physiol 2019; 10:719. [PMID: 31231245 PMCID: PMC6567926 DOI: 10.3389/fphys.2019.00719] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 05/23/2019] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION The mechanisms of lung inflation and deflation are only partially known. Ventilatory strategies to support lung function rely upon the idea that lung alveoli are isotropic balloons that progressively inflate or deflate and that lung pressure/volume curves derive only by the interplay of critical opening pressures, critical closing pressures, lung history, and position of alveoli inside the lung. This notion has been recently challenged by subpleural microscopy, magnetic resonance, and computed tomography (CT). Phase-contrast synchrotron radiation CT (PC-SRCT) can yield in vivo images at resolutions higher than conventional CT. OBJECTIVES We aimed to assess the numerosity (ASden) and the extension of the surface of airspaces (ASext) in healthy conditions at different volumes, during stepwise lung deflation, in concentric regions of the lung. METHODS The study was conducted in seven anesthetized New Zealand rabbits. They underwent PC-SRCT scans (resolution of 47.7 μm) of the lung at five decreasing positive end expiratory pressure (PEEP) levels of 12, 9, 6, 3, and 0 cmH2O during end-expiratory holds. Three concentric regions of interest (ROIs) of the lung were studied: subpleural, mantellar, and core. The images were enhanced by phase contrast algorithms. ASden and ASext were computed by using the Image Processing Toolbox for MatLab. Statistical tests were used to assess any significant difference determined by PEEP or ROI on ASden and ASext. RESULTS When reducing PEEP, in each ROI the ASden significantly decreased. Conversely, ASext variation was not significant except for the core ROI. In the latter, the angular coefficient of the regression line was significantly low. CONCLUSION The main mechanism behind the decrease in lung volume at PEEP reduction is derecruitment. In our study involving lung regions laying on isogravitational planes and thus equally influenced by gravitational forces, airspace numerosity and extension of surface depend on the local mechanical properties of the lung.
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Affiliation(s)
- Gaetano Scaramuzzo
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Ludovic Broche
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- The European Synchrotron Radiation Facility, Grenoble, France
- INSERM UA7, Synchrotron Radiation for Biomedicine (STROBE) Laboratory, Grenoble Alpes University, Amiens, France
| | - Mariangela Pellegrini
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Department of Anesthesia and Intensive Care, Uppsala University Hospital, Uppsala, Sweden
| | - Liisa Porra
- Department of Physics, Faculty of Mathematics and Natural Sciences, University of Helsinki, Helsinki, Finland
- Helsinki University Central Hospital, Helsinki, Finland
| | - Savino Derosa
- Department of Emergency and Organ Transplant, University of Bari Aldo Moro, Bari, Italy
| | | | - Andrea Marzullo
- Department of Emergency and Organ Transplant, University of Bari Aldo Moro, Bari, Italy
| | - Joao Batista Borges
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Centre for Human and Applied Physiological Sciences, Faculty of Sciences and Medicine, King’s College London, London, United Kingdom
| | - Sam Bayat
- INSERM UA7, Synchrotron Radiation for Biomedicine (STROBE) Laboratory, Grenoble Alpes University, Amiens, France
| | - Alberto Bravin
- The European Synchrotron Radiation Facility, Grenoble, France
| | - Anders Larsson
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Gaetano Perchiazzi
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Department of Anesthesia and Intensive Care, Uppsala University Hospital, Uppsala, Sweden
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30
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LIU TIANYA, WANG YUXING, LIU XIAOYU, YUAN LAN, LI DEYU, QIAO HUITING, FAN YUBO. EFFECTS OF ALVEOLAR MORPHOLOGY ON ALVEOLAR MECHANICS: AN EXPERIMENTAL STUDY OF MOUSE LUNG BASED ON TWO- AND THREE-DIMENSIONAL IMAGING METHODS. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419500271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding alveolar mechanics is important for preventing the possible lung injuries during mechanical ventilation. Alveolar clusters with smaller size are found having lower compliance in two-dimensional studies. But the influence of alveolar shape on compliance is unclear. In order to investigate how alveolar morphology affects their behavior, we tracked subpleural alveoli of isolated mouse lungs during quasi-static ventilation using two- and three-dimensional imaging techniques. Results showed that alveolar clusters with smaller size and more spherical shape had lower compliance. There was a better correlation of sphericity rather than circularity with alveolar compliance. The compliance of clusters with great shape change was larger than that with relatively slight shape change. These findings suggest the contribution of lung heterogeneous expansion to lung injuries associated with mechanical ventilation.
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Affiliation(s)
- TIANYA LIU
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - YUXING WANG
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - XIAOYU LIU
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - LAN YUAN
- Beijing Key Laboratory of Rehabilitation Engineering for Elderly, National Research Center for Rehabilitation Technical Aids, Beijing 100176, P. R. China
| | - DEYU LI
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - HUITING QIAO
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - YUBO FAN
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
- Medical and Health Analysis Center, Peking University, Beijing 100191, P. R. China
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31
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Morton SE, Knopp JL, Chase JG, Docherty P, Howe SL, Möller K, Shaw GM, Tawhai M. Optimising mechanical ventilation through model-based methods and automation. ANNUAL REVIEWS IN CONTROL 2019; 48:369-382. [PMID: 36911536 PMCID: PMC9985488 DOI: 10.1016/j.arcontrol.2019.05.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/09/2019] [Accepted: 05/01/2019] [Indexed: 06/11/2023]
Abstract
Mechanical ventilation (MV) is a core life-support therapy for patients suffering from respiratory failure or acute respiratory distress syndrome (ARDS). Respiratory failure is a secondary outcome of a range of injuries and diseases, and results in almost half of all intensive care unit (ICU) patients receiving some form of MV. Funding the increasing demand for ICU is a major issue and MV, in particular, can double the cost per day due to significant patient variability, over-sedation, and the large amount of clinician time required for patient management. Reducing cost in this area requires both a decrease in the average duration of MV by improving care, and a reduction in clinical workload. Both could be achieved by safely automating all or part of MV care via model-based dynamic systems modelling and control methods are ideally suited to address these problems. This paper presents common lung models, and provides a vision for a more automated future and explores predictive capacity of some current models. This vision includes the use of model-based methods to gain real-time insight to patient condition, improve safety through the forward prediction of outcomes to changes in MV, and develop virtual patients for in-silico design and testing of clinical protocols. Finally, the use of dynamic systems models and system identification to guide therapy for improved personalised control of oxygenation and MV therapy in the ICU will be considered. Such methods are a major part of the future of medicine, which includes greater personalisation and predictive capacity to both optimise care and reduce costs. This review thus presents the state of the art in how dynamic systems and control methods can be applied to transform this core area of ICU medicine.
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Affiliation(s)
- Sophie E Morton
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Jennifer L Knopp
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - J Geoffrey Chase
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Paul Docherty
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Sarah L Howe
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Geoffrey M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand
| | - Merryn Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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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: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [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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33
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Predictive Virtual Patient Modelling of Mechanical Ventilation: Impact of Recruitment Function. Ann Biomed Eng 2019; 47:1626-1641. [PMID: 30927170 DOI: 10.1007/s10439-019-02253-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/22/2019] [Indexed: 10/27/2022]
Abstract
Mechanical ventilation is a life-support therapy for intensive care patients suffering from respiratory failure. To reduce the current rate of ventilator-induced lung injury requires ventilator settings that are patient-, time-, and disease-specific. A common lung protective strategy is to optimise the level of positive end-expiratory pressure (PEEP) through a recruitment manoeuvre to prevent alveolar collapse at the end of expiration and to improve gas exchange through recruitment of additional alveoli. However, this process can subject parts of the lung to excessively high pressures or volumes. This research significantly extends and more robustly validates a previously developed pulmonary mechanics model to predict lung mechanics throughout recruitment manoeuvres. In particular, the process of recruitment is more thoroughly investigated and the impact of the inclusion of expiratory data when estimating peak inspiratory pressure is assessed. Data from the McREM trial and CURE pilot trial were used to test model predictive capability and assumptions. For PEEP changes of up to and including 14 cmH2O, the parabolic model was shown to improve peak inspiratory pressure prediction resulting in less than 10% absolute error in the CURE cohort and 16% in the McREM cohort. The parabolic model also better captured expiratory mechanics than the exponential model for both cohorts.
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van der Zee P, Gommers D. Recruitment Maneuvers and Higher PEEP, the So-Called Open Lung Concept, in Patients with ARDS. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2019; 23:73. [PMID: 30850004 PMCID: PMC6408810 DOI: 10.1186/s13054-019-2365-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2019. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2019. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.
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Affiliation(s)
- Philip van der Zee
- Department of Adult Intensive Care Medicine, Erasmus MC, Erasmus University Rotterdam, Rotterdam, The Netherlands
| | - Diederik Gommers
- Department of Adult Intensive Care Medicine, Erasmus MC, Erasmus University Rotterdam, Rotterdam, The Netherlands.
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Crockett DC, Cronin JN, Bommakanti N, Chen R, Hahn CEW, Hedenstierna G, Larsson A, Farmery AD, Formenti F. Tidal changes in PaO 2 and their relationship to cyclical lung recruitment/derecruitment in a porcine lung injury model. Br J Anaesth 2018; 122:277-285. [PMID: 30686314 PMCID: PMC6354046 DOI: 10.1016/j.bja.2018.09.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/21/2018] [Accepted: 09/10/2018] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Tidal recruitment/derecruitment (R/D) of collapsed regions in lung injury has been presumed to cause respiratory oscillations in the partial pressure of arterial oxygen (PaO2). These phenomena have not yet been studied simultaneously. We examined the relationship between R/D and PaO2 oscillations by contemporaneous measurement of lung-density changes and PaO2. METHODS Five anaesthetised pigs were studied after surfactant depletion via a saline-lavage model of R/D. The animals were ventilated with a mean fraction of inspired O2 (FiO2) of 0.7 and a tidal volume of 10 ml kg-1. Protocolised changes in pressure- and volume-controlled modes, inspiratory:expiratory ratio (I:E), and three types of breath-hold manoeuvres were undertaken. Lung collapse and PaO2 were recorded using dynamic computed tomography (dCT) and a rapid PaO2 sensor. RESULTS During tidal ventilation, the expiratory lung collapse increased when I:E <1 [mean (standard deviation) lung collapse=15.7 (8.7)%; P<0.05], but the amplitude of respiratory PaO2 oscillations [2.2 (0.8) kPa] did not change during the respiratory cycle. The expected relationship between respiratory PaO2 oscillation amplitude and R/D was therefore not clear. Lung collapse increased during breath-hold manoeuvres at end-expiration and end-inspiration (14% vs 0.9-2.1%; P<0.0001). The mean change in PaO2 from beginning to end of breath-hold manoeuvres was significantly different with each type of breath-hold manoeuvre (P<0.0001). CONCLUSIONS This study in a porcine model of collapse-prone lungs did not demonstrate the expected association between PaO2 oscillation amplitude and the degree of recruitment/derecruitment. The results suggest that changes in pulmonary ventilation are not the sole determinant of changes in PaO2 during mechanical ventilation in lung injury.
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Affiliation(s)
- D C Crockett
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
| | - J N Cronin
- Centre for Human and Applied Physiological Sciences, King's College, London, UK
| | - N Bommakanti
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK; Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - R Chen
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK
| | - C E W Hahn
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK
| | - G Hedenstierna
- Hedenstierna Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - A Larsson
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - A D Farmery
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK
| | - F Formenti
- Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK; Centre for Human and Applied Physiological Sciences, King's College, London, UK; Department of Biomechanics, University of Nebraska Omaha, Omaha, NE, USA.
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36
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Satalin J, Habashi NM, Nieman GF. Never give the lung the opportunity to collapse. TRENDS IN ANAESTHESIA AND CRITICAL CARE 2018. [DOI: 10.1016/j.tacc.2018.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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37
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Preemptive Mechanical Ventilation Based on Dynamic Physiology in the Alveolar Microenvironment: Novel Considerations of Time-Dependent Properties of the Respiratory System. J Trauma Acute Care Surg 2018; 85:1081-1091. [PMID: 30124627 DOI: 10.1097/ta.0000000000002050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The acute respiratory distress syndrome (ARDS) remains a serious clinical problem with the current treatment being supportive in the form of mechanical ventilation. However, mechanical ventilation can be a double-edged sword; if set properly, it can significantly reduce ARDS associated mortality but if set improperly it can have unintended consequences causing a secondary ventilator induced lung injury (VILI). The hallmark of ARDS pathology is a heterogeneous lung injury, which predisposes the lung to a secondary VILI. The current standard of care approach is to wait until ARDS is well established and then apply a low tidal volume (LVt) strategy to avoid over-distending the remaining normal lung. However, even with the use of LVt strategy, the mortality of ARDS remains unacceptably high at ~40%. In this review, we analyze the lung pathophysiology associated with ARDS that renders the lung highly vulnerable to a secondary VILI. The current standard of care LVt strategy is critiqued as well as new strategies used in combination with LVt to protect the lung. Using the current understanding of alveolar mechanics (i.e. the dynamic change in alveolar size and shape with tidal ventilation) we provide a rationale for why the current protective ventilation strategies have not further reduced ARDS mortality. New strategies of protective ventilation based on dynamic physiology in the micro-environment (i.e. alveoli and alveolar ducts) are discussed. Current evidence suggests that alveolar inflation and deflation is viscoelastic in nature, with a fast and slow phase in both alveolar recruitment and collapse. Using this knowledge, a ventilation strategy with a prolonged time at inspiration would recruit alveoli and a brief release time at expiration would prevent alveolar collapse, converting heterogeneous to homogeneous lung inflation significantly reducing ARDS incidence and mortality.
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38
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Kiss T, Silva PL, Huhle R, Moraes L, Santos RS, Felix NS, Santos CL, Morales MM, Capelozzi VL, Kasper M, Pelosi P, Gama de Abreu M, Rocco PRM. Comparison of different degrees of variability in tidal volume to prevent deterioration of respiratory system elastance in experimental acute lung inflammation. Br J Anaesth 2018; 116:708-15. [PMID: 27106975 DOI: 10.1093/bja/aew093] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2015] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Variable ventilation improves respiratory function, but it is not known whether the amount of variability in tidal volume (VT) can be reduced in recruited lungs without a deterioration of respiratory system elastance. METHODS Acute lung inflammation was induced by intratracheal instillation of lipopolysaccharide in 35 Wistar rats. Twenty-eight animals were anaesthetized and ventilated in volume-controlled mode. Lungs were recruited by random variation of VT (mean 6 ml kg(-1), coefficient of variation 30%, normal distribution) for 30 min. Animals were randomly assigned to different amounts of VT variability (n=7 for 90 min per group): 30, 15, 7.5, or 0%. Lung function, diffuse alveolar damage, and gene expression of biological markers associated with cell mechanical stress, inflammation, and fibrogenesis were assessed. Seven animals were not ventilated and served as controls for post-mortem analyses. RESULTS A VT variability of 30%, but not 15, 7.5, or 0%, prevented deterioration of respiratory system elastance [Mean (SD) -7.5 (8.7%), P<0.05; 21.1 (9.6%), P<0.05; 43.3 (25.9), P<0.05; and 41.2 (16.4), P<0.05, respectively]. Diffuse alveolar damage was lower with a VT variability of 30% than with 0% and without ventilation, because of reduced oedema and haemorrhage. A VT variability of 30, 15, or 7.5% reduced the gene expression of amphiregulin, cytokine-induced neutrophil chemoattractant-1, and tumour necrosis factor α compared with a VT variability of 0%. CONCLUSIONS In this model of acute lung inflammation, a VT variability of 30%, compared with 15 and 7.5%, was necessary to avoid deterioration of respiratory system elastance and was not associated with lung histological damage.
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Affiliation(s)
- T Kiss
- Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Therapy, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - P L Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - R Huhle
- Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Therapy, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - L Moraes
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - R S Santos
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - N S Felix
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - C L Santos
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - M M Morales
- Laboratory of Cellular and Molecular Physiology, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - V L Capelozzi
- Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - M Kasper
- Institute of Anatomy, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - P Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, IRCCS AOU San Martino-IST, University of Genoa, Genoa, Italy
| | - M Gama de Abreu
- Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Therapy, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - P R M Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
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Ellwein Fix L, Khoury J, Moores RR, Linkous L, Brandes M, Rozycki HJ. Theoretical open-loop model of respiratory mechanics in the extremely preterm infant. PLoS One 2018; 13:e0198425. [PMID: 29902195 PMCID: PMC6002107 DOI: 10.1371/journal.pone.0198425] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/20/2018] [Indexed: 11/18/2022] Open
Abstract
Non-invasive ventilation is increasingly used for respiratory support in preterm infants, and is associated with a lower risk of chronic lung disease. However, this mode is often not successful in the extremely preterm infant in part due to their markedly increased chest wall compliance that does not provide enough structure against which the forces of inhalation can generate sufficient pressure. To address the continued challenge of studying treatments in this fragile population, we developed a nonlinear lumped-parameter respiratory system mechanics model of the extremely preterm infant that incorporates nonlinear lung and chest wall compliances and lung volume parameters tuned to this population. In particular we developed a novel empirical representation of progressive volume loss based on compensatory alveolar pressure increase resulting from collapsed alveoli. The model demonstrates increased rate of volume loss related to high chest wall compliance, and simulates laryngeal braking for elevation of end-expiratory lung volume and constant positive airway pressure (CPAP). The model predicts that low chest wall compliance (chest stiffening) in addition to laryngeal braking and CPAP enhance breathing and delay lung volume loss. These results motivate future data collection strategies and investigation into treatments for chest wall stiffening.
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Affiliation(s)
- Laura Ellwein Fix
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| | - Joseph Khoury
- Division of Neonatal Medicine, Children’s Hospital of Richmond, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Russell R. Moores
- Division of Neonatal Medicine, Children’s Hospital of Richmond, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Lauren Linkous
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Matthew Brandes
- VCU School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Henry J. Rozycki
- Division of Neonatal Medicine, Children’s Hospital of Richmond, Virginia Commonwealth University, Richmond, Virginia, 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. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 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] [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] [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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Boehme S, Toemboel FPR, Hartmann EK, Bentley AH, Weinheimer O, Yang Y, Achenbach T, Hagmann M, Kaniusas E, Baumgardner JE, Markstaller K. Detection of inspiratory recruitment of atelectasis by automated lung sound analysis as compared to four-dimensional computed tomography in a porcine lung injury model. Crit Care 2018; 22:50. [PMID: 29475456 PMCID: PMC6389194 DOI: 10.1186/s13054-018-1964-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 01/24/2018] [Indexed: 11/21/2022] Open
Abstract
Background Cyclic recruitment and de-recruitment of atelectasis (c-R/D) is a contributor to ventilator-induced lung injury (VILI). Bedside detection of this dynamic process could improve ventilator management. This study investigated the potential of automated lung sound analysis to detect c-R/D as compared to four-dimensional computed tomography (4DCT). Methods In ten piglets (25 ± 2 kg), acoustic measurements from 34 thoracic piezoelectric sensors (Meditron ASA, Norway) were performed, time synchronized to 4DCT scans, at positive end-expiratory pressures of 0, 5, 10, and 15 cmH2O during mechanical ventilation, before and after induction of c-R/D by surfactant washout. 4DCT was post-processed for within-breath variation in atelectatic volume (Δ atelectasis) as a measure of c-R/D. Sound waveforms were evaluated for: 1) dynamic crackle energy (dCE): filtered crackle sounds (600–700 Hz); 2) fast Fourier transform area (FFT area): spectral content above 500 Hz in frequency and above −70 dB in amplitude in proportion to the total amount of sound above −70 dB amplitude; and 3) dynamic spectral coherence (dSC): variation in acoustical homogeneity over time. Parameters were analyzed for global, nondependent, central, and dependent lung areas. Results In healthy lungs, negligible values of Δ atelectasis, dCE, and FFT area occurred. In lavage lung injury, the novel dCE parameter showed the best correlation to Δ atelectasis in dependent lung areas (R2 = 0.88) where c-R/D took place. dCE was superior to FFT area analysis for each lung region examined. The analysis of dSC could predict the lung regions where c-R/D originated. Conclusions c-R/D is associated with the occurrence of fine crackle sounds as demonstrated by dCE analysis. Standardized computer-assisted analysis of dCE and dSC seems to be a promising method for depicting c-R/D. Electronic supplementary material The online version of this article (10.1186/s13054-018-1964-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stefan Boehme
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University Vienna, Waehringer Guertel, 18-20, Vienna, Austria. .,Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany.
| | - Frédéric P R Toemboel
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University Vienna, Waehringer Guertel, 18-20, Vienna, Austria
| | - Erik K Hartmann
- Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Alexander H Bentley
- Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Oliver Weinheimer
- Department of Diagnostic and Interventional Radiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany.,Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Yang Yang
- Department of Diagnostic and Interventional Radiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Tobias Achenbach
- Department of Diagnostic and Interventional Radiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany.,Institute of Diagnostic and Interventional Radiology, St. Vinzenz Hospital, Cologne, Germany
| | - Michael Hagmann
- Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University Vienna, Vienna, Austria
| | - Eugenijus Kaniusas
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
| | - James E Baumgardner
- Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, 15261, USA
| | - Klaus Markstaller
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University Vienna, Waehringer Guertel, 18-20, Vienna, Austria.,Department of Anesthesiology, Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
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43
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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] [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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44
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Bluth T, Teichmann R, Kiss T, Bobek I, Canet J, Cinnella G, De Baerdemaeker L, Gregoretti C, Hedenstierna G, Hemmes SN, Hiesmayr M, Hollmann MW, Jaber S, Laffey JG, Licker MJ, Markstaller K, Matot I, Müller G, Mills GH, Mulier JP, Putensen C, Rossaint R, Schmitt J, Senturk M, Serpa Neto A, Severgnini P, Sprung J, Vidal Melo MF, Wrigge H, Schultz MJ, Pelosi P, Gama de Abreu M. Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial. Trials 2017; 18:202. [DOI: https:/doi.org/10.1186/s13063-017-1929-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2024] Open
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45
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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] [Abstract] [Key Words] [Grants] [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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46
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Cereda M, Xin Y, Hamedani H, Bellani G, Kadlecek S, Clapp J, Guerra L, Meeder N, Rajaei J, Tustison NJ, Gee JC, Kavanagh BP, Rizi RR. Tidal changes on CT and progression of ARDS. Thorax 2017; 72:981-989. [PMID: 28634220 PMCID: PMC5738538 DOI: 10.1136/thoraxjnl-2016-209833] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/13/2017] [Accepted: 05/01/2017] [Indexed: 01/12/2023]
Abstract
BACKGROUND Uncertain prediction of outcome in acute respiratory distress syndrome (ARDS) impedes individual patient management and clinical trial design. OBJECTIVES To develop a radiological metric of injurious inflation derived from matched inspiratory and expiratory CT scans, calibrate it in a model of experimental lung injury, and test it in patients with ARDS. METHODS 73 anaesthetised rats (acid aspiration model) were ventilated (protective or non-protective) for up to 4 hours to generate a spectrum of lung injury. CT was performed (inspiratory and expiratory) at baseline each hour, paired inspiratory and expiratory images were superimposed and voxels tracked in sequential scans. In nine patients with ARDS, paired inspiratory and expiratory CT scans from the first intensive care unit week were analysed. RESULTS In experimental studies, regions of lung with unstable inflation (ie, partial or reversible airspace filling reflecting local strain) were the areas in which subsequent progression of injury was greatest in terms of progressive infiltrates (R=0.77) and impaired compliance (R=0.67, p<0.01). In patients with ARDS, a threshold fraction of tissue with unstable inflation was apparent: >28% in all patients who died and ≤28% in all who survived, whereas segregation of survivors versus non-survivors was not possible based on oxygenation or lung mechanics. CONCLUSIONS A single set of superimposed inspiratory-expiratory CT scans may predict progression of lung injury and outcome in ARDS; if these preliminary results are validated, this could facilitate clinical trial recruitment and individualised care.
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Affiliation(s)
- Maurizio Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Giacomo Bellani
- Department of Emergency and Intensive Care, University of Milan-Bicocca, Monza, Italy
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Justin Clapp
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Luca Guerra
- Department of Nuclear Medicine, University of Milan-Bicocca, Monza, Italy
| | - Natalie Meeder
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jennia Rajaei
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nicholas J Tustison
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Viriginia, USA
| | - James C Gee
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brian P Kavanagh
- Department of Critical Care Medicine, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesia, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Rahim R Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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47
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Lovric G, Mokso R, Arcadu F, Vogiatzis Oikonomidis I, Schittny JC, Roth-Kleiner M, Stampanoni M. Tomographic in vivo microscopy for the study of lung physiology at the alveolar level. Sci Rep 2017; 7:12545. [PMID: 28970505 PMCID: PMC5624921 DOI: 10.1038/s41598-017-12886-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/14/2017] [Indexed: 01/27/2023] Open
Abstract
Lungs represent the essential part of the mammalian respiratory system, which is reflected in the fact that lung failure still is one of the leading causes of morbidity and mortality worldwide. Establishing the connection between macroscopic observations of inspiration and expiration and the processes taking place at the microscopic scale remains crucial to understand fundamental physiological and pathological processes. Here we demonstrate for the first time in vivo synchrotron-based tomographic imaging of lungs with pixel sizes down to a micrometer, enabling first insights into high-resolution lung structure. We report the methodological ability to study lung inflation patterns at the alveolar scale and its potential in resolving still open questions in lung physiology. As a first application, we identified heterogeneous distension patterns at the alveolar level and assessed first comparisons of lungs between the in vivo and immediate post mortem states.
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Affiliation(s)
- Goran Lovric
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland. .,Institute for Biomedical Engineering, ETH Zurich, 8092, Zurich, Switzerland. .,Centre d'Imagerie BioMédicale, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland.
| | - Rajmund Mokso
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.,Max IV Laboratory, Lund University, SE-221 00, Lund, Sweden
| | - Filippo Arcadu
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.,Institute for Biomedical Engineering, ETH Zurich, 8092, Zurich, Switzerland
| | - Ioannis Vogiatzis Oikonomidis
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.,Institute of Anatomy, University of Bern, 3012, Bern, Switzerland
| | | | - Matthias Roth-Kleiner
- Clinic of Neonatology, University Hospital of Lausanne (CHUV), 1011, Lausanne, Switzerland
| | - Marco Stampanoni
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.,Institute for Biomedical Engineering, ETH Zurich, 8092, Zurich, Switzerland
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48
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Lovric G, Vogiatzis Oikonomidis I, Mokso R, Stampanoni M, Roth-Kleiner M, Schittny JC. Automated computer-assisted quantitative analysis of intact murine lungs at the alveolar scale. PLoS One 2017; 12:e0183979. [PMID: 28934236 PMCID: PMC5608210 DOI: 10.1371/journal.pone.0183979] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/15/2017] [Indexed: 12/13/2022] Open
Abstract
Using state-of-the-art X-ray tomographic microscopy we can image lung tissue in three dimensions in intact animals down to a micrometer precision. The structural complexity and hierarchical branching scheme of the lung at this level of details, however, renders the extraction of biologically relevant quantities particularly challenging. We have developed a methodology for a detailed description of lung inflation patterns by measuring the size and the local curvature of the parenchymal airspaces. These quantitative tools for morphological and topological analyses were applied to high-resolution murine 3D lung image data, inflated at different pressure levels under immediate post mortem conditions. We show for the first time direct indications of heterogeneous intra-lobar and inter-lobar distension patterns at the alveolar level. Furthermore, we did not find any indication that a cyclic opening-and-collapse (recruitment) of a large number of alveoli takes place.
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Affiliation(s)
- Goran Lovric
- Centre d’Imagerie BioMédicale, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Ioannis Vogiatzis Oikonomidis
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Rajmund Mokso
- Max IV Laboratory, Lund University, SE-221 00 Lund, Sweden
| | - Marco Stampanoni
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Matthias Roth-Kleiner
- Clinic of Neonatology, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland
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49
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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] [Abstract] [Key Words] [MESH Headings] [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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50
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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] [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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