1
|
Zimmermann R, Roeder F, Ruppert C, Smith BJ, Knudsen L. Low-volume ventilation of preinjured lungs degrades lung function via stress concentration and progressive alveolar collapse. Am J Physiol Lung Cell Mol Physiol 2024; 327:L19-L39. [PMID: 38712429 DOI: 10.1152/ajplung.00323.2023] [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: 10/18/2023] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/08/2024] Open
Abstract
Mechanical ventilation can cause ventilation-induced lung injury (VILI). The concept of stress concentrations suggests that surfactant dysfunction-induced microatelectases might impose injurious stresses on adjacent, open alveoli and function as germinal centers for injury propagation. The aim of the present study was to quantify the histopathological pattern of VILI progression and to test the hypothesis that injury progresses at the interface between microatelectases and ventilated lung parenchyma during low-positive end-expiratory pressure (PEEP) ventilation. Bleomycin was used to induce lung injury with microatelectases in rats. Lungs were then mechanically ventilated for up to 6 h at PEEP = 1 cmH2O and compared with bleomycin-treated group ventilated protectively with PEEP = 5 cmH2O to minimize microatelectases. Lung mechanics were measured during ventilation. Afterward, lungs were fixed at end-inspiration or end-expiration for design-based stereology. Before VILI, bleomycin challenge reduced the number of open alveoli [N(alvair,par)] by 29%. No differences between end-inspiration and end-expiration were observed. Collapsed alveoli clustered in areas with a radius of up to 56 µm. After PEEP = 5 cmH2O ventilation for 6 h, N(alvair,par) remained stable while PEEP = 1 cmH2O ventilation led to an additional loss of aerated alveoli by 26%, mainly due to collapse, with a small fraction partly edema filled. Alveolar loss strongly correlated to worsening of tissue elastance, quasistatic compliance, and inspiratory capacity. The radius of areas of collapsed alveoli increased to 94 µm, suggesting growth of the microatelectases. These data provide evidence that alveoli become unstable in neighborhood of microatelectases, which most likely occurs due to stress concentration-induced local vascular leak and surfactant dysfunction.NEW & NOTEWORTHY Low-volume mechanical ventilation in the presence of high surface tension-induced microatelectases leads to the degradation of lung mechanical function via the progressive loss of alveoli. Microatelectases grow at the interfaces of collapsed and open alveoli. Here, stress concentrations might cause injury and alveolar instability. Accumulation of small amounts of alveolar edema can be found in a fraction of partly collapsed alveoli but, in this model, alveolar flooding is not a major driver for degradation of lung mechanics.
Collapse
Affiliation(s)
- Richard Zimmermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Franziska Roeder
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Clemens Ruppert
- Department of Internal Medicine, Justus-Liebig-University Giessen, Giessen, Germany
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Bradford J Smith
- Department of Bioengineering, College of Engineering, Design & Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado, United States
- Section of Pulmonary and Sleep Medicine, Department of Pediatrics, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, United States
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover, Germany
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Aoyama J, Saito Y, Matsuda K, Tanaka T, Kamio K, Gemma A, Seike M. Increased CTGF expression in alveolar epithelial cells by cyclic mechanical stretch: Its mechanism and the therapeutic effect of pirfenidone. Respir Physiol Neurobiol 2023; 317:104142. [PMID: 37625675 DOI: 10.1016/j.resp.2023.104142] [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: 05/15/2023] [Revised: 08/12/2023] [Accepted: 08/20/2023] [Indexed: 08/27/2023]
Abstract
The mechanisms of fibrosis onset and development remain to be elucidated. However, it has been reported that mechanical stretch promotes fibrosis in various organs and cells, and may be involved in the pathogenesis of pulmonary fibrosis. We demonstrated that ventilator-induced lung hyperextension stimulation in mice increased the expression of connective tissue growth factor (CTGF), a profibrotic cytokine, in lung tissue. Increased CTGF expression induced by cyclic mechanical stretch (CMS) was also observed in vitro using A549 human alveolar epithelial cells. Pathway analysis revealed that the induction of CTGF expression by CMS involved MEK phosphorylation. Furthermore, early growth response 1 (Egr-1) was identified as a transcription factor associated with CTGF expression. Finally, the antifibrotic drug pirfenidone significantly reduced CTGF expression, MEK phosphorylation, and Egr-1 levels induced by CMS. Thus, our results demonstrated that profibrotic cytokine CTGF induced by CMS may be a therapeutic target of pirfenidone.
Collapse
Affiliation(s)
- Junichi Aoyama
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan
| | - Yoshinobu Saito
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan.
| | - Kuniko Matsuda
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan
| | - Toru Tanaka
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan
| | - Koichiro Kamio
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan
| | - Akihiko Gemma
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan
| | - Masahiro Seike
- Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8603 Tokyo, Japan
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Knudsen L, Hummel B, Wrede C, Zimmermann R, Perlman CE, Smith BJ. Acinar micromechanics in health and lung injury: what we have learned from quantitative morphology. Front Physiol 2023; 14:1142221. [PMID: 37025383 PMCID: PMC10070844 DOI: 10.3389/fphys.2023.1142221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/09/2023] [Indexed: 04/08/2023] Open
Abstract
Within the pulmonary acini ventilation and blood perfusion are brought together on a huge surface area separated by a very thin blood-gas barrier of tissue components to allow efficient gas exchange. During ventilation pulmonary acini are cyclically subjected to deformations which become manifest in changes of the dimensions of both alveolar and ductal airspaces as well as the interalveolar septa, composed of a dense capillary network and the delicate tissue layer forming the blood-gas barrier. These ventilation-related changes are referred to as micromechanics. In lung diseases, abnormalities in acinar micromechanics can be linked with injurious stresses and strains acting on the blood-gas barrier. The mechanisms by which interalveolar septa and the blood-gas barrier adapt to an increase in alveolar volume have been suggested to include unfolding, stretching, or changes in shape other than stretching and unfolding. Folding results in the formation of pleats in which alveolar epithelium is not exposed to air and parts of the blood-gas barrier are folded on each other. The opening of a collapsed alveolus (recruitment) can be considered as an extreme variant of septal wall unfolding. Alveolar recruitment can be detected with imaging techniques which achieve light microscopic resolution. Unfolding of pleats and stretching of the blood-gas barrier, however, require electron microscopic resolution to identify the basement membrane. While stretching results in an increase of the area of the basement membrane, unfolding of pleats and shape changes do not. Real time visualization of these processes, however, is currently not possible. In this review we provide an overview of septal wall micromechanics with focus on unfolding/folding as well as stretching. At the same time we provide a state-of-the-art design-based stereology methodology to quantify microarchitecture of alveoli and interalveolar septa based on different imaging techniques and design-based stereology.
Collapse
Affiliation(s)
- Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Centre for Lung Research (DZL), Hannover, Germany
| | - Benjamin Hummel
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Richard Zimmermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Carrie E Perlman
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, United States
| | - Bradford J Smith
- Department of Bioengineering, College of Engineering Design and Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, United States
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| |
Collapse
|
6
|
Mattson CL, Okamura K, Hume PS, Smith BJ. Spatiotemporal distribution of cellular injury and leukocytes during the progression of ventilator-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2022; 323:L281-L296. [PMID: 35700201 PMCID: PMC9423727 DOI: 10.1152/ajplung.00207.2021] [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: 05/12/2021] [Revised: 05/26/2022] [Accepted: 06/12/2022] [Indexed: 11/22/2022] Open
Abstract
Supportive mechanical ventilation is a necessary lifesaving treatment for acute respiratory distress syndrome (ARDS). This intervention often leads to injury exacerbation by ventilator-induced lung injury (VILI). Patterns of injury in ARDS and VILI are recognized to be heterogeneous; however, quantification of these injury distributions remains incomplete. Developing a more detailed understanding of injury heterogeneity, particularly how it varies in space and time, can help elucidate the mechanisms of VILI pathogenesis. Ultimately, this knowledge can be used to develop protective ventilation strategies that slow disease progression. To expand existing knowledge of VILI heterogeneity, we document the spatial evolution of cellular injury distribution and leukocyte infiltration, on the micro- and macroscales, during protective and injurious mechanical ventilation. We ventilated naïve mice using either high inspiratory pressure and zero positive end-expiratory pressure ventilation or low tidal volume with positive end-expiratory pressure. Distributions of cellular injury, identified with propidium iodide staining, were microscopically analyzed at three levels of injury severity. Cellular injury initiated in diffuse, quasi-random patterns, and progressed through expansion of high-density regions of injured cells termed "injury clusters." The density profile of the expanding injury regions suggests that stress shielding occurs, protecting the already injured regions from further damage. Spatial distribution of leukocytes did not correlate with that of cellular injury or ventilation-induced changes in lung function. These results suggest that protective ventilation protocols should protect the interface between healthy and injured regions to stymie injury propagation.
Collapse
Affiliation(s)
- Courtney L Mattson
- Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Kayo Okamura
- Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Patrick S Hume
- Department of Pulmonary, Critical Care, and Sleep Medicine, National Jewish Health, Denver, Colorado
- Department of Pediatrics, Pulmonary and Sleep Medicine, School of Medicine, University of Colorado, Aurora, Colorado
| | - Bradford J Smith
- Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
- Department of Pediatrics, Pulmonary and Sleep Medicine, School of Medicine, University of Colorado, Aurora, Colorado
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Uhl FE, Vanherle L, Meissner A. Cystic fibrosis transmembrane regulator correction attenuates heart failure-induced lung inflammation. Front Immunol 2022; 13:928300. [PMID: 35967318 PMCID: PMC9365932 DOI: 10.3389/fimmu.2022.928300] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/05/2022] [Indexed: 11/13/2022] Open
Abstract
Heart failure (HF) affects 64 million people worldwide. Despite advancements in prevention and therapy, quality of life remains poor for many HF patients due to associated target organ damage. Pulmonary manifestations of HF are well-established. However, difficulties in the treatment of HF patients with chronic lung phenotypes remain as the underlying patho-mechanistic links are still incompletely understood. Here, we aim to investigate the cystic fibrosis transmembrane regulator (CFTR) involvement in lung inflammation during HF, a concept that may provide new mechanism-based therapies for HF patients with pulmonary complications. In a mouse model of HF, pharmacological CFTR corrector therapy (Lumacaftor (Lum)) was applied systemically or lung-specifically for 2 weeks, and the lungs were analyzed using histology, flow cytometry, western blotting, and qPCR. Experimental HF associated with an apparent lung phenotype characterized by vascular inflammation and remodeling, pronounced tissue inflammation as evidenced by infiltration of pro-inflammatory monocytes, and a reduction of pulmonary CFTR+ cells. Moreover, the elevation of a classically-activated phenotype of non-alveolar macrophages coincided with a cell-specific reduction of CFTR expression. Pharmacological correction of CFTR with Lum mitigated the HF-induced downregulation of pulmonary CFTR expression and increased the proportion of CFTR+ cells in the lung. Lum treatment diminished the HF-associated elevation of classically-activated non-alveolar macrophages, while promoting an alternatively-activated macrophage phenotype within the lungs. Collectively, our data suggest that downregulation of CFTR in the HF lung extends to non-alveolar macrophages with consequences for tissue inflammation and vascular structure. Pharmacological CFTR correction possesses the capacity to alleviate HF-associated lung inflammation.
Collapse
Affiliation(s)
- Franziska E. Uhl
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Lotte Vanherle
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Anja Meissner
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
- Department of Physiology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
- *Correspondence: Anja Meissner,
| |
Collapse
|
9
|
Joelsson JP, Ingthorsson S, Kricker J, Gudjonsson T, Karason S. Ventilator-induced lung-injury in mouse models: Is there a trap? Lab Anim Res 2021; 37:30. [PMID: 34715943 PMCID: PMC8554750 DOI: 10.1186/s42826-021-00108-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/20/2021] [Indexed: 12/15/2022] Open
Abstract
Ventilator-induced lung injury (VILI) is a serious acute injury to the lung tissue that can develop during mechanical ventilation of patients. Due to the mechanical strain of ventilation, damage can occur in the bronchiolar and alveolar epithelium resulting in a cascade of events that may be fatal to the patients. Patients requiring mechanical ventilation are often critically ill, which limits the possibility of obtaining patient samples, making VILI research challenging. In vitro models are very important for VILI research, but the complexity of the cellular interactions in multi-organ animals, necessitates in vivo studies where the mouse model is a common choice. However, the settings and duration of ventilation used to create VILI in mice vary greatly, causing uncertainty in interpretation and comparison of results. This review examines approaches to induce VILI in mouse models for the last 10 years, to our best knowledge, summarizing methods and key parameters presented across the studies. The results imply that a more standardized approach is warranted.
Collapse
Affiliation(s)
- Jon Petur Joelsson
- Stem Cell Research Unit, BioMedical Center, School of Health Sciences, University of Iceland, Reykjavik, Iceland. .,Department of Laboratory Hematology, Landspitali-University Hospital, Reykjavik, Iceland. .,EpiEndo Pharmaceuticals, Seltjarnarnes, Iceland.
| | - Saevar Ingthorsson
- Department of Laboratory Hematology, Landspitali-University Hospital, Reykjavik, Iceland.,Faculty of Nursing, University of Iceland, Reykjavik, Iceland
| | | | - Thorarinn Gudjonsson
- Stem Cell Research Unit, BioMedical Center, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Department of Laboratory Hematology, Landspitali-University Hospital, Reykjavik, Iceland.,EpiEndo Pharmaceuticals, Seltjarnarnes, Iceland
| | - Sigurbergur Karason
- Stem Cell Research Unit, BioMedical Center, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Intensive Care Unit, Landspitali-University Hospital, Reykjavik, Iceland
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Gaver DP, Nieman GF, Gatto LA, Cereda M, Habashi NM, Bates JHT. The POOR Get POORer: A Hypothesis for the Pathogenesis of Ventilator-induced Lung Injury. Am J Respir Crit Care Med 2020; 202:1081-1087. [PMID: 33054329 DOI: 10.1164/rccm.202002-0453cp] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Protective ventilation strategies for the injured lung currently revolve around the use of low Vt, ostensibly to avoid volutrauma, together with positive end-expiratory pressure to increase the fraction of open lung and reduce atelectrauma. Protective ventilation is currently applied in a one-size-fits-all manner, and although this practical approach has reduced acute respiratory distress syndrome deaths, mortality is still high and improvements are at a standstill. Furthermore, how to minimize ventilator-induced lung injury (VILI) for any given lung remains controversial and poorly understood. Here we present a hypothesis of VILI pathogenesis that potentially serves as a basis upon which minimally injurious ventilation strategies might be developed. This hypothesis is based on evidence demonstrating that VILI begins in isolated lung regions manifesting a Permeability-Originated Obstruction Response (POOR) in which alveolar leak leads to surfactant dysfunction and increases local tissue stresses. VILI progresses topographically outward from these regions in a POOR-get-POORer fashion unless steps are taken to interrupt it. We propose that interrupting the POOR-get-POORer progression of lung injury relies on two principles: 1) open the lung to minimize the presence of heterogeneity-induced stress concentrators that are focused around the regions of atelectasis, and 2) ventilate in a patient-dependent manner that minimizes the number of lung units that close during each expiration so that they are not forced to rerecruit during the subsequent inspiration. These principles appear to be borne out in both patient and animal studies in which expiration is terminated before derecruitment of lung units has enough time to occur.
Collapse
Affiliation(s)
- Donald P Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana
| | - Gary F Nieman
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York
| | - Louis A Gatto
- Department of Surgery, SUNY Upstate Medical University, Syracuse, New York
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care and.,Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nader M Habashi
- R Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, Maryland; and
| | - Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, Vermont
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Sottile PD, Albers D, Smith BJ, Moss MM. Ventilator dyssynchrony - Detection, pathophysiology, and clinical relevance: A Narrative review. Ann Thorac Med 2020; 15:190-198. [PMID: 33381233 PMCID: PMC7720746 DOI: 10.4103/atm.atm_63_20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/05/2020] [Indexed: 01/21/2023] Open
Abstract
Mortality associated with the acute respiratory distress syndrome remains unacceptably high due in part to ventilator-induced lung injury (VILI). Ventilator dyssynchrony is defined as the inappropriate timing and delivery of a mechanical breath in response to patient effort and may cause VILI. Such deleterious patient–ventilator interactions have recently been termed patient self-inflicted lung injury. This narrative review outlines the detection and frequency of several different types of ventilator dyssynchrony, delineates the different mechanisms by which ventilator dyssynchrony may propagate VILI, and reviews the potential clinical impact of ventilator dyssynchrony. Until recently, identifying ventilator dyssynchrony required the manual interpretation of ventilator pressure and flow waveforms. However, computerized interpretation of ventilator waive forms can detect ventilator dyssynchrony with an area under the receiver operating curve of >0.80. Using such algorithms, ventilator dyssynchrony occurs in 3%–34% of all breaths, depending on the patient population. Moreover, two types of ventilator dyssynchrony, double-triggered and flow-limited breaths, are associated with the more frequent delivery of large tidal volumes >10 mL/kg when compared with synchronous breaths (54% [95% confidence interval (CI), 47%–61%] and 11% [95% CI, 7%–15%]) compared with 0.9% (95% CI, 0.0%–1.9%), suggesting a role in propagating VILI. Finally, a recent study associated frequent dyssynchrony-defined as >10% of all breaths-with an increase in hospital mortality (67 vs. 23%, P = 0.04). However, the clinical significance of ventilator dyssynchrony remains an area of active investigation and more research is needed to guide optimal ventilator dyssynchrony management.
Collapse
Affiliation(s)
- Peter D Sottile
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - David Albers
- Department of Pediatrics, Division of Clinical Informatics, University of Colorado, Aurora, Colorado, USA
| | - Bradford J Smith
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Marc M Moss
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| |
Collapse
|
14
|
Albert K, Krischer JM, Pfaffenroth A, Wilde S, Lopez-Rodriguez E, Braun A, Smith BJ, Knudsen L. Hidden Microatelectases Increase Vulnerability to Ventilation-Induced Lung Injury. Front Physiol 2020; 11:530485. [PMID: 33071807 PMCID: PMC7530907 DOI: 10.3389/fphys.2020.530485] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 08/28/2020] [Indexed: 11/13/2022] Open
Abstract
Mechanical ventilation of lungs suffering from microatelectases may trigger the development of acute lung injury (ALI). Direct lung injury by bleomycin results in surfactant dysfunction and microatelectases at day 1 while tissue elastance and oxygenation remain normal. Computational simulations of alveolar micromechanics 1-day post-bleomycin predict persisting microatelectases throughout the respiratory cycle and increased alveolar strain during low positive end-expiratory pressure (PEEP) ventilation. As such, we hypothesize that mechanical ventilation in presence of microatelectases, which occur at low but not at higher PEEP, aggravates and unmasks ALI in the bleomycin injury model. Rats were randomized and challenged with bleomycin (B) or not (H = healthy). One day after bleomycin instillation the animals were ventilated for 3 h with PEEP 1 (PEEP1) or 5 cmH2O (PEEP5) and a tidal volume of 10 ml/kg bodyweight. Tissue elastance was repetitively measured after a recruitment maneuver to investigate the degree of distal airspace instability. The right lung was subjected to bronchoalveolar lavage (BAL), the left lung was fixed for design-based stereology at light- and electron microscopic level. Prior to mechanical ventilation, lung tissue elastance did not differ. During mechanical ventilation tissue elastance increased in bleomycin-injured lungs ventilated with PEEP = 1 cmH2O but remained stable in all other groups. Measurements at the conclusion of ventilation showed the largest time-dependent increase in tissue elastance after recruitment in B/PEEP1, indicating increased instability of distal airspaces. These lung mechanical findings correlated with BAL measurements including elevated BAL neutrophilic granulocytes as well as BAL protein and albumin in B/PEEP1. Moreover, the increased septal wall thickness and volume of peri-bronchiolar-vascular connective tissue in B/PEEP1 suggested aggravation of interstitial edema by ventilation in presence of microatelectases. At the electron microscopic level, the largest surface area of injured alveolar epithelial was observed in bleomycin-challenged lungs after PEEP = 1 cmH2O ventilation. After bleomycin treatment cellular markers of endoplasmic reticulum stress (p-Perk and p-EIF-2α) were positive within the septal wall and ventilation with PEEP = 1 cmH2O ventilation increased the surface area stained positively for p-EIF-2α. In conclusion, hidden microatelectases are linked with an increased pulmonary vulnerability for mechanical ventilation characterized by an aggravation of epithelial injury.
Collapse
Affiliation(s)
- Karolin Albert
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
| | - Jeanne-Marie Krischer
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
| | - Alexander Pfaffenroth
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
| | - Sabrina Wilde
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hanover, Germany
| | - Elena Lopez-Rodriguez
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hanover, Germany.,Institute for Functional Anatomy, Charité, Berlin, Germany
| | - Armin Braun
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hanover, Germany
| | - Bradford J Smith
- Department of Bioengineering, College of Engineering, Design and Computing, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hanover, Germany
| |
Collapse
|
15
|
High-Frequency Oscillatory Ventilation and Ventilator-Induced Lung Injury: Size Does Matter. Crit Care Med 2020; 48:e66-e73. [PMID: 31634232 DOI: 10.1097/ccm.0000000000004073] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The theoretical basis for minimizing tidal volume during high-frequency oscillatory ventilation may not be appropriate when lung tissue stretch occurs heterogeneously and/or rapidly. The objective of this study was to assess the extent to which increased ventilation heterogeneity may contribute to ventilator-induced lung injury during high-frequency oscillatory ventilation in adults compared with neonates on the basis of lung size, using a computational model of human lungs. DESIGN Computational modeling study. SETTING Research laboratory. SUBJECTS High-fidelity, 3D computational models of human lungs, scaled to various sizes representative of neonates, children, and adults, with varying injury severity. All models were generated from one thoracic CT image of a healthy adult male. INTERVENTIONS Oscillatory ventilation was simulated in each lung model at frequencies ranging from 0.2 to 40 Hz. Sinusoidal flow oscillations were delivered at the airway opening of each model and distributed through the lungs according to regional parenchymal mechanics. MEASUREMENTS AND MAIN RESULTS Acinar flow heterogeneity was assessed by the coefficient of variation in flow magnitudes across all acini in each model. High-frequency oscillatory ventilation simulations demonstrated increasing heterogeneity of regional parenchymal flow with increasing lung size, with decreasing ratio of deadspace to total acinar volume, and with increasing frequency above lung corner frequency and resonant frequency. Potential for resonant amplification was greatest in injured adult-sized lungs with higher regional quality factors indicating the presence of underdamped lung regions. CONCLUSIONS The potential for ventilator-induced lung injury during high-frequency oscillatory ventilation is enhanced at frequencies above lung corner frequency or resonant frequency despite reduced tidal volumes, especially in adults, due to regional amplification of heterogeneous flow. Measurements of corner frequency and resonant frequency should be considered during high-frequency oscillatory ventilation management.
Collapse
|
16
|
Smith BJ, Roy GS, Cleveland A, Mattson C, Okamura K, Charlebois CM, Hamlington KL, Novotny MV, Knudsen L, Ochs M, Hite RD, Bates JHT. Three Alveolar Phenotypes Govern Lung Function in Murine Ventilator-Induced Lung Injury. Front Physiol 2020; 11:660. [PMID: 32695013 PMCID: PMC7338482 DOI: 10.3389/fphys.2020.00660] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 05/25/2020] [Indexed: 01/03/2023] Open
Abstract
Mechanical ventilation is an essential lifesaving therapy in acute respiratory distress syndrome (ARDS) that may cause ventilator-induced lung injury (VILI) through a positive feedback between altered alveolar mechanics, edema, surfactant inactivation, and injury. Although the biophysical forces that cause VILI are well documented, a knowledge gap remains in the quantitative link between altered parenchymal structure (namely alveolar derecruitment and flooding), pulmonary function, and VILI. This information is essential to developing diagnostic criteria and ventilation strategies to reduce VILI and improve ARDS survival. To address this unmet need, we mechanically ventilated mice to cause VILI. Lung structure was measured at three air inflation pressures using design-based stereology, and the mechanical function of the pulmonary system was measured with the forced oscillation technique. Assessment of the pulmonary surfactant included total surfactant, distribution of phospholipid aggregates, and surface tension lowering activity. VILI-induced changes in the surfactant included reduced surface tension lowering activity in the typically functional fraction of large phospholipid aggregates and a significant increase in the pool of surface-inactive small phospholipid aggregates. The dominant alterations in lung structure at low airway pressures were alveolar collapse and flooding. At higher airway pressures, alveolar collapse was mitigated and the flooded alveoli remained filled with proteinaceous edema. The loss of ventilated alveoli resulted in decreased alveolar gas volume and gas-exchange surface area. These data characterize three alveolar phenotypes in murine VILI: flooded and non-recruitable alveoli, unstable alveoli that derecruit at airway pressures below 5 cmH2O, and alveoli with relatively normal structure and function. The fraction of alveoli with each phenotype is reflected in the proportional changes in pulmonary system elastance at positive end expiratory pressures of 0, 3, and 6 cmH2O.
Collapse
Affiliation(s)
- Bradford J Smith
- Department of Bioengineering, College of Engineering, Design & Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, United States
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Gregory S Roy
- Vermont Lung Center, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
| | - Alyx Cleveland
- Vermont Lung Center, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
| | - Courtney Mattson
- Department of Bioengineering, College of Engineering, Design & Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, United States
| | - Kayo Okamura
- Department of Bioengineering, College of Engineering, Design & Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, United States
| | - Chantel M Charlebois
- Vermont Lung Center, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
| | - Katharine L Hamlington
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Michael V Novotny
- Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hanover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hanover, Germany
| | - Matthias Ochs
- Institute of Functional Anatomy, Charité Medical University of Berlin, Berlin, Germany
| | - R Duncan Hite
- Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Jason H T Bates
- Vermont Lung Center, Larner College of Medicine, The University of Vermont, Burlington, VT, United States
| |
Collapse
|
17
|
Abstract
Ventilation-induced lung injury results from mechanical stress and strain that occur during tidal ventilation in the susceptible lung. Classical descriptions of ventilation-induced lung injury have focused on harm from positive pressure ventilation. However, injurious forces also can be generated by patient effort and patient–ventilator interactions. While the role of global mechanics has long been recognized, regional mechanical heterogeneity within the lungs also appears to be an important factor propagating clinically significant lung injury. The resulting clinical phenotype includes worsening lung injury and a systemic inflammatory response that drives extrapulmonary organ failures. Bedside recognition of ventilation-induced lung injury requires a high degree of clinical acuity given its indistinct presentation and lack of definitive diagnostics. Yet the clinical importance of ventilation-induced lung injury is clear. Preventing such biophysical injury remains the most effective management strategy to decrease morbidity and mortality in patients with acute respiratory distress syndrome and likely benefits others at risk.
Collapse
Affiliation(s)
- Purnema Madahar
- Center for Acute Respiratory Failure, Columbia University College of Physicians and Surgeons, New York City, NY, USA.,Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York City, NY, USA.,Department of Medicine, New York-Presbyterian Hospital, New York City, NY, USA
| | - Jeremy R Beitler
- Center for Acute Respiratory Failure, Columbia University College of Physicians and Surgeons, New York City, NY, USA.,Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York City, NY, USA.,Department of Medicine, New York-Presbyterian Hospital, New York City, NY, USA
| |
Collapse
|
18
|
Rühl N, Lopez-Rodriguez E, Albert K, Smith BJ, Weaver TE, Ochs M, Knudsen L. Surfactant Protein B Deficiency Induced High Surface Tension: Relationship between Alveolar Micromechanics, Alveolar Fluid Properties and Alveolar Epithelial Cell Injury. Int J Mol Sci 2019; 20:ijms20174243. [PMID: 31480246 PMCID: PMC6747270 DOI: 10.3390/ijms20174243] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/24/2019] [Accepted: 08/26/2019] [Indexed: 11/16/2022] Open
Abstract
High surface tension at the alveolar air-liquid interface is a typical feature of acute and chronic lung injury. However, the manner in which high surface tension contributes to lung injury is not well understood. This study investigated the relationship between abnormal alveolar micromechanics, alveolar epithelial injury, intra-alveolar fluid properties and remodeling in the conditional surfactant protein B (SP-B) knockout mouse model. Measurements of pulmonary mechanics, broncho-alveolar lavage fluid (BAL), and design-based stereology were performed as a function of time of SP-B deficiency. After one day of SP-B deficiency the volume of alveolar fluid V(alvfluid,par) as well as BAL protein and albumin levels were normal while the surface area of injured alveolar epithelium S(AEinjure,sep) was significantly increased. Alveoli and alveolar surface area could be recruited by increasing the air inflation pressure. Quasi-static pressure-volume loops were characterized by an increased hysteresis while the inspiratory capacity was reduced. After 3 days, an increase in V(alvfluid,par) as well as BAL protein and albumin levels were linked with a failure of both alveolar recruitment and airway pressure-dependent redistribution of alveolar fluid. Over time, V(alvfluid,par) increased exponentially with S(AEinjure,sep). In conclusion, high surface tension induces alveolar epithelial injury prior to edema formation. After passing a threshold, epithelial injury results in vascular leakage and exponential accumulation of alveolar fluid critically hampering alveolar recruitability.
Collapse
Affiliation(s)
- Nina Rühl
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover 30625, Germany
| | - Elena Lopez-Rodriguez
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover 30625, Germany
- Biomedical Research in Endstage and Obstructive Lung Diseases (BREATH), Member of the German Center for Lung Research (DLZ), Hannover 30625, Germany
- REBIRTH, Cluster of Excellence, Hannover 30625, Germany
- Institute of Vegetative Anatomy, Charite, Berlin 10117, Germany
| | - Karolin Albert
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover 30625, Germany
| | - Bradford J Smith
- Department of Bioengineering, University of Colorado Denver, Denver, CO 80045, USA
| | - Timothy E Weaver
- Division of Pulmonary Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45221, USA
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover 30625, Germany
- Biomedical Research in Endstage and Obstructive Lung Diseases (BREATH), Member of the German Center for Lung Research (DLZ), Hannover 30625, Germany
- REBIRTH, Cluster of Excellence, Hannover 30625, Germany
- Institute of Vegetative Anatomy, Charite, Berlin 10117, Germany
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover 30625, Germany.
- Biomedical Research in Endstage and Obstructive Lung Diseases (BREATH), Member of the German Center for Lung Research (DLZ), Hannover 30625, Germany.
- REBIRTH, Cluster of Excellence, Hannover 30625, Germany.
| |
Collapse
|
19
|
Fang M, Fan S, Yao X, Liu N, Gao J, Wang Z, Xu T, Xian X, Li W. Transfection of Sox11 plasmid alleviates ventilator-induced lung injury via Sox11 and FAK. Biochem Biophys Res Commun 2019; 512:182-188. [PMID: 30879763 DOI: 10.1016/j.bbrc.2019.03.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 03/08/2019] [Indexed: 12/15/2022]
Abstract
Background Ventilator-induced lung injury (VILI) is the most common complication in the mechanical ventilation in clinic. The pathogenesis of VILI has not been well understood. The SRY related High Mobility Group box group-F family member 11(Sox11) is a protein associated with lung development. The focal adhesion kinase(FAK) is a cytoplasmic tyrosine kinase and is regulated by Sox11. The present study, therefore, was undertaken to explore the potential role of Sox11 and FAK in VILI. Methods High volume mechanical ventilation(HMV) was used to establish mouse VILI model under anesthesia. The lung injury was evaluated by analyzing the lung weight, bronchoalveolar lavage fluid, histopathological changes and apoptosis of the lung. The Sox11 and FAK expressions in the lung were investigated by real-time qPCR, western blot and immunohistochemistry analysis. Results HMV induced VILI simultaneously companied with decreased expressions of Sox11 and FAK in alveolar epithelial and interstitial cells either in gene and protein levels. Transfection of Sox11 plasmid significantly upregulated expressions of Sox11 and FAK in gene and protein levels in the lung and particularly effectively alleviated VILI. Furthermore, FAK antagonism by PF562271(FAK antagonist) blocked the alleviating effect of Sox11 plasmid transfection on the VILI. Conclusion The dysregulation in the Sox11 and FAK after HMV play an important role in the pathogenesis of VILI, and facilitating the activity of Sox11and FAK might be an effective target and potential option in the prevention and treatment of VILI in clinic.
Collapse
Affiliation(s)
- Mingxing Fang
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China; Department of Intensive Care Medicine, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Shujuan Fan
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
| | - Xiaoguang Yao
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China; College of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, China
| | - Na Liu
- Department of Emergency, The Forth Hospital of Hebei Medical University, Shijiazhuang, China
| | - Junxia Gao
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
| | - Zhiyong Wang
- Department of Intensive Care Medicine, The Third Hospital of Hebei Medical University, Shijiazhuang, China.
| | - Tieling Xu
- Department of Emergency, Hebei General Hospital, Shijiazhuang, China
| | - Xiaohui Xian
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China
| | - Wenbin Li
- Department of Pathophysiology, Neuroscience Research Center, Hebei Medical University, Shijiazhuang, China.
| |
Collapse
|