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Villa B, Erranz B, Cruces P, Retamal J, Hurtado DE. Mechanical and morphological characterization of the emphysematous lung tissue. Acta Biomater 2024; 181:282-296. [PMID: 38705223 DOI: 10.1016/j.actbio.2024.04.039] [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: 07/29/2023] [Revised: 04/22/2024] [Accepted: 04/25/2024] [Indexed: 05/07/2024]
Abstract
Irreversible alveolar airspace enlargement is the main characteristic of pulmonary emphysema, which has been extensively studied using animal models. While the alterations in lung mechanics associated with these morphological changes have been documented in the literature, the study of the mechanical behavior of parenchymal tissue from emphysematous lungs has been poorly investigated. In this work, we characterize the mechanical and morphological properties of lung tissue in elastase-induced emphysema rat models under varying severity conditions. We analyze the non-linear tissue behavior using suitable hyperelastic constitutive models that enable to compare different non-linear responses in terms of hyperelastic material parameters. We further analyze the effect of the elastase dose on alveolar morphology and tissue material parameters and study their connection with respiratory-system mechanical parameters. Our results show that while the lung mechanical function is not significantly influenced by the elastase treatment, the tissue mechanical behavior and alveolar morphology are markedly affected by it. We further show a strong association between alveolar enlargement and tissue softening, not evidenced by respiratory-system compliance. Our findings highlight the importance of understanding tissue mechanics in emphysematous lungs, as changes in tissue properties could detect the early stages of emphysema remodeling. STATEMENT OF SIGNIFICANCE: Gas exchange is vital for life and strongly relies on the mechanical function of the lungs. Pulmonary emphysema is a prevalent respiratory disease where alveolar walls are damaged, causing alveolar enlargement that induces harmful changes in the mechanical response of the lungs. In this work, we study how the mechanical properties of lung tissue change during emphysema. Our results from animal models show that tissue properties are more sensitive to alveolar enlargement due to emphysema than other mechanical properties that describe the function of the whole respiratory system.
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Affiliation(s)
- Benjamín Villa
- Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Vicuña Mackenna 4860, Santiago, Chile; Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
| | - Benjamín Erranz
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
| | - Pablo Cruces
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile. Avenida Repblica 440, Santiago, Chile
| | - Jaime Retamal
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile, Santiago, Chile
| | - Daniel E Hurtado
- Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Vicuña Mackenna 4860, Santiago, Chile; Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile; Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02140, USA.
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Felix NS, Maia LA, Rocha NN, Rodrigues GC, Medeiros M, da Silva LA, Baldavira CM, Fernezlian SDM, Eher EM, Capelozzi VL, Malbrain MLNG, Pelosi P, Rocco PRM, Silva PL. Biological impact of restrictive and liberal fluid strategies at low and high PEEP levels on lung and distal organs in experimental acute respiratory distress syndrome. Front Physiol 2022; 13:992401. [PMID: 36388107 PMCID: PMC9663484 DOI: 10.3389/fphys.2022.992401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/13/2022] [Indexed: 11/28/2022] Open
Abstract
Background: Fluid regimens in acute respiratory distress syndrome (ARDS) are conflicting. The amount of fluid and positive end-expiratory pressure (PEEP) level may interact leading to ventilator-induced lung injury (VILI). We therefore evaluated restrictive and liberal fluid strategies associated with low and high PEEP levels with regard to lung and kidney damage, as well as cardiorespiratory function in endotoxin-induced ARDS. Methods: Thirty male Wistar rats received an intratracheal instillation of Escherichia coli lipopolysaccharide. After 24 h, the animals were anesthetized, protectively ventilated (VT = 6 ml/kg), and randomized to restrictive (5 ml/kg/h) or liberal (40 ml/kg/h) fluid strategies (Ringer lactate). Both groups were then ventilated with PEEP = 3 cmH2O (PEEP3) and PEEP = 9 cmH2O (PEEP9) for 1 h (n = 6/group). Echocardiography, arterial blood gases, and lung mechanics were evaluated throughout the experiments. Histologic analyses were done on the lungs, and molecular biology was assessed in lungs and kidneys using six non-ventilated animals with no fluid therapy. Results: In lungs, the liberal group showed increased transpulmonary plateau pressure compared with the restrictive group (liberal, 23.5 ± 2.9 cmH2O; restrictive, 18.8 ± 2.3 cmH2O, p = 0.046) under PEEP = 9 cmH2O. Gene expression associated with inflammation (interleukin [IL]-6) was higher in the liberal-PEEP9 group than the liberal-PEEP3 group (p = 0.006) and restrictive-PEEP9 (p = 0.012), Regardless of the fluid strategy, lung mechanical power and the heterogeneity index were higher, whereas birefringence for claudin-4 and zonula-ocludens-1 gene expression were lower in the PEEP9 groups. Perivascular edema was higher in liberal groups, regardless of PEEP levels. Markers related to damage to epithelial cells [club cell secreted protein (CC16)] and the extracellular matrix (syndecan) were higher in the liberal-PEEP9 group than the liberal-PEEP3 group (p = 0.010 and p = 0.024, respectively). In kidneys, the expression of IL-6 and neutrophil gelatinase-associated lipocalin was higher in PEEP9 groups, regardless of the fluid strategy. For the liberal strategy, PEEP = 9 cmH2O compared with PEEP = 3 cmH2O reduced the right ventricle systolic volume (37%) and inferior vena cava collapsibility index (45%). Conclusion: The combination of a liberal fluid strategy and high PEEP led to more lung damage. The application of high PEEP, regardless of the fluid strategy, may also be deleterious to kidneys.
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Affiliation(s)
- Nathane S. Felix
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ligia A. Maia
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nazareth N. Rocha
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Rio de Janeiro, Brazil
| | - Gisele C. Rodrigues
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mayck Medeiros
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leticia A. da Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Camila M. Baldavira
- Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | | | - Esmeralda M. Eher
- Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Vera L. Capelozzi
- Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Manu L. N. G. Malbrain
- First Department of Anesthesiology and Intensive Therapy, Medical University of Lublin, Lublin, Poland
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
- San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, Genoa, Italy
| | - Patricia R. M. Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pedro L. Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- *Correspondence: Pedro L. Silva,
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3
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de Carvalho EB, Fonseca ACF, Magalhães R, Pinto EF, Samary CDS, Antunes MA, Baldavira CM, da Silveira LKR, Teodoro WR, de Abreu MG, Capelozzi VL, Felix NS, Pelosi P, Rocco PRM, Silva PL. Effects of different fluid management on lung and kidney during pressure-controlled and pressure-support ventilation in experimental acute lung injury. Physiol Rep 2022; 10:e15429. [PMID: 36065867 PMCID: PMC9446390 DOI: 10.14814/phy2.15429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 07/22/2022] [Accepted: 07/29/2022] [Indexed: 04/24/2023] Open
Abstract
Optimal fluid management is critical during mechanical ventilation to mitigate lung damage. Under normovolemia and protective ventilation, pulmonary tensile stress during pressure-support ventilation (PSV) results in comparable lung protection to compressive stress during pressure-controlled ventilation (PCV) in experimental acute lung injury (ALI). It is not yet known whether tensile stress can lead to comparable protection to compressive stress in ALI under a liberal fluid strategy (LF). A conservative fluid strategy (CF) was compared with LF during PSV and PCV on lungs and kidneys in an established model of ALI. Twenty-eight male Wistar rats received endotoxin intratracheally. After 24 h, they were treated with CF (minimum volume of Ringer's lactate to maintain normovolemia and mean arterial pressure ≥70 mmHg) or LF (~4 times higher than CF) combined with PSV or PCV (VT = 6 ml/kg, PEEP = 3 cmH2 O) for 1 h. Nonventilated animals (n = 4) were used for molecular biology analyses. CF-PSV compared with LF-PSV: (1) decreased the diffuse alveolar damage score (10 [7.8-12] vs. 25 [23-31.5], p = 0.006), mainly due to edema in axial and alveolar parenchyma; (2) increased birefringence for occludin and claudin-4 in lung tissue and expression of zonula-occludens-1 and metalloproteinase-9 in lung. LF compared with CF reduced neutrophil gelatinase-associated lipocalin and interleukin-6 expression in the kidneys in PSV and PCV. In conclusion, CF compared with LF combined with PSV yielded less lung epithelial cell damage in the current model of ALI. However, LF compared with CF resulted in less kidney injury markers, regardless of the ventilatory strategy.
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Affiliation(s)
- Eduardo Butturini de Carvalho
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
- University of VassourasVassourasRJBrazil
| | - Ana Carolina Fernandes Fonseca
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Raquel Ferreira Magalhães
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Eliete Ferreira Pinto
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Cynthia dos Santos Samary
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Mariana Alves Antunes
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | | | | | | | - Marcelo Gama de Abreu
- Pulmonary Engineering Group, Department of Anaesthesiology and Intensive Care Therapy, Technische Universität DresdenUniversity Hospital Carl Gustav CarusDresdenGermany
- Department of Intensive Care and Resuscitation, Anesthesiology InstituteCleveland ClinicClevelandOhioUSA
- Department of Outcomes Research, Anesthesiology InstituteCleveland ClinicClevelandOhioUSA
| | - Vera Luiza Capelozzi
- Department of Pathology, School of MedicineUniversity of São PauloSão PauloBrazil
| | - Nathane Santanna Felix
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated DiagnosticsUniversity of GenoaGenoaItaly
- Anesthesia and Critical Care, San Martino Policlinico HospitalIRCCS for Oncology and NeurosciencesGenoaItaly
| | - Patrícia Rieken Macêdo Rocco
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Institute of Biophysics Carlos Chagas FilhoFederal University of Rio de JaneiroRio de JaneiroRJBrazil
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Oliveira MVD, Magalhães RF, Rocha NN, Fernandes MVS, Antunes MA, Morales MM, Capelozzi VL, Satalin J, Andrews P, Habashi NM, Nieman GF, Rocco PRM, Silva PL. Effects of time-controlled adaptive ventilation on cardiorespiratory parameters and inflammatory response in experimental emphysema. J Appl Physiol (1985) 2022; 132:564-574. [PMID: 34989651 DOI: 10.1152/japplphysiol.00689.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The time-controlled adaptive ventilation (TCAV) method attenuates lung damage in acute respiratory distress syndrome. However, so far, no study has evaluated the impact of the TCAV method on ventilator-induced lung injury (VILI) and cardiac function in emphysema. We hypothesized that the use of the TCAV method to achieve an expiratory flow termination/expiratory peak flow (EFT/EPF) of 25% could reduce VILI and improve right ventricular function in elastase-induced lung emphysema in rats. Five weeks after the last intratracheal instillation of elastase, animals were anesthetized and mechanically ventilated for 1 h using TCAV adjusted to either EFT/EPF 25% or EFT/EPF 75%, the latter often applied in ARDS. Pressure-controlled ventilation (PCV) groups with positive end-expiratory pressure levels similar to positive end-release pressure in TCAV with EFT/EPF 25% and EFT/EPF 75% were also analyzed. Echocardiography and lung ultrasonography were monitored. Lung morphometry, alveolar heterogeneity, and biological markers related to inflammation (interleukin [IL]-6, CINC-1), alveolar pulmonary stretch (amphiregulin), lung matrix damage (metalloproteinase [MMP]-9) were assessed. EFT/EPF 25% reduced respiratory system peak pressure, mean linear intercept, B lines at lung ultrasonography, and increased pulmonary acceleration time/pulmonary ejection time ratio compared with EFT/EPF 75%. The volume fraction of mononuclear cells, neutrophils, and expression of IL-6, CINC-1, amphiregulin, and MMP-9 were lower with EFT/EPF 25% than with EFT/EPF 75%. In conclusion, TCAV with EFT/EPF 25%, compared with EFT/EPF 75%, led to less lung inflammation, hyperinflation, and pulmonary arterial hypertension, which may be a promising strategy for patients with emphysema.
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Affiliation(s)
- Milena Vasconcellos de Oliveira
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel F Magalhães
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nazareth N Rocha
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcos V S Fernandes
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mariana Alves Antunes
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo Marco Morales
- Department of Physiology and Pharmacology, Biomedical Institute, grid.411173.1Fluminense Federal University, Rio de Janeiro, Brazil
| | - Vera Luiza Capelozzi
- Department of Pathology, grid.11899.38University of Sao Paulo, São Paulo, Brazil
| | - Joshua Satalin
- Department of Surgery, grid.411023.5SUNY Upstate Medical University, Syracuse, United States
| | - Penny Andrews
- Department of Surgery, R Adams Cowley Shock Trauma Center, grid.411024.2University of Maryland, Baltimore, Baltimore, United States
| | - Nader M Habashi
- Department of Surgery, Adams Cowley Shock Trauma Center, grid.411024.2University of Maryland, Baltimore, Baltimore, MD, United States
| | - Gary F Nieman
- Department of Surgery, grid.411023.5SUNY Upstate Medical University, Syracuse, New York, United States
| | - Patricia Rieken Macedo Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, grid.8536.8Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
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5
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Xu X, Huang K, Dong F, Qumu S, Zhao Q, Niu H, Ren X, Gu X, Yu T, Pan L, Yang T, Wang C. The Heterogeneity of Inflammatory Response and Emphysema in Chronic Obstructive Pulmonary Disease. Front Physiol 2021; 12:783396. [PMID: 34950055 PMCID: PMC8689000 DOI: 10.3389/fphys.2021.783396] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 11/17/2021] [Indexed: 11/21/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by chronic inflammation, emphysema, airway remodeling, and altered lung function. Despite the canonical classification of COPD as a neutrophilic disease, blood and airway eosinophilia are found in COPD patients. Identifying the tools to assess eosinophilic airway inflammation in COPD models during stable disease and exacerbations will enable the development of novel anti-eosinophilic treatments. We developed different animal models to mimic the pathological features of COPD. Our results show that eosinophils accumulated in the lungs of pancreatic porcine elastase-treated mice, with emphysema arising from the alveolar septa. A lipopolysaccharide challenge significantly increased IL-17 levels and induced a swift change from a type-2 response to an IL-17-driven inflammatory response. However, lipopolysaccharides can exacerbate cigarette smoking-induced airway inflammation dominated by neutrophil infiltration and airway remodeling in COPD models. Our results suggest that eosinophils may be associated with emphysema arising from the alveolar septa, which may be different from the small airway disease-associated emphysema that is dominated by neutrophilic inflammation in cigarette smoke-induced models. The characterization of heterogeneity seen in the COPD-associated inflammatory signature could pave the way for personalized medicine to identify new and effective therapeutic approaches for COPD.
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Affiliation(s)
- Xia Xu
- Department of Immunology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Ke Huang
- Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Fen Dong
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing, China
| | - Shiwei Qumu
- Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Qichao Zhao
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing, China
| | - Hongtao Niu
- Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Xiaoxia Ren
- Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Xiaoying Gu
- Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Tao Yu
- Department of Immunology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Lin Pan
- Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing, China
| | - Ting Yang
- Department of Immunology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Chen Wang
- Department of Immunology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, China
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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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da Cruz DG, de Magalhães RF, Padilha GA, da Silva MC, Braga CL, Silva AR, Gonçalves de Albuquerque CF, Capelozzi VL, Samary CS, Pelosi P, Rocco PRM, Silva PL. Impact of positive biphasic pressure during low and high inspiratory efforts in Pseudomonas aeruginosa-induced pneumonia. PLoS One 2021; 16:e0246891. [PMID: 33577592 PMCID: PMC7880436 DOI: 10.1371/journal.pone.0246891] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 01/28/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND During pneumonia, normal alveolar areas coexist adjacently with consolidated areas, and high inspiratory efforts may predispose to lung damage. To date, no study has evaluated different degrees of effort during Biphasic positive airway pressure (BIVENT) on lung and diaphragm damage in experimental pneumonia, though largely used in clinical setting. We aimed to evaluate lung damage, genes associated with ventilator-induced lung injury (VILI) and diaphragmatic injury, and blood bacteria in pressure-support ventilation (PSV), BIVENT with low and high inspiratory efforts in experimental pneumonia. MATERIAL AND METHODS Twenty-eight male Wistar rats (mean ± SD weight, 333±78g) were submitted Pseudomonas aeruginosa-induced pneumonia. After 24-h, animals were ventilated for 1h in: 1) PSV; 2) BIVENT with low (BIVENTLow-Effort); and 3) BIVENT with high inspiratory effort (BIVENTHigh-Effort). BIVENT was set at Phigh to achieve VT = 6 ml/kg and Plow at 5 cmH2O (n = 7/group). High- and low-effort conditions were obtained through anaesthetic infusion modulation based on neuromuscular drive (P0.1). Lung mechanics, histological damage score, blood bacteria, and expression of genes related to VILI in lung tissue, and inflammation in diaphragm tissue. RESULTS Transpulmonary peak pressure and histological damage score were higher in BIVENTHigh-Effort compared to BIVENTLow-Effort and PSV [16.1 ± 1.9cmH2O vs 12.8 ± 1.5cmH2O and 12.5 ± 1.6cmH2O, p = 0.015, and p = 0.010; median (interquartile range) 11 (9-13) vs 7 (6-9) and 7 (6-9), p = 0.021, and p = 0.029, respectively]. BIVENTHigh-Effort increased interleukin-6 expression compared to BIVENTLow-Effort (p = 0.035) as well as expressions of cytokine-induced neutrophil chemoattractant-1, amphiregulin, and type III procollagen compared to PSV (p = 0.001, p = 0.001, p = 0.004, respectively). Tumour necrosis factor-α expression in diaphragm tissue and blood bacteria were higher in BIVENTHigh-Effort than BIVENTLow-Effort (p = 0.002, p = 0.009, respectively). CONCLUSION BIVENT requires careful control of inspiratory effort to avoid lung and diaphragm damage, as well as blood bacteria. P0.1 might be considered a helpful parameter to optimize inspiratory effort.
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Affiliation(s)
- Daniela G. da Cruz
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel F. de Magalhães
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gisele A. Padilha
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mariana C. da Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cassia L. Braga
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adriana R. Silva
- Laboratory of Immunopharmacology, Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Vera L. Capelozzi
- Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Cynthia S. Samary
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paolo Pelosi
- Anesthesiology and Intensive Care, San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, Genoa, Italy
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
| | - Patricia R. M. Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pedro L. Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
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Dos Santos Rocha A, Südy R, Bizzotto D, Kassai M, Carvalho T, Dellacà RL, Peták F, Habre W. Benefit of Physiologically Variable Over Pressure-Controlled Ventilation in a Model of Chronic Obstructive Pulmonary Disease: A Randomized Study. Front Physiol 2021; 11:625777. [PMID: 33519528 PMCID: PMC7839245 DOI: 10.3389/fphys.2020.625777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/15/2020] [Indexed: 11/25/2022] Open
Abstract
Introduction The advantages of physiologically variable ventilation (PVV) based on a spontaneous breathing pattern have been demonstrated in several respiratory conditions. However, its potential benefits in chronic obstructive pulmonary disease (COPD) have not yet been characterized. We used an experimental model of COPD to compare respiratory function outcomes after 6 h of PVV versus conventional pressure-controlled ventilation (PCV). Materials and Methods Rabbits received nebulized elastase and lipopolysaccharide throughout 4 weeks. After 30 days, animals were anesthetized, tracheotomized, and randomized to receive 6 h of physiologically variable (n = 8) or conventional PCV (n = 7). Blood gases, respiratory mechanics, and chest fluoroscopy were assessed hourly. Results After 6 h of ventilation, animals receiving variable ventilation demonstrated significantly higher oxygenation index (PaO2/FiO2 441 ± 37 (mean ± standard deviation) versus 354 ± 61 mmHg, p < 0.001) and lower respiratory elastance (359 ± 36 versus 463 ± 81 cmH2O/L, p < 0.01) than animals receiving PCV. Animals ventilated with the variable mode also presented less lung derecruitment (decrease in lung aerated area, –3.4 ± 9.9 versus –17.9 ± 6.7%, p < 0.01) and intrapulmonary shunt fraction (9.6 ± 4.1 versus 17.0 ± 5.8%, p < 0.01). Conclusion PVV applied to a model of COPD improved oxygenation, respiratory mechanics, lung aeration, and intrapulmonary shunt fraction compared to conventional ventilation. A reduction in alveolar derecruitment and lung tissue stress leading to better aeration and gas exchange may explain the benefits of PVV.
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Affiliation(s)
- Andre Dos Santos Rocha
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
| | - Roberta Südy
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
| | - Davide Bizzotto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Miklos Kassai
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
| | - Tania Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Raffaele L Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Ferenc Peták
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Walid Habre
- Unit for Anaesthesiological Investigations, Department of Acute Medicine, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
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Abstract
BACKGROUND This study hypothesized that, in experimental mild acute respiratory distress syndrome, lung damage caused by high tidal volume (VT) could be attenuated if VT increased slowly enough to progressively reduce mechanical heterogeneity and to allow the epithelial and endothelial cells, as well as the extracellular matrix of the lung to adapt. For this purpose, different strategies of approaching maximal VT were tested. METHODS Sixty-four Wistar rats received Escherichia coli lipopolysaccharide intratracheally. After 24 h, animals were randomly assigned to receive mechanical ventilation with VT = 6 ml/kg for 2 h (control); VT = 6 ml/kg during hour 1 followed by an abrupt increase to VT = 22 ml/kg during hour 2 (no adaptation time); VT = 6 ml/kg during the first 30 min followed by a gradual VT increase up to 22 ml/kg for 30 min, then constant VT = 22 ml/kg during hour 2 (shorter adaptation time); and a more gradual VT increase, from 6 to 22 ml/kg during hour 1 followed by VT = 22 ml/kg during hour 2 (longer adaptation time). All animals were ventilated with positive end-expiratory pressure of 3 cm H2O. Nonventilated animals were used for molecular biology analysis. RESULTS At 2 h, diffuse alveolar damage score and heterogeneity index were greater in the longer adaptation time group than in the control and shorter adaptation time animals. Gene expression of interleukin-6 favored the shorter (median [interquartile range], 12.4 [9.1-17.8]) adaptation time compared with longer (76.7 [20.8 to 95.4]; P = 0.02) and no adaptation (65.5 [18.1 to 129.4]) time (P = 0.02) strategies. Amphiregulin, metalloproteinase-9, club cell secretory protein-16, and syndecan showed similar behavior. CONCLUSIONS In experimental mild acute respiratory distress syndrome, lung damage in the shorter adaptation time group compared with the no adaptation time group was attenuated in a time-dependent fashion by preemptive adaptation of the alveolar epithelial cells and extracellular matrix. Extending the adaptation period increased cumulative power and did not prevent lung damage, because it may have exposed animals to injurious strain earlier and for a longer time, thereby negating any adaptive benefit.
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Pinto EF, Santos RS, Antunes MA, Maia LA, Padilha GA, de A Machado J, Carvalho ACF, Fernandes MVS, Capelozzi VL, de Abreu MG, Pelosi P, Rocco PRM, Silva PL. Static and Dynamic Transpulmonary Driving Pressures Affect Lung and Diaphragm Injury during Pressure-controlled versus Pressure-support Ventilation in Experimental Mild Lung Injury in Rats. Anesthesiology 2020; 132:307-320. [PMID: 31939846 DOI: 10.1097/aln.0000000000003060] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Pressure-support ventilation may worsen lung damage due to increased dynamic transpulmonary driving pressure. The authors hypothesized that, at the same tidal volume (VT) and dynamic transpulmonary driving pressure, pressure-support and pressure-controlled ventilation would yield comparable lung damage in mild lung injury. METHODS Male Wistar rats received endotoxin intratracheally and, after 24 h, were ventilated in pressure-support mode. Rats were then randomized to 2 h of pressure-controlled ventilation with VT, dynamic transpulmonary driving pressure, dynamic transpulmonary driving pressure, and inspiratory time similar to those of pressure-support ventilation. The primary outcome was the difference in dynamic transpulmonary driving pressure between pressure-support and pressure-controlled ventilation at similar VT; secondary outcomes were lung and diaphragm damage. RESULTS At VT = 6 ml/kg, dynamic transpulmonary driving pressure was higher in pressure-support than pressure-controlled ventilation (12.0 ± 2.2 vs. 8.0 ± 1.8 cm H2O), whereas static transpulmonary driving pressure did not differ (6.7 ± 0.6 vs. 7.0 ± 0.3 cm H2O). Diffuse alveolar damage score and gene expression of markers associated with lung inflammation (interleukin-6), alveolar-stretch (amphiregulin), epithelial cell damage (club cell protein 16), and fibrogenesis (metalloproteinase-9 and type III procollagen), as well as diaphragm inflammation (tumor necrosis factor-α) and proteolysis (muscle RING-finger-1) were comparable between groups. At similar dynamic transpulmonary driving pressure, as well as dynamic transpulmonary driving pressure and inspiratory time, pressure-controlled ventilation increased VT, static transpulmonary driving pressure, diffuse alveolar damage score, and gene expression of markers of lung inflammation, alveolar stretch, fibrogenesis, diaphragm inflammation, and proteolysis compared to pressure-support ventilation. CONCLUSIONS In the mild lung injury model use herein, at the same VT, pressure-support compared to pressure-controlled ventilation did not affect biologic markers. However, pressure-support ventilation was associated with a major difference between static and dynamic transpulmonary driving pressure; when the same dynamic transpulmonary driving pressure and inspiratory time were used for pressure-controlled ventilation, greater lung and diaphragm injury occurred compared to pressure-support ventilation.
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Affiliation(s)
- Eliete F Pinto
- From the Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil (E.F.P., R.S.S., M.A.A., L.A.M., G.A.P., J.D.A.M., A.C.F.C., M.V.S.F., P.R.M.R., P.L.S.) Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil (V.L.C.) Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Therapy, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany (M.G.D.A.) Department of Integrated Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy (P.P.) Institute of Admission and Care of a Scientific Nature, San Martino Policlinico Hospital, Genoa, Italy (P.P.)
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11
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Maia LDA, Fernandes MVS, Santos RS, Agra LC, Carvalho AC, Rocha NDN, Oliveira MV, Santos CL, Morales MM, Capelozzi VL, Souza SAL, Gutfilen B, Schultz MJ, Gama de Abreu M, Pelosi P, Silva PL, Rocco PRM. Effects of Protective Mechanical Ventilation With Different PEEP Levels on Alveolar Damage and Inflammation in a Model of Open Abdominal Surgery: A Randomized Study in Obese Versus Non-obese Rats. Front Physiol 2019; 10:1513. [PMID: 31920717 PMCID: PMC6930834 DOI: 10.3389/fphys.2019.01513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 12/02/2019] [Indexed: 11/22/2022] Open
Abstract
Intraoperative positive end-expiratory pressure (PEEP) has been proposed to restore lung volumes and improve respiratory function in obesity. However, the biological impact of different PEEP levels on the lungs in obesity remains unknown. We aimed to compare the effects of PEEP = 2 cmH2O versus PEEP = 6 cmH2O during ventilation with low tidal volumes on lung function, histology, and biological markers in obese and non-obese rats undergoing open abdominal surgery. Forty-two Wistar rats (21 obese, 21 non-obese) were anesthetized and tracheotomized, and laparotomy was performed with standardized bowel manipulation. Rats were randomly ventilated with protective tidal volume (7 ml/kg) at PEEP = 2 cmH2O or PEEP = 6 cmH2O for 4 h, after which they were euthanized. Lung mechanics and histology, alveolar epithelial cell integrity, and biological markers associated with pulmonary inflammation, alveolar stretch, extracellular matrix, and epithelial and endothelial cell damage were analyzed. In obese rats, PEEP = 6 cmH2O compared with PEEP = 2 cmH2O was associated with less alveolar collapse (p = 0.02). E-cadherin expression was not different between the two PEEP groups. Gene expressions of interleukin (IL)-6 (p = 0.01) and type III procollagen (p = 0.004), as well as protein levels of tumor necrosis factor-alpha (p = 0.016), were lower at PEEP = 6 cmH2O than at PEEP = 2 cmH2O. In non-obese animals, PEEP = 6 cmH2O compared with PEEP = 2 cmH2O led to increased hyperinflation, reduced e-cadherin (p = 0.04), and increased gene expression of IL-6 (p = 0.004) and protein levels of tumor necrosis factor-alpha (p-0.029), but no changes in fibrogenesis. In conclusion, PEEP = 6 cmH2O reduced lung damage and inflammation in an experimental model of mechanical ventilation for open abdominal surgery, but only in obese animals.
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Affiliation(s)
- Lígia de A Maia
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcos V S Fernandes
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel S Santos
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Laís C Agra
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Anna Carolinna Carvalho
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nazareth de N Rocha
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói, Brazil
| | - Milena V Oliveira
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cíntia L Santos
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo M Morales
- Laboratory of Cellular and Molecular Physiology, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vera L Capelozzi
- Department of Pathology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Sergio A L Souza
- Nuclear Medicine Service, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bianca Gutfilen
- Nuclear Medicine Service, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcus J Schultz
- Department of Intensive Care, Laboratory of Experimental Intensive Care and Anesthesiology (L.E.I.C.A.), Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Marcelo Gama de Abreu
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.,San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, Genoa, Italy
| | - Pedro L Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia R M Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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12
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Fodor GH, Bayat S, Albu G, Lin N, Baudat A, Danis J, Peták F, Habre W. Variable Ventilation Is Equally Effective as Conventional Pressure Control Ventilation for Optimizing Lung Function in a Rabbit Model of ARDS. Front Physiol 2019; 10:803. [PMID: 31297064 PMCID: PMC6607923 DOI: 10.3389/fphys.2019.00803] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 06/06/2019] [Indexed: 11/24/2022] Open
Abstract
Background Introducing mathematically derived variability (MVV) into the otherwise monotonous conventional mechanical ventilation has been suggested to improve lung recruitment and gas exchange. Although the application of a ventilation pattern based on variations in physiological breathing (PVV) is beneficial for healthy lungs, its value in the presence of acute respiratory distress syndrome (ARDS) has not been characterized. We therefore aimed at comparing conventional pressure-controlled ventilation with (PCS) or without regular sighs (PCV) to MVV and PVV at two levels of positive end-expiratory pressure (PEEP) in a model of severe ARDS. Methods Anesthetised rabbits (n = 54) were mechanically ventilated and severe ARDS (PaO2/FiO2 ≤ 150 mmHg) was induced by combining whole lung lavage, i.v. endotoxin and injurious ventilation. Rabbits were then randomly assigned to be ventilated with PVV, MVV, PCV, or PCS for 5 h while maintaining either 6 or 9 cmH2O PEEP. Ventilation parameters, blood gas indices and respiratory mechanics (tissue damping, G, and elastance, H) were recorded hourly. Serum cytokine levels were assessed with ELISA and lung histology was analyzed. Results Although no progression of lung injury was observed after 5 h of ventilation at PEEP 6 cmH2O with PVV and PCV, values for G (58.8 ± 71.1[half-width of 95% CI]% and 40.8 ± 39.0%, respectively), H (54.5 ± 57.2%, 50.7 ± 28.3%), partial pressure of carbon-dioxide (PaCO2, 43.9 ± 23.8%, 46.2 ± 35.4%) and pH (−4.6 ± 3.3%, −4.6 ± 2.2%) worsened with PCS and MVV. Regardless of ventilation pattern, application of a higher PEEP improved lung function and precluded progression of lung injury and inflammation. Histology lung injury scores were elevated in all groups with no difference between groups at either PEEP level. Conclusion At moderate PEEP, variable ventilation based on a pre-recorded physiological breathing pattern protected against progression of lung injury equally to the conventional pressure-controlled mode, whereas mathematical variability or application of regular sighs caused worsening in lung mechanics. This outcome may be related to the excessive increases in peak inspiratory pressure with the latter ventilation modes. However, a greater benefit on respiratory mechanics and gas exchange could be obtained by elevating PEEP, compared to the ventilation mode in severe ARDS.
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Affiliation(s)
- Gergely H Fodor
- Unit for Anesthesiological Investigations, Geneva University Hospitals - University of Geneva, Geneva, Switzerland
| | - Sam Bayat
- Unit for Anesthesiological Investigations, Geneva University Hospitals - University of Geneva, Geneva, Switzerland.,Inserm UA7 STROBE Laboratory, Department of Clinical Physiology, Sleep and Exercise, Grenoble University Hospital, Grenoble, France
| | - Gergely Albu
- Unit for Anesthesiological Investigations, Geneva University Hospitals - University of Geneva, Geneva, Switzerland
| | - Na Lin
- Unit for Anesthesiological Investigations, Geneva University Hospitals - University of Geneva, Geneva, Switzerland.,Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Aurélie Baudat
- Unit for Anesthesiological Investigations, Geneva University Hospitals - University of Geneva, Geneva, Switzerland
| | - Judit Danis
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary
| | - Ferenc Peták
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Walid Habre
- Unit for Anesthesiological Investigations, Geneva University Hospitals - University of Geneva, Geneva, Switzerland
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13
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de Oliveira MV, Rocha NDN, Santos RS, Rocco MRM, de Magalhães RF, Silva JD, Souza SAL, Capelozzi VL, Pelosi P, Silva PL, Rocco PRM. Endotoxin-Induced Emphysema Exacerbation: A Novel Model of Chronic Obstructive Pulmonary Disease Exacerbations Causing Cardiopulmonary Impairment and Diaphragm Dysfunction. Front Physiol 2019; 10:664. [PMID: 31191356 PMCID: PMC6546905 DOI: 10.3389/fphys.2019.00664] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 05/09/2019] [Indexed: 12/26/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a progressive disorder of the lung parenchyma which also involves extrapulmonary manifestations, such as cardiovascular impairment, diaphragm dysfunction, and frequent exacerbations. The development of animal models is important to elucidate the pathophysiology of COPD exacerbations and enable analysis of possible therapeutic approaches. We aimed to characterize a model of acute emphysema exacerbation and evaluate its consequences on the lung, heart, and diaphragm. Twenty-four Wistar rats were randomly assigned into one of two groups: control (C) or emphysema (ELA). In ELA group, animals received four intratracheal instillations of pancreatic porcine elastase (PPE) at 1-week intervals. The C group received saline under the same protocol. Five weeks after the last instillation, C and ELA animals received saline (SAL) or E. coli lipopolysaccharide (LPS) (200 μg in 200 μl) intratracheally. Twenty-four hours after saline or endotoxin administration, arterial blood gases, lung inflammation and morphometry, collagen fiber content, and lung mechanics were analyzed. Echocardiography, diaphragm ultrasonography (US), and computed tomography (CT) of the chest were done. ELA-LPS animals, compared to ELA-SAL, exhibited decreased arterial oxygenation; increases in alveolar collapse (p < 0.0001), relative neutrophil counts (p = 0.007), levels of cytokine-induced neutrophil chemoattractant-1, interleukin (IL)-1β, tumor necrosis factor-α, IL-6, and vascular endothelial growth factor in lung tissue, collagen fiber deposition in alveolar septa, airways, and pulmonary vessel walls, and dynamic lung elastance (p < 0.0001); reduced pulmonary acceleration time/ejection time ratio, (an indirect index of pulmonary arterial hypertension); decreased diaphragm thickening fraction and excursion; and areas of emphysema associated with heterogeneous alveolar opacities on chest CT. In conclusion, we developed a model of endotoxin-induced emphysema exacerbation that affected not only the lungs but also the heart and diaphragm, thus resembling several features of human disease. This model of emphysema should allow preclinical testing of novel therapies with potential for translation into clinical practice.
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Affiliation(s)
- Milena Vasconcellos de Oliveira
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nazareth de Novaes Rocha
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói, Brazil
| | - Raquel Souza Santos
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcella Rieken Macedo Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel Ferreira de Magalhães
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Johnatas Dutra Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sergio Augusto Lopes Souza
- Department of Radiology, Faculty of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vera Luiza Capelozzi
- Department of Pathology, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy.,San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, Genoa, Italy
| | - Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia Rieken Macedo Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Treatment with eucalyptol mitigates cigarette smoke-induced lung injury through suppressing ICAM-1 gene expression. Biosci Rep 2018; 38:BSR20171636. [PMID: 29789401 PMCID: PMC6435500 DOI: 10.1042/bsr20171636] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/18/2018] [Accepted: 05/22/2018] [Indexed: 01/12/2023] Open
Abstract
The present study was conducted to investigate the clinical significance of Eucalyptol in treating cigarette smoke-induced lung injury with the potential mechanism involved in the event. Rats were exposed to air (control) and cigarette smoke (smoking) after they were treated with Eucalyptol (260 mg/kg) orally once a day for 12 weeks. Cell counts of bronchoalveolar lavage fluid (BALF), measurements of mean liner intercept (MLI) and mean alveolar number (MAN), and lung function test were executed in experimental animals. Contents of cytokines and intercellular adhesion molecule (ICAM)-1 in BALF and ICAM-1 protein and mRNA expression in lung tissues were determined by ELISA, immunohistochemistry (IHC), and RT-PCR, respectively. A rat model of chronic obstructive pulmonary disease (COPD) displayed declining lung function, increased cell counts and cytokine production in BALF, and emphysema-like lesions in cigarette smoke-exposed lungs compared with the controls (all P<0.01). Treatment with Eucalyptol partly reversed lung function decline with obvious decrease in inflammatory cell infiltrate, TNF-α, IL-6, and ICAM-1 expression levels in the challenged lungs (all P<0.05 and 0.01). Furthermore, oral administration of the drug not only reduced the emphysema-associated lung lesions but also suppressed ICAM-1 protein and mRNA expression in the lungs compared with the control (all P<0.05 or 0.01). Intervention of Eucalyptol mitigates the ongoing inflammatory process in airways and ameliorates the cigarette smoke-induced lung injury through suppressing ICAM-1 gene expression in the diseased lungs.
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