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Slobod D, Damia A, Leali M, Spinelli E, Mauri T. Pathophysiology and Clinical Meaning of Ventilation-Perfusion Mismatch in the Acute Respiratory Distress Syndrome. BIOLOGY 2022; 12:biology12010067. [PMID: 36671759 PMCID: PMC9855693 DOI: 10.3390/biology12010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 01/03/2023]
Abstract
Acute respiratory distress syndrome (ARDS) remains an important clinical challenge with a mortality rate of 35-45%. It is being increasingly demonstrated that the improvement of outcomes requires a tailored, individualized approach to therapy, guided by a detailed understanding of each patient's pathophysiology. In patients with ARDS, disturbances in the physiological matching of alveolar ventilation (V) and pulmonary perfusion (Q) (V/Q mismatch) are a hallmark derangement. The perfusion of collapsed or consolidated lung units gives rise to intrapulmonary shunting and arterial hypoxemia, whereas the ventilation of non-perfused lung zones increases physiological dead-space, which potentially necessitates increased ventilation to avoid hypercapnia. Beyond its impact on gas exchange, V/Q mismatch is a predictor of adverse outcomes in patients with ARDS; more recently, its role in ventilation-induced lung injury and worsening lung edema has been described. Innovations in bedside imaging technologies such as electrical impedance tomography readily allow clinicians to determine the regional distributions of V and Q, as well as the adequacy of their matching, providing new insights into the phenotyping, prognostication, and clinical management of patients with ARDS. The purpose of this review is to discuss the pathophysiology, identification, consequences, and treatment of V/Q mismatch in the setting of ARDS, employing experimental data from clinical and preclinical studies as support.
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Affiliation(s)
- Douglas Slobod
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Critical Care Medicine, McGill University, Montreal, QC H3A 3R1, Canada
| | - Anna Damia
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Marco Leali
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Elena Spinelli
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Tommaso Mauri
- Department of Anesthesia, Critical Care and Emergency, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca’ Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
- Correspondence:
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Different Tidal Volumes May Jeopardize Pulmonary Redox and Inflammatory Status in Healthy Rats Undergoing Mechanical Ventilation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5196896. [PMID: 34745417 PMCID: PMC8570858 DOI: 10.1155/2021/5196896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 10/11/2021] [Indexed: 11/18/2022]
Abstract
Mechanical ventilation (MV) is essential for the treatment of critical patients since it may provide a desired gas exchange. However, MV itself can trigger ventilator-associated lung injury in patients. We hypothesized that the mechanisms of lung injury through redox imbalance might also be associated with pulmonary inflammatory status, which has not been so far described. We tested it by delivering different tidal volumes to normal lungs undergoing MV. Healthy Wistar rats were divided into spontaneously breathing animals (control group, CG), and rats were submitted to MV (controlled ventilation mode) with tidal volumes of 4 mL/kg (MVG4), 8 mL/kg (MVG8), or 12 mL/kg (MVG12), zero end-expiratory pressure (ZEEP), and normoxia (FiO2 = 21%) for 1 hour. After ventilation and euthanasia, arterial blood, bronchoalveolar lavage fluid (BALF), and lungs were collected for subsequent analysis. MVG12 presented lower PaCO2 and bicarbonate content in the arterial blood than CG, MVG4, and MVG8. Neutrophil influx in BALF and MPO activity in lung tissue homogenate were significantly higher in MVG12 than in CG. The levels of CCL5, TNF-α, IL-1, and IL-6 in lung tissue homogenate were higher in MVG12 than in CG and MVG4. In the lung parenchyma, the lipid peroxidation was more important in MVG12 than in CG, MVG4, and MVG8, while there was more protein oxidation in MVG12 than in CG and MVG4. The stereological analysis confirmed the histological pulmonary changes in MVG12. The association of controlled mode ventilation and high tidal volume, without PEEP and normoxia, impaired pulmonary histoarchitecture and triggered redox imbalance and lung inflammation in healthy adult rats.
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Li H, Bersten A, Wiersema U, Schembri D, Cavallaro E, Dixon DL, Bihari S. Bolus intravenous 0.9% saline leads to interstitial permeability pulmonary edema in healthy volunteers. Eur J Appl Physiol 2021; 121:3409-3419. [PMID: 34480632 DOI: 10.1007/s00421-021-04805-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/30/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Bolus intravenous administration of 0.9% saline has been associated with the development of pulmonary edema, and increased mortality. An animal model has previously demonstrated that rapid intravenous administration of 0.9% saline was associated with non-hydrostatic lung injury with increased lung lavage protein. We hypothesized that this non-hydrostatic effect would also occur in human volunteers. METHODS In a randomized, cross-over study of 14 healthy male subjects, the lung lavage protein concentration and cardiorespiratory effects of an intervention with rapid intravenous administration of 30 mL/kg of 0.9% saline were compared with sham intervention. Bronchoalveolar lavage (BAL) was performed after fluid administration. Doppler echocardiography, lung ultrasound, pulmonary function tests, and blood sampling were performed before and after each intervention. RESULTS The BAL total protein concentration was greater after 0.9% saline administration than with sham (196.1 µg/mL (SD 87.6) versus 129.8 µg/mL (SD 55.4), respectively (p = 0.020). Plasma angiopoietin-2 concentration was also increased to 2.26 ng/mL (SD 0.87) after 0.9% saline administration compared with sham 1.53 ng/mL (SD 0.69) (p < 0.001). There were small increases in stroke volume (from 58 mL (IQR 51-74) to 66 mL (IQR 58-74), p = 0.045) and Doppler echocardiography left ventricle E/e' ratio (from 5.0 (IQR 4.5-6.0) to 5.7 (IQR 5.3-6.3), p = 0.007), but no changes to right ventricular function. CONCLUSION Rapid intravenous administration of 0.9% saline leads to interstitial permeability pulmonary edema in healthy human volunteers. Further research is now warranted to understand these effects in critically ill patients.
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Affiliation(s)
- Hanmo Li
- Intensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, SA, 5042, Australia.
| | - Andrew Bersten
- Intensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, SA, 5042, Australia.,Department of Critical Care Medicine, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Ubbo Wiersema
- Intensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - David Schembri
- Respiratory Functions Laboratory, Flinders Medical Centre, Bedford Park, SA, Australia
| | - Elena Cavallaro
- Department of Critical Care Medicine, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Dani-Louise Dixon
- Intensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, SA, 5042, Australia.,Department of Critical Care Medicine, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Shailesh Bihari
- Intensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, SA, 5042, Australia.,Department of Critical Care Medicine, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
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Kitsiouli E, Tenopoulou M, Papadopoulos S, Lekka ME. Phospholipases A2 as biomarkers in ARDS. Biomed J 2021; 44:663-670. [PMID: 34478892 PMCID: PMC8847824 DOI: 10.1016/j.bj.2021.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/16/2021] [Accepted: 08/23/2021] [Indexed: 02/06/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a multifactorial life-threatening lung injury, characterized by diffuse lung inflammation and increased alveolocapillary barrier permeability. The different stages of ARDS have distinctive biochemical and clinical profiles. Despite the progress of our understanding on ARDS pathobiology, the mechanisms underlying its pathogenesis are still obscure. Herein, we review the existing literature about the implications of phospholipases 2 (PLA2s), a large family of enzymes that catalyze the hydrolysis of fatty acids at the sn-2 position of glycerophospholipids, in ARDS-related pathology. We emphasize on the versatile way of participation of different PLA2s isoforms in the distinct ARDS subgroup phenotypes by either potentiating lung inflammation and damage or by preserving the normal lung. Current research supports that PLA2s are associated with the progression and the outcome of ARDS. We herein discuss the transcellular communication of PLA2s through secreted extracellular vesicles and suggest it as a new mechanism of PLA2s involvement in ARDS. Thus, the elucidation of the spatiotemporal features of PLA2s expression may give new insights and provide valuable information about the risk of an individual to develop ARDS or advance to more severe stages, and potentially identify PLA2 isoforms as biomarkers and target for pharmacological intervention.
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Affiliation(s)
- Eirini Kitsiouli
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Margarita Tenopoulou
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Stylianos Papadopoulos
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Marilena E Lekka
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece.
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5
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Papadopoulos S, Kazepidou E, Antonelou MH, Leondaritis G, Tsapinou A, Koulouras VP, Avgeropoulos A, Nakos G, Lekka ME. Secretory Phospholipase A 2-IIA Protein and mRNA Pools in Extracellular Vesicles of Bronchoalveolar Lavage Fluid from Patients with Early Acute Respiratory Distress Syndrome: A New Perception in the Dissemination of Inflammation? Pharmaceuticals (Basel) 2020; 13:ph13110415. [PMID: 33238426 PMCID: PMC7700412 DOI: 10.3390/ph13110415] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 01/08/2023] Open
Abstract
Secretory phospholipase-IIA A2 (sPLA2-IIA) is expressed in a variety of cell types under inflammatory conditions. Its presence in the bronchoalveolar lavage (BAL) fluid of patients with acute respiratory distress syndrome (ARDS) is associated with the severity of the injury. Exosomal type extracellular vesicles, (EVs), are recognized to perform intercellular communication. They may alter the immune status of recipient target cells through cargo shuttling. In this work, we characterized the exosomal type EVs isolated from BAL fluid of patients with early and late ARDS as compared to control/non-ARDS patients, through morphological (confocal and electron microscopy) and biochemical (dynamic light scattering, qRT-PCR, immunoblotting) approaches. We provide evidence for the presence of an sPLA2-IIA-carrying EV pool that coprecipitates with exosomes in the BAL fluid of patients with ARDS. PLA2G2A mRNA was present in all the samples, although more prominently expressed in early ARDS. However, the protein was found only in EVs from early phase ARDS. Under both forms, sPLA2-IIA might be involved in inflammatory responses of recipient lung cells during ARDS. The perception of the association of sPLA2-IIA to the early diagnosis of ARDS or even with a mechanism of development and propagation of lung inflammation can help in the adoption of appropriate and innovative therapeutic strategies.
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Affiliation(s)
- Stylianos Papadopoulos
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece; (S.P.); (E.K.); (A.T.)
| | - Eleftheria Kazepidou
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece; (S.P.); (E.K.); (A.T.)
| | - Marianna H. Antonelou
- Section of Cell Biology & Biophysics, Department of Biology, School of Science, National and Kapodistrian University of Athens (NKUA), Panepistimioupolis, 15784 Athens, Greece;
| | - George Leondaritis
- Laboratory of Pharmacology, School of Medicine, University of Ioannina, 451 10 Ioannina, Greece;
| | - Alexia Tsapinou
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece; (S.P.); (E.K.); (A.T.)
| | - Vasilios P. Koulouras
- Department of Intensive Care Medicine, School of Medicine, University of Ioannina, 451 10 Ioannina, Greece; (V.P.K.); (G.N.)
| | | | - George Nakos
- Department of Intensive Care Medicine, School of Medicine, University of Ioannina, 451 10 Ioannina, Greece; (V.P.K.); (G.N.)
| | - Marilena E. Lekka
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece; (S.P.); (E.K.); (A.T.)
- Correspondence: ; Tel.: +30-6972247374
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da Silva ACL, de Matos NA, de Souza ABF, Castro TDF, Cândido LDS, Oliveira MADGS, Costa GDP, Talvani A, Cangussú SD, Bezerra FS. Sigh maneuver protects healthy lungs during mechanical ventilation in adult Wistar rats. Exp Biol Med (Maywood) 2020; 245:1404-1413. [PMID: 32640895 DOI: 10.1177/1535370220940995] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mechanical ventilation (MV) is a tool used for the treatment of patients with acute or chronic respiratory failure. However, MV is a non-physiological resource, and it can cause metabolic disorders such as release of pro-inflammatory cytokines and production of reactive oxygen species. In clinical setting, maneuvers such as sigh, are used to protect the lungs. Thus, this study aimed to evaluate the effects of sigh on oxidative stress and lung inflammation in healthy adult Wistar rats submitted to MV. Male Wistar rats were divided into four groups: control (CG), mechanical ventilation (MVG), MV set at 20 sighs/h (MVG20), and MV set at 40 sighs/h (MVG40). The MVG, MVG20, and MVG40 were submitted to MV for 1 h. After the protocol, all animals were euthanized and the blood, bronchoalveolar lavage fluid, and lungs were collected for subsequent analysis. In the arterial blood, MVG40 presented higher partial pressure of oxygen and lower partial pressure of carbon dioxide compared to control. The levels of bicarbonate in MVG20 were lower compared to CG. The neutrophil influx in bronchoalveolar lavage fluid was higher in the MVG compared to CG and MVG40. In the lung parenchyma, the lipid peroxidation was higher in MVG compared to CG, MVG20, and MVG40. Superoxide dismutase and catalase activity were higher in MVG compared to CG, MVG20, and MVG40. The levels of IL-1, IL-6, and TNF in the lung homogenate were higher in MVG compared to CG, MVG20, and MVG40. The use of sigh plays a protective role as it reduced redox imbalance and pulmonary inflammation caused by MV.
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Affiliation(s)
- Andréa Cristiane Lopes da Silva
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Natália Alves de Matos
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Ana Beatriz Farias de Souza
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Thalles de Freitas Castro
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Leandro da Silva Cândido
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Michel Angelo das Graças Silva Oliveira
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Guilherme de Paula Costa
- Laboratory of Immunobiology of Inflammation (LABIIN), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - André Talvani
- Laboratory of Immunobiology of Inflammation (LABIIN), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Sílvia Dantas Cangussú
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
| | - Frank Silva Bezerra
- Laboratory of Experimental Pathophysiology (LAFEx), Department of Biological Sciences (DECBI), Institute of Exact and Biological Sciences (ICEB), Federal University of Ouro Preto (UFOP), Ouro Preto, MG 35400-000, Brazil
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7
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Karim HMR, Esquinas AM, Ziatabar S, Insalaco G, Skoczyński S, Šarc I, Ferini-Strambi L, Özyiğit LP, Hernández-Gilsoul T, Singha SK, Ciobanu L, Gutiérrez JLS, Szkulmowski Z, Piervincenzi E, Aguiar M, El-Khatib MF, Corcione N, Kaya AG, Çiledağ A, Kaya A, Valli G, Pierucci P, Resta O, Steiropoulos P, De Marco F, Caldeira V, Mina BA. Continuous Positive Airway Pressure (CPAP) in Non-Apneic Asthma: A Clinical Review of Current Evidence. Turk Thorac J 2020; 21:274-279. [PMID: 32687789 DOI: 10.5152/turkthoracj.2019.19049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/10/2019] [Indexed: 11/22/2022]
Abstract
The use of continuous positive airway pressure (CPAP) in asthma has been a point of debate over the past several years. Various studies, including those on animals and humans have attempted to understand the role and pathophysiology of CPAP in patients with either well controlled or poorly controlled asthma. The aim of this manuscript is to review the currently available literature on the physiologic and clinical effects of CPAP in animal models of asthma and on humans with stable asthma.
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Affiliation(s)
| | - Antonio M Esquinas
- Department of Intensive Care Unit, Hospital General University Morales Meseguer, Murcia, Spain
| | - Sally Ziatabar
- Department of Internal Medicine, Northwell Health - Lenox Hill Hospital, New York, USA
| | - Giuseppe Insalaco
- Institute of Biomedicine and Molecular Immunology, Italian National Research Council, Palermo, Italy
| | - Szymon Skoczyński
- Department of Pulmonology, Medical University of Silesia, Katowice, Poland
| | - Irena Šarc
- Department for Noninvasive Ventilation, University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia
| | | | - Leyla Pur Özyiğit
- Department of Respiratory Medicine, Allergy and Immunology, Koç University Hospital, İstanbul, Turkey
| | | | - Subrata Kumar Singha
- Department of Anesthesiology and Critical Care, All India Institute of Medical Sciences, Raipur, India
| | - Laura Ciobanu
- Department of Internal Medicine and Pulmonology, Clinical Hospital of Rehabilitation Lasi, Lasi, Romania
| | - José Luis Sandoval Gutiérrez
- Department of Pulmonary and Critical Care, Instituto Nacional de Enfermedades Respiratorias, México City, Mexico
| | - Zbigniew Szkulmowski
- Department of Anesthesia and Intensive Care Unit, University Hospital No 1 In Bydgoszcz Collegium Medicum in Bydgoszcz University Nicolaus Copernicus in Torun, Bydgoszcz, Poland
| | - Edoardo Piervincenzi
- Department of Anesthesia and Intensive Carei, Sapienza University of Rome, Rome, Italy
| | - Margarida Aguiar
- Department of Pulmonology, Hospital Beatriz Angelo, Lisbon, Portugal
| | - Mohamad F El-Khatib
- Department of Anesthesiology, American University of Beirut, Beirut, Lebanon
| | - Nadia Corcione
- Department of Anesthesia, Critical Care and Emergency Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Aslıhan Gürün Kaya
- Department of Chest Diseases, Ankara University School of Medicine, Ankara, Turkey
| | - Aydın Çiledağ
- Department of Chest Diseases, Ankara University School of Medicine, Ankara, Turkey
| | - Akın Kaya
- Department of Chest Diseases, Ankara University School of Medicine, Ankara, Turkey
| | - Gabriele Valli
- Department of Emergency Medicine, Azienda Ospedaliera San Giovanni Addolorata, Rome, Italy
| | - Paola Pierucci
- Department of Cardiothoracic, Respiratory and Sleep Medicine, Policlinico University Hospital, Bari, Italy
| | - Onofrio Resta
- Department of Cardiothoracic, Respiratory and Sleep Medicine, Policlinico University Hospital, Bari, Italy
| | | | | | - Vania Caldeira
- Department of Pulmonology, Hospital de Santa Marta-Centro Hospital, Lisboa, Portugal
| | - Bushra A Mina
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Northwell Health - Lenox Hill Hospital, New York, USA
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Schaefer MS, Serpa Neto A, Pelosi P, Gama de Abreu M, Kienbaum P, Schultz MJ, Meyer-Treschan TA. Temporal Changes in Ventilator Settings in Patients With Uninjured Lungs: A Systematic Review. Anesth Analg 2020; 129:129-140. [PMID: 30222649 DOI: 10.1213/ane.0000000000003758] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In patients with uninjured lungs, increasing evidence indicates that tidal volume (VT) reduction improves outcomes in the intensive care unit (ICU) and in the operating room (OR). However, the degree to which this evidence has translated to clinical changes in ventilator settings for patients with uninjured lungs is unknown. To clarify whether ventilator settings have changed, we searched MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science for publications on invasive ventilation in ICUs or ORs, excluding those on patients <18 years of age or those with >25% of patients with acute respiratory distress syndrome (ARDS). Our primary end point was temporal change in VT over time. Secondary end points were changes in maximum airway pressure, mean airway pressure, positive end-expiratory pressure, inspiratory oxygen fraction, development of ARDS (ICU studies only), and postoperative pulmonary complications (OR studies only) determined using correlation analysis and linear regression. We identified 96 ICU and 96 OR studies comprising 130,316 patients from 1975 to 2014 and observed that in the ICU, VT size decreased annually by 0.16 mL/kg (-0.19 to -0.12 mL/kg) (P < .001), while positive end-expiratory pressure increased by an average of 0.1 mbar/y (0.02-0.17 mbar/y) (P = .017). In the OR, VT size decreased by 0.09 mL/kg per year (-0.14 to -0.04 mL/kg per year) (P < .001). The change in VTs leveled off in 1995. Other intraoperative ventilator settings did not change in the study period. Incidences of ARDS (ICU studies) and postoperative pulmonary complications (OR studies) also did not change over time. We found that, during a 39-year period, from 1975 to 2014, VTs in clinical studies on mechanical ventilation have decreased significantly in the ICU and in the OR.
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Affiliation(s)
- Maximilian S Schaefer
- From the Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Ary Serpa Neto
- Department of Critical Care Medicine, Hospital Israelita Albert Einstein, São Paulo, Brazil.,Program of Post-Graduation, Innovation and Research, Faculdade de Medicina do ABC, Santo Andre, Brazil
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, San Martino Policlinico Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) for Oncology, Genoa, Italy
| | - Marcelo Gama de Abreu
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Peter Kienbaum
- From the Department of Anesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany
| | - Marcus J Schultz
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, the Netherlands
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9
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Abstract
PURPOSE OF REVIEW ARDS is a severe pulmonary disease characterized by inflammation. However, inflammation-directed therapies have yet failed to improve the outcome in ARDS patients. One of the reasons may be the underestimated complexity of inflammation. Here, we summarize recent insights into the complex interrelations between inflammatory circuits. RECENT FINDINGS Gene expression analysis from animal models or from patients with ARDS, sepsis or trauma show an enormous number of differentially expressed genes with highly significant overlaps between the various conditions. These similarities, however, should not obscure the complexity of inflammation. We suggest to consider inflammation in ARDS as a system controlled by scale-free networks of genome-wide molecular interaction with hubs (e.g. NFκB, C/EBPβ, ATF3), exhibiting nonlinear emergence and the ability to adapt, meaning for instance that mild and life-threatening inflammation in ARDS are distinct processes. In order to comprehend this complex system, it seems necessary to combine model-driven simulations, data-driven modelling and hypothesis-driven experimental studies. Recent experimental studies have illustrated how several regulatory circuits interact during pulmonary inflammation, including the resolution of inflammation, the inflammasome, autophagy and apoptosis. SUMMARY We suggest that therapeutic interventions in ARDS should be based on a systems approach to inflammation.
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Abstract
Fifty years after the first description of acute respiratory distress syndrome (ARDS), none of the many positive drug studies in animal models have been confirmed in clinical trials and translated into clinical practice. This bleak outcome of so many animal experiments shows how difficult it is to model ARDS. Lungs from patients are characterized by hyperinflammation, permeability edema, and hypoxemia; accordingly, this is what most models aim to reproduce. However, in animal models it is very easy to cause inflammation in the lungs, but difficult to cause hypoxemia. Often - and not unlike in patients - models with hypoxemia are accompanied by cardiovascular failure that necessitates fluid support and ventilation, raising the question as to the role of intensive care measures in models of ARDS. In our opinion, there are two major arguments in favor of modelling intensive care medicine in models of ARDS: (1) preventing death from shock; and (2) modelling ventilation and other ICU measures as a second hit. The preferable predictive endpoints in any model of ARDS remain unclear. At present, the best recommendation is to use endpoints that can be compared across studies (i.e. PaO2/FiO2 ratio, compliance, wet-to-dry weight ratio) rather than percentage data. Another important and often overlooked issue is the fact that the thermoneutral environmental temperatures for mice and rats are 30℃ and 28℃, respectively; thus, at room temperature (20-22℃) they suffer from cold stress with the associated significant metabolic changes. While, by definition, any model is an abstraction, we suggest that clinically relevant models of ARDS will have to closer recapitulate important properties of the disease while taking into account species-specific confounders.
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Affiliation(s)
- Stefan Uhlig
- 1 Institute of Pharmacology and Toxicology, RWTH Aachen University, Aachen, Germany
| | - Wolfgang M Kuebler
- 2 72126 Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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11
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One-hit Models of Ventilator-induced Lung Injury: Benign Inflammation versus Inflammation as a By-product. Anesthesiology 2017; 126:909-922. [PMID: 28277372 DOI: 10.1097/aln.0000000000001605] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND One important explanation for the detrimental effects of conventional mechanical ventilation is the biotrauma hypothesis that ventilation may trigger proinflammatory responses that subsequently cause lung injury. This hypothesis has frequently been studied in so-called one-hit models (overventilation of healthy lungs) that so far have failed to establish an unequivocal link between inflammation and hypoxemic lung failure. This study was designed to develop a one-hit biotrauma model. METHODS Mice (six per group) were ventilated for up to 7 h (positive end-expiratory pressure 2 cm H2O) and received 300 μl/h fluid support. Series_1: initial plateau pressures of 10, 24, 27, or 30 cm H2O. Series_2: ventilation with pressure release at 34 cm H2O and initial plateau pressure of 10, 24, 27, or 30 cm H2O. To study the significance of inflammation, the latter groups were also pretreated with the steroid dexamethasone. RESULTS Within 7 h, 20 of 24 mice ventilated with plateau pressure of 27 cm H2O or more died of a catastrophic lung failure characterized by strongly increased proinflammatory markers and a precipitous decrease in pulmonary compliance, blood pressure, and oxygenation. Pretreatment with dexamethasone reduced inflammation, but prolonged median survival time by 30 min. CONCLUSIONS Our findings demonstrate a sharp distinction between ventilation with 24 cm H2O that was well tolerated and ventilation with 27 cm H2O that was lethal for most animals due to catastrophic lung failure. In the former case, inflammation was benign and in the latter, a by-product that only accelerated lung failure. The authors suggest that biotrauma-when defined as a ventilation-induced and inflammation-dependent hypoxemia-is difficult to study in murine one-hit models of ventilation, at least not within 7 h. (Anesthesiology 2017; 126:909-22).
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El-Badrawy MK, Ali REM, Yassen AM, Elela MAA, Elmorsey RA. Delayed-onset chest infections in liver transplant recipients: a prospective study. THE EGYPTIAN JOURNAL OF BRONCHOLOGY 2016. [DOI: 10.4103/1687-8426.184362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Long-term home noninvasive mechanical ventilation increases systemic inflammatory response in chronic obstructive pulmonary disease: a prospective observational study. Mediators Inflamm 2014; 2014:503145. [PMID: 24976687 PMCID: PMC4058212 DOI: 10.1155/2014/503145] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/08/2014] [Accepted: 05/11/2014] [Indexed: 02/05/2023] Open
Abstract
Background. Long-term home noninvasive mechanical ventilation (NIV) is beneficial in COPD but its impact on inflammation is unknown. We assessed the hypothesis that NIV modulates systemic and pulmonary inflammatory biomarkers in stable COPD. Methods. Among 610 patients referred for NIV, we shortlisted those undergoing NIV versus oxygen therapy alone, excluding subjects with comorbidities or non-COPD conditions. Sputum and blood samples were collected after 3 months of clinical stability and analyzed for levels of human neutrophil peptides (HNP), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha). Patients underwent a two-year follow-up. Unadjusted, propensity-matched, and pH-stratified analyses were performed. Results. Ninety-three patients were included (48 NIV, 45 oxygen), with analogous baseline features. Sputum analysis showed similar HNP, IL-6, IL-10, and TNF-alpha levels (P > 0.5). Conversely, NIV group exhibited higher HNP and IL-6 systemic levels (P < 0.001) and lower IL-10 concentrations (P < 0.001). Subjects undergoing NIV had a significant reduction of rehospitalizations during follow-up compared to oxygen group (P = 0.005). These findings were confirmed after propensity matching and pH stratification. Conclusions. These findings challenge prior paradigms based on the assumption that pulmonary inflammation is per se detrimental. NIV beneficial impact on lung mechanics may overcome the potential unfavorable effects of an increased inflammatory state.
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Nalayanda DD, Fulton WB, Wang TH, Abdullah F. A multiphase fluidic platform for studying ventilator-induced injury of the pulmonary epithelial barrier. Integr Biol (Camb) 2014; 5:1141-8. [PMID: 23835753 DOI: 10.1039/c3ib40037a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mechanical ventilation has been a critical part of basic life support for many years, with almost one-third of all patients in the intensive care unit requiring the aid. However studies over the past two decades have indicated that ventilators have the potential to cause or aggravate pulmonary injury. The lung with its anatomically complex architecture and unique amalgam of cell types and interfaces is very difficult to replicate in vitro. This study is focused on mimicking the distal unit of the alveolus in developing an analytical platform for evaluating cellular interactions and response to mechanostimulation. The prototype developed incorporates the ability to expose alveolar cells to sustained periods of supra-physiological pressure when cultured at an air-liquid interface with constant air-flow on the apical side and medium replenishment on basolateral surfaces. The in vitro evaluation of the alveolar, A549 and H441, cells indicated disruption of the cell layer integrity in response to sustained pressure application. The results indicate a magnitude- and duration-dependent response among both the cell types.
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Abstract
This article describes the gas exchange abnormalities occurring in the acute respiratory distress syndrome seen in adults and children and in the respiratory distress syndrome that occurs in neonates. Evidence is presented indicating that the major gas exchange abnormality accounting for the hypoxemia in both conditions is shunt, and that approximately 50% of patients also have lungs regions in which low ventilation-to-perfusion ratios contribute to the venous admixture. The various mechanisms by which hypercarbia may develop and by which positive end-expiratory pressure improves gas exchange are reviewed, as are the effects of vascular tone and airway narrowing. The mechanisms by which surfactant abnormalities occur in the two conditions are described, as are the histological findings that have been associated with shunt and low ventilation-to-perfusion.
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Affiliation(s)
- Richard K Albert
- Chief of Medicine, Denver Health, Professor of Medicine, University of Colorado, Adjunct Professor of Engineering and Computer Science, University of Denver, Denver, Colorado, USA.
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Abstract
Mechanical ventilation (MV) is, by definition, the application of external forces to the lungs. Depending on their magnitude, these forces can cause a continuum of pathophysiological alterations ranging from the stimulation of inflammation to the disruption of cell-cell contacts and cell membranes. These side effects of MV are particularly relevant for patients with inhomogeneously injured lungs such as in acute lung injury (ALI). These patients require supraphysiological ventilation pressures to guarantee even the most modest gas exchange. In this situation, ventilation causes additional strain by overdistension of the yet non-injured region, and additional stress that forms because of the interdependence between intact and atelectatic areas. Cells are equipped with elaborate mechanotransduction machineries that respond to strain and stress by the activation of inflammation and repair mechanisms. Inflammation is the fundamental response of the host to external assaults, be they of mechanical or of microbial origin and can, if excessive, injure the parenchymal tissue leading to ALI. Here, we will discuss the forces generated by MV and how they may injure the lungs mechanically and through inflammation. We will give an overview of the mechanotransduction and how it leads to inflammation and review studies demonstrating that ventilator-induced lung injury can be prevented by blocking pathways of mechanotransduction or inflammation.
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Affiliation(s)
- Ulrike Uhlig
- Department of Pharmacology & Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Abstract
Optimal management of the acute respiratory distress syndrome (ARDS) requires prompt recognition, treatment of the underlying cause and the prevention of secondary injury. Ventilator-associated lung injury (VALI) is one of the several iatrogenic factors that can exacerbate lung injury and ARDS. Reduction of VALI by protective low tidal volume ventilation is one of the only interventions with a proven survival benefit in ARDS. There are, however, several factors inhibiting the widespread use of this technique in patients with established lung injury. Prevention of ARDS and VALI by detecting at-risk patients and implementing protective ventilation early is a feasible strategy. Detection of injurious ventilation itself is possible, and potential biological markers of VALI have been investigated. Finally, facilitation of protective ventilation, including techniques such as extracorporeal support, can mitigate VALI.
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Affiliation(s)
- David Salman
- Adult Intensive Care Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, United Kingdom
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Zhang LN, Sun JP, Xue XY, Wang JX. Exogenous pulmonary surfactant for acute respiratory distress syndrome in adults: A systematic review and meta-analysis. Exp Ther Med 2012; 5:237-242. [PMID: 23251275 PMCID: PMC3524286 DOI: 10.3892/etm.2012.746] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 10/10/2012] [Indexed: 01/11/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is often characterized by reduced lung compliance, which suggests dysfunction of the endogenous surfactant system. The effectiveness of exogenous surfactants as replacements for the endogenous system in the treatment of ARDS in adults was assessed. Randomized controlled trials from Medline (1950–2011), Embase (1989–2011), the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (1994–2011) were analyzed. Two reviewers identified trials for inclusion and the results of included trials were quantitatively pooled with a fixed-effects model. Seven trials (2,144 patients) with good methodological quality were included in the analysis. Pulmonary surfactant treatment was not associated with reduced mortality [relative risk (RR), 1.00; 95% confidence interval (CI) 0.89–1.12]. Subgroup analysis revealed no reduced mortality for various surfactant types. Heterogeneity was not significant in the primary outcome analysis (I2=0%). There was no evidence of publication bias. Oxygenation, ventilation-free days, duration of ventilation and APACHE II scores did not undergo pooled analysis due to insufficient data. Exogenous surfactant did not reduce mortality in adults with ARDS in our meta-analysis, and we cannot accurately define whether exogenous surfactant has an effect on oxygenation from the included studies.
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Affiliation(s)
- Li-Na Zhang
- Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, P.R. China
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Michelotto PV, Muehlmann LA, Zanatta AL, Bieberbach EWR, Kryczyk M, Fernandes LC, Nishiyama A. Pulmonary inflammation due to exercise-induced pulmonary haemorrhage in Thoroughbred colts during race training. Vet J 2012; 190:e3-e6. [PMID: 22108190 DOI: 10.1016/j.tvjl.2010.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 08/11/2010] [Accepted: 08/24/2010] [Indexed: 10/15/2022]
Abstract
This study investigated the putative roles of inflammation and platelet-activating factor (PAF) in exercise-induced pulmonary haemorrhage (EIPH). Two-year-old Thoroughbred colts (n=37) were exercised on a racetrack for 5months before commencement of the study. Each colt was then exercised at 15-16m/s over 800-1000m and broncho-alveolar lavage fluid (BALF) was collected 24h later. The colts were subsequently divided into two groups on the basis of BALF analysis; an EIPH-positive group (presence of haemosiderophages, n=23) and an EIPH-negative group (absence of haemosiderophages, n=14). BALF from the EIPH-positive group had a significantly higher protein concentration (0.39±0.28 vs. 0.19±0.12mg/mL, P=0.031), higher PAF bioactivity (0.18±0.12 vs. 0.043±0.05 340:380nm ratio, P=0.042) and a higher lipid hydroperoxide concentration compared to the EIPH-negative group. There was also a lower nitrite concentration and reduced production of superoxide anion and hydrogen peroxide by alveolar macrophages in the EIPH-positive group. There was evidence of pulmonary inflammation and a decreased innate immune response of alveolar macrophages in EIPH-positive colts compared with the EIPH-negative group.
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Affiliation(s)
- Pedro V Michelotto
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil; Department of Agricultural and Environmental Sciences, Pontifícia Universidade Católica do Paraná, São José dos Pinhais, PR 80242-980, Brazil.
| | - Luis A Muehlmann
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil
| | - Ana L Zanatta
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil
| | - Eloyse W R Bieberbach
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil
| | - Marcelo Kryczyk
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil
| | - Luis C Fernandes
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil
| | - Anita Nishiyama
- Laboratory of Cellular Metabolism, Department of Physiology, Universidade Federal do Paraná, Curitiba, PR 81530-000, Brazil
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CRITICAL CARE. Br J Anaesth 2012. [DOI: 10.1093/bja/aer477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Reiss LK, Kowallik A, Uhlig S. Recurrent recruitment manoeuvres improve lung mechanics and minimize lung injury during mechanical ventilation of healthy mice. PLoS One 2011; 6:e24527. [PMID: 21935418 PMCID: PMC3174196 DOI: 10.1371/journal.pone.0024527] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 08/12/2011] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Mechanical ventilation (MV) of mice is increasingly required in experimental studies, but the conditions that allow stable ventilation of mice over several hours have not yet been fully defined. In addition, most previous studies documented vital parameters and lung mechanics only incompletely. The aim of the present study was to establish experimental conditions that keep these parameters within their physiological range over a period of 6 h. For this purpose, we also examined the effects of frequent short recruitment manoeuvres (RM) in healthy mice. METHODS Mice were ventilated at low tidal volume V(T) = 8 mL/kg or high tidal volume V(T) = 16 mL/kg and a positive end-expiratory pressure (PEEP) of 2 or 6 cm H(2)O. RM were performed every 5 min, 60 min or not at all. Lung mechanics were followed by the forced oscillation technique. Blood pressure (BP), electrocardiogram (ECG), heart frequency (HF), oxygen saturation and body temperature were monitored. Blood gases, neutrophil-recruitment, microvascular permeability and pro-inflammatory cytokines in bronchoalveolar lavage (BAL) and blood serum as well as histopathology of the lung were examined. RESULTS MV with repetitive RM every 5 min resulted in stable respiratory mechanics. Ventilation without RM worsened lung mechanics due to alveolar collapse, leading to impaired gas exchange. HF and BP were affected by anaesthesia, but not by ventilation. Microvascular permeability was highest in atelectatic lungs, whereas neutrophil-recruitment and structural changes were strongest in lungs ventilated with high tidal volume. The cytokines IL-6 and KC, but neither TNF nor IP-10, were elevated in the BAL and serum of all ventilated mice and were reduced by recurrent RM. Lung mechanics, oxygenation and pulmonary inflammation were improved by increased PEEP. CONCLUSIONS Recurrent RM maintain lung mechanics in their physiological range during low tidal volume ventilation of healthy mice by preventing atelectasis and reduce the development of pulmonary inflammation.
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Affiliation(s)
- Lucy Kathleen Reiss
- Institute of Pharmacology and Toxicology, Medical Faculty of RWTH Aachen University, Aachen, Germany.
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Kalimeris K, Christodoulaki K, Karakitsos P, Batistatou A, Lekka M, Bai M, Kitsiouli E, Nakos G, Kostopanagiotou G. Influence of propofol and volatile anaesthetics on the inflammatory response in the ventilated lung. Acta Anaesthesiol Scand 2011; 55:740-8. [PMID: 21615348 DOI: 10.1111/j.1399-6576.2011.02461.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND The immunomodulatory effects of volatile anaesthetics in vitro and the protective effect of propofol in lung injury spurred us to study the effects of volatile anaesthetics and propofol on lung tissue in vivo. METHODS Twenty-seven pigs were randomized to 4-h general anaesthesia with propofol (8 mg/kg/h, group P, n=9), sevoflurane [minimum alveolar concentration (MAC)=1.0, group S, n=9) or desflurane (MAC=1.0, group D, n=9). Four healthy animals served as the no-ventilation group. Bronchoalveolar lavage fluid (BALF) was obtained to measure the cell counts, platelet-activating factor acetylhydrolase (PAF-AcH), phospholipase A(2) (PLA(2)) and superoxide dismutase (SOD) activity. Lung tissues were evaluated histologically and for caspase-3 expression. RESULTS Volatile anaesthetics reduced PAF-AcH levels without affecting PLA(2) activity and resulted in decreased alveolar macrophage and increased lymphocyte counts in BALF (sevoflurane: 29 ± 23%; desflurane: 26 ± 6%, both P<0.05 compared with 4 ± 2% in the no-ventilation group). These findings were accompanied by atelectasis and inflammatory cells' infiltration in the inhalational anaesthetics groups. Also, sevoflurane reduced SOD activity and both sevoflurane and desflurane induced significant caspase-3 expression. In contrast, propofol resulted in a minor degree of inflammation and preserved BALF cells' composition without triggering apoptosis. CONCLUSION Halogenated anaesthetics seem to trigger an immune lymphocytic response in the lung, inducing significant apoptosis and impairment of PAF-AcH. In contrast, propofol preserves anti-inflammatory and anti-oxidant defences during mechanical ventilation, thus preventing the emergence of apoptosis.
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Affiliation(s)
- K Kalimeris
- 2nd Department of Anaesthesiology, Medical School, University of Athens, Attikon Hospital, Greece.
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Letsiou E, Kitsiouli E, Nakos G, Lekka ME. Mild stretch activates cPLA2 in alveolar type II epithelial cells independently through the MEK/ERK and PI3K pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1811:370-6. [PMID: 21185392 DOI: 10.1016/j.bbalip.2010.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 12/15/2010] [Accepted: 12/16/2010] [Indexed: 10/18/2022]
Abstract
Alveolar epithelial type II cells (AT II) in which lung surfactant synthesis and secretion take place, are subjected to low magnitude stretch during normal breathing. The aim of the study was to explore the effect of mild stretch on phospholipase A(2) (PLA(2)) activation, an enzyme known to be involved in surfactant secretion. In A549 cells (a model of AT II cells), we showed, using a fluorometric assay, that stretch triggers an increase of total PLA(2) activity. Western blot experiments revealed that the cytosolic isoform cPLA(2) is rapidly phosphorylated under stretch, in addition to a modest increase in cPLA(2) mRNA levels. Treatment of A549 cells with selective inhibitors of the MEK/ERK pathway significantly attenuated the stretch-induced cPLA(2) phosphorylation. A strong interaction of cPLA(2) and pERK enzymes was demonstrated by immunoprecipitation. We also found that inhibition of PI3K pathway attenuated cPLA(2) activation after stretch, without affecting pERK levels. Our results suggest that low magnitude stretch can induce cPLA(2) phosphorylation through the MEK/ERK and PI3K-Akt pathways, independently.
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Affiliation(s)
- Eleftheria Letsiou
- Biochemistry Laboratory, Chemistry Department, University of Ioannina, 45110, Ioannina, Greece
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Papiris SA, Manali ED, Kolilekas L, Kagouridis K, Triantafillidou C, Tsangaris I, Roussos C. Clinical review: idiopathic pulmonary fibrosis acute exacerbations--unravelling Ariadne's thread. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:246. [PMID: 21235829 PMCID: PMC3220036 DOI: 10.1186/cc9241] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a dreadful, chronic, and irreversibly progressive fibrosing disease leading to death in all patients affected, and IPF acute exacerbations constitute the most devastating complication during its clinical course. IPF exacerbations are subacute/acute, clinically significant deteriorations of unidentifiable cause that usually transform the slow and more or less steady disease decline to the unexpected appearance of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) ending in death. The histological picture is that of diffuse alveolar damage (DAD), which is the tissue counterpart of ARDS, upon usual interstitial pneumonia, which is the tissue equivalent of IPF. ALI/ARDS and acute interstitial pneumonia share with IPF exacerbations the tissue damage pattern of DAD. 'Treatment' with high-dose corticosteroids with or without an immunosuppressant proved ineffective and represents the coup de grace for these patients. Provision of excellent supportive care and the search for and treatment of the 'underlying cause' remain the only options. IPF exacerbations require rapid decisions about when and whether to initiate mechanical support. Admission to an intensive care unit (ICU) is a particular clinical and ethical challenge because of the extremely poor outcome. Transplantation in the ICU setting often presents insurmountable difficulties.
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Affiliation(s)
- Spyros A Papiris
- 2nd Pulmonary Department, Attikon University Hospital, Athens Medical School, National and Kapodistrian University of Athens, 1 Rimini Street, 12462, Haidari, Greece.
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Calkovska A, Mokra D, Calkovsky V. Lung surfactant alterations in pulmonary thromboembolism. Eur J Med Res 2010; 14 Suppl 4:38-41. [PMID: 20156722 PMCID: PMC3521350 DOI: 10.1186/2047-783x-14-s4-38] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Beside neonatal respiratory distress syndrome, secondary surfactant deficiency may occur in patients with mature lungs. Recent studies revealed quantitative and qualitative changes of lung surfactant in pulmonary thromboembolism (PTE) concerning the total phospholipids content in BAL fluid, alterations in surfactant phospholipids classes and a large-to-small aggregates ratio. Reduced expression of surfactant protein A (SP-A) mRNA and SP-A in lung tissue after pulmonary embolism was found. Serum levels of SP-A were significantly higher in patients with PTE than in other lung diseases, except COPD. Surfactant changes in PTE may result from damage of type II cells by hypoxia, leakage of plasma proteins into the airspaces and/or by reactive oxygen species. They can contribute to lung atelectasis and edema, and a further reduction in oxygen saturation as seen in clinical picture of PTE. Surfactant changes are reliable marker of lung injury that might become a prognostic indicator in patients with pulmonary thromboembolism.
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Affiliation(s)
- A Calkovska
- Department of Physiology, Jessenius Faculty of Medicine, Comenius University, Mala Hora 4, SK-03754 Martin, Slovakia.
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Maniatis NA, Letsiou E, Orfanos SE, Kardara M, Dimopoulou I, Nakos G, Lekka ME, Roussos C, Armaganidis A, Kotanidou A. Inhaled activated protein C protects mice from ventilator-induced lung injury. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R70. [PMID: 20403177 PMCID: PMC2887192 DOI: 10.1186/cc8976] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 02/14/2010] [Accepted: 04/19/2010] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Activated Protein C (APC), an endogenous anticoagulant, improves tissue microperfusion and endothelial cell survival in systemic inflammatory states such as sepsis, but intravenous administration may cause severe bleeding. We have thus addressed the role of APC delivered locally by inhalation in preventing acute lung injury from alveolar overdistention and the subsequent ventilator-induced lung injury (VILI). We also assessed the effects of APC on the activation status of Extracellular- Regulated Kinase 1/2 (ERK) pathway, which has been shown to be involved in regulating pulmonary responses to mechanical stretch. METHODS Inhaled APC (12.5 microg drotrecogin-alpha x 4 doses) or saline was given to tracheotomized C57/Bl6 mice starting 20 min prior to initiation of injurious mechanical ventilation with tidal volume 25 mL/Kg for 4 hours and then hourly thereafter; control groups receiving inhaled saline were ventilated with 8 mL/Kg for 30 min or 4 hr. We measured lung function (respiratory system elastance H), arterial blood gases, surrogates of vascular leak (broncho-alveolar lavage (BAL) total protein and angiotensin-converting enzyme (ACE)-activity), and parameters of inflammation (BAL neutrophils and lung tissue myeloperoxidase (MPO) activity). Morphological alterations induced by mechanical ventilation were examined in hematoxylin-eosin lung tissue sections. The activation status of ERK was probed in lung tissue homogenates by immunoblotting and in paraffin sections by immunohistochemistry. The effect of APC on ERK signaling downstream of the thrombin receptor was tested on A549 human lung epithelial cells by immunoblotting. Statistical analyses were performed using ANOVA with appropriate post-hoc testing. RESULTS In mice subjected to VILI without APC, we observed hypoxemia, increased respiratory system elastance and inflammation, assessed by BAL neutrophil counts and tissue MPO activity. BAL total protein levels and ACE activity were also elevated by VILI, indicating compromise of the alveolo-capillary barrier. In addition to preserving lung function, inhaled APC prevented endothelial barrier disruption and attenuated hypoxemia and the inflammatory response. Mechanistically, we found a strong activation of ERK in lung tissues by VILI, which was prevented by APC, suggestive of pathogenetic involvement of the Mitogen-Activated Kinase pathway. In cultured human lung epithelial cells challenged by thrombin, APC abrogated the activation of ERK and its downstream effector, cytosolic Phospholipase A2. CONCLUSIONS Topical application of APC by inhalation may effectively reduce lung injury induced by mechanical ventilation in mice.
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Affiliation(s)
- Nikolaos A Maniatis
- 2nd Dept, of Critical Care, Attikon Hospital, National and Kapodistrian University of Athens Medical School, Rimini 1, Haidari, Greece.
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Michelotto P, Muehlmann L, Zanatta A, Bieberbach E, Fernandes L, Nishiyama A. Platelet-Activating Factor and Evidence of Oxidative Stress in the Bronchoalveolar Fluid of Thoroughbred Colts during Race Training. J Vet Intern Med 2010; 24:414-9. [DOI: 10.1111/j.1939-1676.2010.0459.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Roca O, Gómez-Ollés S, Cruz MJ, Muñoz X, Griffiths MJD, Masclans JR. Mechanical ventilation induces changes in exhaled breath condensate of patients without lung injury. Respir Med 2010; 104:822-8. [PMID: 20138493 DOI: 10.1016/j.rmed.2010.01.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 12/09/2009] [Accepted: 01/17/2010] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Measurement of biomarkers in exhaled breath condensate (EBC) may be useful for monitoring lung inflammation and injury in mechanically ventilated patients. The aim of this study was to analyze changes in biomarkers of inflammation in EBC associated with prolonged mechanical ventilation. METHODS EBC samples were collected from critically ill patients weaning from mechanical ventilation without lung disease and from healthy nonsmokers. The following parameters were measured: pH after helium deaeration, nitrogen oxide and 8-isoprostane concentrations. RESULTS EBC was obtained from 10 patients and 20 controls. Ventilation time before the start of sample collection was 250 (85-714)h. The post-deaeration pH of EBC samples was significantly lower in ventilated patients than controls (7.50 [7.28-7.70] vs 8.07 [7.60-8.40]; P=0.008). Ventilation time before sample collection inversely correlated with pH (r=-0.636; P=0.048). A significantly higher concentration of nitrogen oxide (muM) was seen in ventilated patients vs controls (66.22 [22.26-83.13] vs 15.06 [10.73-23.30]; P=0.002), whereas levels of 8-isoprostane (pg/mL) were not significantly different between both groups (5.73 [4.0-11.4] vs 9.09 [6.63-11.43]; P=0.169). The nitrogen oxide concentration correlated negatively with dynamic compliance (r=-0.952; P<0.001) and positively with respiratory rate (r=0.683; P=0.029). CONCLUSIONS EBC analysis is a non-invasive technique that can be used to monitor ventilated patients. Mechanically ventilated patients had higher EBC acidity and nitrogen oxide concentrations. Duration of ventilation correlated with breath condensate pH.
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Affiliation(s)
- Oriol Roca
- Intensive Care Medicine Department (General Area), Hospital Universitari Vall d'Hebron, Pg. Vall d'Hebron 119-129, C.P. 08035 Barcelona, Spain.
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Pinheiro de Oliveira R, Hetzel MP, dos Anjos Silva M, Dallegrave D, Friedman G. Mechanical ventilation with high tidal volume induces inflammation in patients without lung disease. Crit Care 2010; 14:R39. [PMID: 20236550 PMCID: PMC2887148 DOI: 10.1186/cc8919] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 10/26/2009] [Accepted: 03/18/2010] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Mechanical ventilation (MV) with high tidal volumes may induce or aggravate lung injury in critical ill patients. We compared the effects of a protective versus a conventional ventilatory strategy, on systemic and lung production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) in patients without lung disease. METHODS Patients without lung disease and submitted to mechanical ventilation admitted to one trauma and one general adult intensive care unit of two different university hospitals were enrolled in a prospective randomized-control study. Patients were randomized to receive MV either with tidal volume (VT) of 10 to 12 ml/kg predicted body weight (high VT group) (n = 10) or with VT of 5 to 7 ml/kg predicted body weight (low VT group) (n = 10) with an oxygen inspiratory fraction (FIO2) enough to keep arterial oxygen saturation >90% with positive end-expiratory pressure (PEEP) of 5 cmH2O during 12 hours after admission to the study. TNF-alpha and IL-8 concentrations were measured in the serum and in the bronchoalveolar lavage fluid (BALF) at admission and after 12 hours of study observation time. RESULTS Twenty patients were enrolled and analyzed. At admission or after 12 hours there were no differences in serum TNF-alpha and IL-8 between the two groups. While initial analysis did not reveal significant differences, standardization against urea of logarithmic transformed data revealed that TNF-alpha and IL-8 levels in bronchoalveolar lavage (BAL) fluid were stable in the low VT group but increased in the high VT group (P = 0.04 and P = 0.03). After 12 hours, BALF TNF-alpha (P = 0.03) and BALF IL-8 concentrations (P = 0.03) were higher in the high VT group than in the low VT group. CONCLUSIONS The use of lower tidal volumes may limit pulmonary inflammation in mechanically ventilated patients even without lung injury. CLINICAL TRIAL REGISTRATION NCT00935896.
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Affiliation(s)
- Roselaine Pinheiro de Oliveira
- Central Intensive Care Unit, Complexo Hospitalar Santa Casa, Rua Prof. Annes Dias, 295, Porto Alegre, 90020-090, Brazil
- Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos n° 2.350, Porto Alegre, 90035-903, Brazil
| | - Marcio Pereira Hetzel
- Central Intensive Care Unit, Complexo Hospitalar Santa Casa, Rua Prof. Annes Dias, 295, Porto Alegre, 90020-090, Brazil
| | - Mauro dos Anjos Silva
- Central Intensive Care Unit, Complexo Hospitalar Santa Casa, Rua Prof. Annes Dias, 295, Porto Alegre, 90020-090, Brazil
| | - Daniele Dallegrave
- Central Intensive Care Unit, Complexo Hospitalar Santa Casa, Rua Prof. Annes Dias, 295, Porto Alegre, 90020-090, Brazil
| | - Gilberto Friedman
- Central Intensive Care Unit, Complexo Hospitalar Santa Casa, Rua Prof. Annes Dias, 295, Porto Alegre, 90020-090, Brazil
- Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos n° 2.350, Porto Alegre, 90035-903, Brazil
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History of mechanical ventilation may affect respiratory mechanics evolution in acute respiratory distress syndrome. J Crit Care 2009; 24:626.e1-6. [PMID: 19427758 DOI: 10.1016/j.jcrc.2009.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 02/03/2009] [Accepted: 02/16/2009] [Indexed: 12/17/2022]
Abstract
PURPOSE The aim of this study was to investigate the effect of mechanical ventilation (MV) before acute respiratory distress syndrome (ARDS) on subsequent evolution of respiratory mechanics and blood gases in protectively ventilated patients with ARDS. METHODS Nineteen patients with ARDS were stratified into 2 groups according to ARDS onset relative to the onset of MV: In group A (n = 11), MV was applied at the onset of ARDS; in group B (n = 8), MV had been initiated before ARDS. Respiratory mechanics and arterial blood gas were assessed in early (<or=3 days) and late (8-11 days) ARDS, on zero positive end-expiratory pressure and positive end-expiratory pressure of 10 cm H(2)O. RESULTS In group A, Pao(2)/fractional inspired oxygen concentration increased (121 +/- 43 vs 161 +/- 60 mm Hg) and minimal resistance of respiratory system decreased (8.3 +/- 1.8 vs 6.0 +/- 2.1 cm H(2)O L(-1) s(-1)) from early to late ARDS. In group B, static elastance of respiratory system increased in the late stage (30.4 +/- 7.8 vs 36.4 +/- 9.9 cm H(2)O/L). In both groups, positive end-expiratory pressure application resulted in Pao(2)/fractional inspired oxygen concentration improvement and minimal resistance of respiratory system decreases in both stages. CONCLUSION In protectively ventilated patients with ARDS, late alteration of respiratory mechanics occurs more commonly in patients who have been ventilated before ARDS onset, suggesting that the history of MV affects the subsequent progress of ARDS even when using protective ventilation.
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The effects of long-term conventional mechanical ventilation on the lungs of adult rats*. Crit Care Med 2008; 36:2381-7. [DOI: 10.1097/ccm.0b013e318180b65c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schuster KM, Alouidor R, Barquist ES. Nonventilatory interventions in the acute respiratory distress syndrome. J Intensive Care Med 2008; 23:19-32. [PMID: 18230633 DOI: 10.1177/0885066607310166] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Acute respiratory distress syndrome was first described in 1967. Acute respiratory distress syndrome and acute lung injury are diseases the busy intensivist treats almost daily. The etiologies of acute respiratory distress syndrome are many. A significant distinction is based on whether the insult to the lung was direct, such as in pneumonia, or indirect, such as trauma or sepsis. Strategies for managing patients with acute respiratory distress syndrome/acute lung injury can be subdivided into 2 large groups, those based in manipulation of mechanical ventilation and those based in nonventilatory modalities. This review focuses on the nonventlilatory strategies and includes fluid restriction, exogenous surfactant, inhaled nitric oxide, manipulation of production, or administration of eicosanoids, neuromuscular blocking agents, prone position ventilation, glucocorticoids, extracorporeal membrane oxygenation, and administration of beta-agonists. Most of these therapies either have not been studied in large trials or have failed to show a benefit in terms of long-term patient mortality. Many of these therapies have shown promise in terms of improved oxygenation and may therefore be beneficial as rescue therapy for severely hypoxic patients. Recommendations regarding the use of each of these strategies are made, and an algorithm for implementing these strategies is suggested.
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Affiliation(s)
- Kevin M Schuster
- Section of Trauma, Surgical Critical Care and Surgical Emergencies, Yale University School of Medicine, New Haven, Connecticut, USA
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Frank JA, Parsons PE, Matthay MA. Pathogenetic significance of biological markers of ventilator-associated lung injury in experimental and clinical studies. Chest 2007; 130:1906-14. [PMID: 17167015 PMCID: PMC2764530 DOI: 10.1378/chest.130.6.1906] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
For patients with acute lung injury, positive pressure mechanical ventilation is life saving. However, considerable experimental and clinical data have demonstrated that how clinicians set the tidal volume, positive end-expiratory pressure, and plateau airway pressure influences lung injury severity and patient outcomes including mortality. In order to better identify ventilator-associated lung injury (VALI), clinical investigators have sought to measure blood-borne and airspace biological markers of VALI. At the same time, several laboratory-based studies have focused on biological markers of inflammation and organ injury in experimental models in order to clarify the mechanisms of ventilator-induced lung injury (VILI) and VALI. This review summarizes data on biological markers of VALI and VILI from both clinical and experimental studies with an emphasis on markers identified in patients and in the experimental setting. This analysis suggests that measurement of some of these biological markers may be of value in diagnosing VALI and in understanding its pathogenesis.
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Affiliation(s)
- James A Frank
- Division of Pulmonary and Critical Care Medicine, University of California-San Francisco, 4150 Clement Street, Mail Stop 111D, San Francisco, CA 94121, USA.
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van Veenendaal MB, van Kaam AH, Haitsma JJ, Lutter R, Lachmann B. Open lung ventilation preserves the response to delayed surfactant treatment in surfactant-deficient newborn piglets. Crit Care Med 2006; 34:2827-34. [PMID: 17006360 DOI: 10.1097/01.ccm.0000243794.09377.96] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Delayed surfactant treatment (>2 hrs after birth) is less effective than early treatment in conventionally ventilated preterm infants with respiratory distress syndrome. The objective of this study was to evaluate if this time-dependent efficacy of surfactant treatment is also present during open lung ventilation. DESIGN Prospective, randomized controlled animal study. SETTING University-affiliated research laboratory. SUBJECTS Thirty-eight newborn piglets. INTERVENTIONS Following repeated whole-lung lavage, animals were randomly allocated to conventional positive pressure ventilation (PPVCON) using a positive end-expiratory pressure (PEEP) of 5 cm H2O and a tidal volume of 7 mL/kg or open lung positive pressure ventilation (PPVOLV). During PPVOLV, collapsed alveoli were actively recruited and thereafter stabilized with sufficient PEEP. Within each ventilation group, animals received surfactant (25 mg/kg) either after 2 hrs (PPVCON-2 and PPVOLV-2) or after 4 hrs (PPVCON-4 and PPVOLV-4) of ventilation. A control group received surfactant immediately after lung lavage. Following surfactant administration, all animals were conventionally ventilated for an additional 2 hrs. MEASUREMENTS AND MAIN RESULTS Two hours after surfactant treatment, both oxygenation and lung mechanics showed a clear deterioration in the PPVCON-4 group compared with PPVCON-2 and the control group. However, this deterioration of the surfactant response over time was not observed during PPVOLV. Analysis of the bronchoalveolar lavage fluid obtained at the end of the experiment showed that the protein concentration and the conversion of large to small aggregate surfactant was significantly higher in the PPVCON-4 group compared with the PPVCON-2 group while comparable in both PPVOLV groups. In addition, interleukin-8 and myeloperoxidase levels tended to be higher in the PPVCON-4 group compared with the PPVOLV-4 group. CONCLUSIONS In contrast to conventional ventilation, open lung ventilation preserves the response to delayed surfactant treatment in surfactant-deficient newborn piglets. This sustained response is accompanied by an attenuation of secondary lung injury.
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Affiliation(s)
- Mariëtte B van Veenendaal
- Department of Neonatology, Emma Children's Hospital AMC, University of Amsterdam, Amsterdam, The Netherlands
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Abstract
Regardless of the cause, a common pathophysiological feature of patients with acute respiratory distress syndrome is a dysfunction of the endogenous surfactant system. Although exogenous surfactant therapy has proven to be an effective treatment for neonatal respiratory distress syndrome, no similar current effective therapy exists for patients with acute respiratory distress syndrome. This is mainly due to the complexity of the lung injury that is involved with this disorder. Results from clinical trials, to date, have failed to show an improvement in patient survival after administration of exogenous surfactant; however, ongoing and future research efforts suggest that this therapy may eventually be feasible.
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Affiliation(s)
- Adam Maruscak
- St. Joseph's Health Centre, London, ON, N6A 4V2, Canada
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Kesecioglu J, Haitsma JJ. Surfactant therapy in adults with acute lung injury/acute respiratory distress syndrome. Curr Opin Crit Care 2006; 12:55-60. [PMID: 16394785 DOI: 10.1097/01.ccx.0000199000.19393.a7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Several phase II and phase III studies have been performed to investigate safety, efficacy and the improvement of survival due to exogenous surfactant instillation in patients with acute lung injury or acute respiratory distress syndrome. In this review we will discuss the most recent of these studies, paying particular attention to differences in the composition of the exogenous surfactant used, the diverse modes of delivery and dose of therapy and the influence of mechanical ventilation. RECENT FINDINGS Several phase II studies performed on patients with acute lung injury or acute respiratory distress syndrome and a phase III study performed on a pediatric population have shown beneficial effects of surfactant on oxygenation and survival. No effect of exogenous surfactant has been shown on survival in phase III studies in adult patients. SUMMARY The changes in the surfactant system of patients with acute lung injury and acute respiratory distress syndrome form the rationale for the instillation of exogenous surfactant. There is enough evidence to use surfactant instillation for pediatric patients with acute lung injury. Due to the results of the randomized controlled trials performed so far, however, exogenous surfactant is not recommended for routine use in patients with acute lung injury or acute respiratory distress syndrome. In the future, other surfactants with different compositions may show beneficial effects.
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Affiliation(s)
- Jozef Kesecioglu
- Department of Intensive Care Medicine, University Medical Center, Utrecht, The Netherlands.
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Tsangaris H, Lekka M, Nakos G. Should we start considering surfactant for atelectasis? Am J Respir Crit Care Med 2005; 172:141; author reply 141-2. [PMID: 15980112 DOI: 10.1164/ajrccm.172.1.952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Tsangaris H, Nakos G. Ventilator-associated lung injury in healthy lung: how important is it? Crit Care Med 2005; 33:472-3; author reply 473. [PMID: 15699882 DOI: 10.1097/01.ccm.0000153611.15296.20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Gajic O, Afessa B, Hubmayr RD. Ventilator-Associated Lung Injury in Healthy Lung: How Important Is It? Crit Care Med 2005. [DOI: 10.1097/01.ccm.0000153605.16898.b2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Haitsma JJ, Papadakos PJ, Lachmann B. Surfactant therapy for acute lung injury/acute respiratory distress syndrome. Curr Opin Crit Care 2004; 10:18-22. [PMID: 15166845 DOI: 10.1097/00075198-200402000-00004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Currently, three phase III surfactant replacement trials for acute lung injury (ALI)/acute respiratory distress syndromes (ARDS) patients are underway. Although the efficacy of surfactant replacement therapy will first have to be proved in these phase III trials, recent reports indicate some enticing possibilities for the future of surfactant therapy. RECENT FINDINGS Patients requiring mechanical ventilation show alterations in their endogenous surfactant composition. Depending on the type of lung injury or the elapsed time, modifications to surfactant preparations could enhance the efficacy of these preparations. Surfactants that closely resemble natural surfactant, especially those containing surfactant proteins (SP-B/C) and nonphospholipids (cholesterol), are able to restore normal surfactant physiology. Furthermore, lipids that are able to withstand degradation by lipases could further enhance surfactant therapy. SUMMARY If surfactant therapy fulfills the promises expected from the ongoing phase III trials, future surfactant preparations may even enhance therapy efficacy and restore the altered endogenous surfactant pool as soon as possible.
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Affiliation(s)
- Jack J Haitsma
- Department of Anesthesiology, Erasmus-MC Faculty, Rotterdam, The Netherlands
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