Document Detail


Recruitment maneuver in pulmonary and extrapulmonary experimental acute lung injury.
MedLine Citation:
PMID:  18496360     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: The aim of this study is to test the hypothesis that recruitment maneuvers (RMs) might act differently in models of pulmonary (p) and extrapulmonary (exp) acute lung injury (ALI) with similar transpulmonary pressure changes. DESIGN: Prospective, randomized, controlled experimental study. SETTING: University research laboratory. SUBJECTS: Wistar rats were randomly divided into four groups. In control groups, sterile saline solution was intratracheally (0.1 mL, Cp) or intraperitoneally (1 mL, Cexp) injected, whereas ALI animals received Escherichia coli lipopolysaccharide intratracheally (100 microg, ALIp) or intraperitoneally (1 mg, ALIexp). After 24 hrs, animals were mechanically ventilated (tidal volume, 6 mL/kg; positive end-expiratory pressure, 5 cm H2O) and three RMs (pressure inflations to 40 cm H2O for 40 secs, 1 min apart) applied. MEASUREMENTS AND MAIN RESULTS: PaO2, lung resistive and viscoelastic pressures, static elastance, lung histology (light and electron microscopy), and type III procollagen messenger RNA expression in pulmonary tissue were measured before RMs and at the end of 1 hr of mechanical ventilation. Mechanical variables, gas exchange, and the fraction of area of alveolar collapse were similar in both ALI groups. After RMs, lung resistive and viscoelastic pressures and static elastance decreased more in ALIexp (255%, 180%, and 118%, respectively) than in ALIp (103%, 59%, and 89%, respectively). The amount of atelectasis decreased more in ALIexp than in ALIp (from 58% to 19% and from 59% to 33%, respectively). RMs augmented type III procollagen messenger RNA expression only in the ALIp group (19%), associated with worsening in alveolar epithelium injury but no capillary endothelium lesion, whereas the ALIexp group showed a minor detachment of the alveolar capillary membrane. CONCLUSIONS: Given the same transpulmonary pressures, RMs are more effective at opening collapsed alveoli in ALIexp than in ALIp, thus improving lung mechanics and oxygenation with limited damage to alveolar epithelium.
Authors:
Douglas R Riva; Mariana B G Oliveira; Andréia F Rzezinski; Graziela Rangel; Vera L Capelozzi; Walter A Zin; Marcelo M Morales; Paolo Pelosi; Patricia R M Rocco
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Critical care medicine     Volume:  36     ISSN:  1530-0293     ISO Abbreviation:  Crit. Care Med.     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-06-03     Completed Date:  2008-06-17     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0355501     Medline TA:  Crit Care Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1900-8     Citation Subset:  AIM; IM    
Affiliation:
Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
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MeSH Terms
Descriptor/Qualifier:
Airway Resistance / physiology
Animals
Capillary Permeability / physiology
Collagen Type III / genetics
Disease Models, Animal
Endothelium, Vascular / pathology,  physiopathology
Gene Expression / physiology
Lung Compliance / physiology*
Microscopy, Electron
Oxygen / blood*
Pulmonary Alveoli / blood supply,  pathology,  physiopathology*
Pulmonary Atelectasis / pathology,  physiopathology
Pulmonary Gas Exchange / physiology
RNA, Messenger / genetics
Rats
Rats, Wistar
Respiratory Distress Syndrome, Adult / pathology,  physiopathology*
Respiratory Mechanics / physiology*
Reverse Transcriptase Polymerase Chain Reaction
Systemic Inflammatory Response Syndrome / pathology,  physiopathology*
Chemical
Reg. No./Substance:
0/Collagen Type III; 0/RNA, Messenger; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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