Effects of mean airway pressure and tidal excursion on lung injury induced by mechanical ventilation in an isolated perfused rabbit lung model.

Details

Serval ID
serval:BIB_12528
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Effects of mean airway pressure and tidal excursion on lung injury induced by mechanical ventilation in an isolated perfused rabbit lung model.
Journal
Critical Care Medicine
Author(s)
Broccard A.F., Hotchkiss J.R., Suzuki S., Olson D., Marini J.J.
ISSN
0090-3493
Publication state
Published
Issued date
1999
Volume
27
Number
8
Pages
1533-1541
Language
english
Notes
Publication types: Comparative Study ; In Vitro ; Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S. Publication Status: ppublish
Abstract
OBJECTIVE: To study the relative contributions of mean airway pressure (mPaw) and tidal excursion (V(T)) to ventilator-induced lung injury under constant perfusion conditions. DESIGN: Prospective, randomized study. SETTING: Experimental animal laboratory. SUBJECTS: Fifteen sets of isolated rabbit lungs. INTERVENTIONS: Rabbit lungs were perfused (constant flow, 500 mL/min; capillary pressure, 10 mm Hg) and randomized to be ventilated at identical peak transpulmonary pressure (pressure control ventilation [30 cm H2O and frequency of 20/min]) with three different ventilatory patterns that differed from each other by either mPaw or V(T): group A (low mPaw [13.4+/-0.2 cm H2O]/large V(T) [55+/-8 mL], n = 5); group B (high mPaw [21.2+/-0.2 cm H2O]/small V(T) [18+/-1 mL], n = 5); and group C (high mPaw [21.8+/-0.5 cm H2O]/large V(T) [53+/-5 mL], n = 5). MEASUREMENTS AND MAIN RESULTS: Continuous weight gain (edema formation), change in ultrafiltration coefficient (deltaKf, vascular permeability index), and histology (lung hemorrhage) were examined. In group A, deltaKf (0.08+/-0.08 g/min/cm H2O/100 g) was less than in group B (0.28+/-0.19 g/min/cm H2O/100 g) or group C (0.41+/-0.29 g/min/cm H2O/100 g) (p = .05). Group A experienced significantly less hemorrhage (histologic score, 5.4+/-2.2) than groups B (10.3+/-2.1) and C (11.1+/-3.0) (p < .05). A similar trend was observed for weight gain. In contrast to tidal excursion, mPaw was found to be a significant factor for lung hemorrhage and increased Kf (two-way analysis of variance; p < .05). Weight gain (r2 = .54, p = .04) and lung hemorrhage (r2 = .65, p = .01) correlated with the mean pulmonary artery pressure changes that resulted from the implementation of the ventilatory strategies. The difference between the changes in mPaw and mean pulmonary artery pressure linearly predicted deltaKf (p = .005 and .05, respectively, r2 = 0.73). CONCLUSIONS: Under these experimental conditions, mPaw contributes more than tidal excursion to lung hemorrhage and permeability alterations induced by mechanical ventilation.
Keywords
Airway Resistance, Analysis of Variance, Animals, Disease Models, Animal, Hemodynamics, Linear Models, Organ Size, Positive-Pressure Respiration/adverse effects, Positive-Pressure Respiration/methods, Predictive Value of Tests, Prospective Studies, Rabbits, Random Allocation, Reproducibility of Results, Respiratory Distress Syndrome, Adult/etiology, Respiratory Distress Syndrome, Adult/pathology, Tidal Volume
Pubmed
Web of science
Create date
19/11/2007 12:03
Last modification date
20/08/2019 12:40
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