Maintaining end-expiratory transpulmonary pressure prevents worsening of ventilator-induced lung injury caused by chest wall constriction in surfactant-depleted rats
Articolo
Data di Pubblicazione:
2010
Citazione:
Maintaining end-expiratory transpulmonary pressure prevents worsening of ventilator-induced lung injury caused by chest wall constriction in surfactant-depleted rats / S.H. Loring, M. Pecchiari, P. Della Valle, A. Monaco, G. Gentile, E. D'Angelo. - In: CRITICAL CARE MEDICINE. - ISSN 1530-0293. - 38:12(2010 Dec), pp. 2358-2364.
Abstract:
Objective: To see whether in acute lung injury 1) compression of the lungs caused by thoracoabdominal constriction degrades lung function and worsens ventilator-induced lung injury; and 2) maintaining end-expiratory transpulmonary pressure by increasing positive end-expiratory pressure reduces the deleterious effects of chest wall constriction.
Design: Experimental study in rats.
Setting: Physiology laboratory.
Interventions: Acute lung injury was induced in three groups of nine rats by saline lavage. Nine animals immediately killed served as a control group. Group L had lavage only, group LC had the chest wall constricted with an elastic binder, and group LCP had the same chest constriction but with positive end-expiratory pressure raised to maintain end-expiratory transpulmonary pressure. After lavage, all groups were ventilated with the same pattern for 1(1)/(2) hrs.
Measurements and Main Results: Transpulmonary pressure, measured with an esophageal balloon catheter, lung volume changes, arterial blood gasses, and pH were assessed during mechanical ventilation. Lung wet-to-dry ratio, albumin, tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, interleukin-10, and macrophage inflammatory protein-2 in serum and bronchoalveolar lavage fluid and serum E-selectin and von Willebrand Factor were measured at the end of mechanical ventilation. Lavage caused hypoxemia and acidemia, increased lung resistance and elastance, and decreased end-expiratory lung volume. With prolonged mechanical ventilation, lung mechanics, hypoxemia, and wet-to-dry ratio were significantly worse in group LC. Proinflammatory cytokines except E-selectin were elevated in serum and bronchoalveolar lavage fluid in all groups with significantly greater levels of tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 in group LC, which also exhibited significantly worse bronchiolar injury and greater heterogeneity of airspace expansion at a fixed transpulmonary pressure than other groups.
Conclusions: Chest wall constriction in acute lung injury reduces lung volume, worsens hypoxemia, and increases pulmonary edema, mechanical abnormalities, proinflammatory mediator release, and histologic signs of ventilator-induced lung injury. Maintaining end-expiratory transpulmonary pressure at preconstriction levels by adding positive end-expiratory pressure prevents these deleterious effects.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
esophageal pressure; respiratory mechanics; rat; acute lung injury; chest wall
Elenco autori:
S.H. Loring, M. Pecchiari, P. Della Valle, A. Monaco, G. Gentile, E. D'Angelo
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