Large tidal volume mechanical ventilation induces vascular dysfunction in rats.

Background: Experimental studies have shown that mechanical ventilation using high tidal volumes (V(T)) damages the lungs, causing pulmonary edema. We tested the hypothesis that high V(T) ventilation in rats induces major vascular dysfunction.

Methods: Healthy Sprague-Dawley rats, weighing (mean +/- SD) 340 +/- 15 g, were ventilated with either V(T) = 9 mL/kg and positive end-expiratory pressure (PEEP) = 8 (n = 8) or V(T) = 35 mL/kg and PEEP = 0 (n = 8).