Objective: To observe the effects of the prone position and the need for positive end-expiratory pressure (PEEP) to improve oxygenation.
Methods:Sixteen rats were anesthetized and ventilated at a tidal volume of 8 mL/kg, respiratory rate of 60 rpm and PEEP = 0 cmH 2 O (ZEEP), in the supine position for 30 minutes. Lung injury was then induced by means of intratracheal instillation of hydrochloric acid. Once the injury was established, rats were placed in the prone position for a further 30 minutes and randomized into two groups: in group 1 PEEP = 5 cmH 2 O was added; while group 2 was kept on ZEEP. Measurements of pulmonary mechanics, arterial blood gas analysis and mean arterial pressure were taken at the end of each phase.