The effects of pentoxifylline on pulmonary function following smoke inhalation

Bronchopulmonary injury secondary to smoke inhalation is a significant comorbid factor following major thermal trauma. The present study evaluates the effects of pentoxifylline (PTX) on pulmonary function in an ovine model of inhalation injury. Following smoke exposure to produce a moderate inhalation injury, 16 animals were divided into two groups. Group 1 animals (n = 8) were untreated; Group 2 animals (n = 8) were treated continuously with pentoxifylline following smoke exposure. The animals were observed in the unintubated, awake state for 48 hr. Cardiopulmonary variables and blood gases were measured serially. Ventilation perfusion distribution (VA/Q), analyzed using the multiple inert gas elimination technique, and bronchoalveolar lavage (BAL) were performed at 48 hr. The wet to dry lung weight ratio was measured following necropsy. In Group 2, the progressive hypoxemia observed following smoke inhalation was attenuated with less VA/Q mismatching than in Group 1 (P < 0.05). Pulmonary hypertension secondary to increased vascular resistance was also attenuated in Group 2 (P < 0.05). In BAL fluid, polymorphonuclear leukocytes, total protein content, and conjugated dienes were less in Group 2 than in Group 1 (P < 0.05). Plasma-conjugated diene levels were also lower in Group 2 at 48 hr. Extravascular lung water and decrease in lung compliance were greater in Group 1. There was less morphologic evidence of airway injury in Group 2 compared to Group 1. The improvement of pulmonary function following treatment with PTX suggests that this agent may be useful in the management of smoke inhalation injury.