INHALED NITRIC-OXIDE VERSUS NEBULIZED PROSTAGLANDIN E-1 AND NEBULIZEDPROSTACYCLIN

Pulmonary hypertension and reduced arterial oxygenation are the clinic ally most relevant symptoms of acute respiratory failure. Inhaled nitr ic oxide (NO) proved to be effective in reducing pulmonary hypertensio n and improving arterial oxygenation. We hypothesized that the inhalat ion of vasodilatory agents such as prostacyclin or prostaglandin E-1 w ould have similar effects than inhaled NO. We tested this hypothesis i n an established model of ovine smoke inhalation injury. Sheep (N=6) w ere prepared for chronic study. Three days later, the sheep were insuf flated with cotton wool smoke under halothane anesthesia. After 24 h, first NO, then PGI(2), and thereafter PGE(1) were added to the inspire d air. Smoke inhalation injury caused a serious deterioration of pulmo nary hemodynamics and arterial oxygenation. All three compounds select ively reduced pulmonary hypertension, but none of them improved oxygen ation. Inhaled NO caused a slight but significant increase in methemog lobin, which could not been obtained during PGI(2) or PGE(1) nebulizat ion.