Inhaled nitric oxide prevents experimental platelet activating factor-induced shock.

Objective: To investigate whether inhaled nitric oxide (INO) can prevent platelet activating factor (PAF)-induced pulmonary hypertension and shock.

Design: Randomized controlled animal trial.

Setting: Laboratory.

Subjects: Yorkshire swine.

Interventions: Animals received general anesthesia and invasive hemodynamic monitoring, then PAF only, 2.5 micrograms/kg intravenously over 45 minutes (PAF group, n = 9) or PAF in addition to INO, 20 ppm (PAF-INO group, n = 6).

Main Outcome: Vascular pressures (mean arterial and mean pulmonary), vascular resistance indexes (systemic and pulmonary), cardiac indexes, and oxygen delivery and oxygen consumption.

Results: Mean arterial pressures, cardiac indexes, and oxygen delivery and consumption were significantly higher in the PAF-INO group. Mean pulmonary arterial pressures and systemic and pulmonary vascular resistance indexes were significantly lower in the PAF-INO group. There were 4 deaths (44%) in the PAF group vs none (0%) in the PAF-INO group (P = 10).

Conclusions: The use of INO prevents pulmonary hypertension, circulatory failure, and death during PAF-induced shock.