Objective: To investigate whether inhaled nitric oxide (INO) can preve
nt platelet activating factor (PAF)induced pulmonary hypertension and
shock. Design: Randomized controlled animal trial. Setting: Laboratory
. Subjects: Yorkshire swine. Interventions: Animals received general a
nesthesia and invasive hemodynamic monitoring, then PAF only, 2.5 mu g
/kg intravenously over 45 minutes (PAF group, n = 9) or PAF in additio
n to INO, 20 ppm (PAF-INO group, n = 6). Main Outcomes: Vascular press
ures (mean arterial and mean pulmonary), vascular resistance indexes (
systemic and pulmonary), cardiac indexes, and oxygen delivery and oxyg
en 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 pulmonar
y 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). Conclusion: The use of INO prevents pulmonary
hypertension, circulatory failure, and death during PAF-induced shock
.