EFFICACY OF RIGHT ATRIAL INFUSION OF PGE1 IN SEPSIS-INDUCED PULMONARY-HYPERTENSION

In this study we investigated the effects of right atrial infusion of PGE1 (RAIPGE1) in doses from 40 to 500 ng/kg/min on sepsis-induced pulmonary artery hypertension (SIPAH). Thirteen pigs were randomized into a time-course group (n = 6) and a PGE1-treated group (n = 7). Pulmonary hypertension (PAH) was induced with the infusion of Pseudomonas Aeruginosa (PsAr) at a concentration of 2 × 108 CFU/20 kg/min in both groups. The infusion of PsAr caused a significant and persistent rise in mean pulmonary artery pressure (MPA), pulmonary vascular resistance (PVRI), right ventricular compliance (RVC), RV dp/dt, and right ventricular stroke work index (RVSWI), 30 min after the onset of infusion (P < 0.05 vs baseline). Systemic hemodynamics and gas exchange were not affected throughout the 3-hr period of infusion (P = NS); however, left ventricular compliance (LVC) was depressed at a MPA greater than 35 mm Hg. The RAIPGE1 following SIPAH caused a concentration-dependent reduction above 40 ng/kg/min of MPA, PVRI, RVSWI, and RV dp/dt (P < 0.05, 120 and 500 ng/kg/min vs PAH). RVC returned to baseline values during the infusion of PGE1. Systemic hemodynamics, including oxygen delivery and extraction, were unaffected by the infusion of PGE1, but LVC was improved (P < 0.05, PGE1 500 vs PAH). The infusion of PGE1 caused a concentration-dependent rise in shunt fraction (Qs/Qt) and alveolar-arterial oxygen gradients which reached statistical significance during the infusion of 500 ng/kg/min. Our data show that RAIPGE1 is effective in ameliorating RV and pulmonary hemodynamics, but at the largest dose it negatively affects gas exchange. © 1990.