Prostaglandin E1 Selectively Reduces Group B β-Hemolytic Streptococci–Induced Pulmonary Hypertension in Newborn Piglets

• Group B β-hemolytic streptococci (GBS)–induced pulmonary hypertension was generated in ten newborn piglets. Intravenous infusions of either prostaglandin E₁ (PGE₁) (n = 5) or placebo (n = 5) were begun after 60 minutes of stable pulmonary hypertension. The effects of these interventions on cardiopulmonary hemodynamics were studied. Pulmonary artery pressure (PAP) increased similarly in both groups during the first 60 minutes of GBS infusion. By two hours after intervention, PAP was significantly lower in the animals given PGE₁ (20±4 vs 32±5 mm Hg for PGE₁ vs placebo). The ratio of pulmonary to systemic vascular resistance followed a pattern analogous to PAP, increasing with the GBS infusion, indicating selective pulmonary vasoconstriction. The pulmonary vascular resistance/systemic vascular resistance ratio decreased after intervention in the group given PGE₁ only (0.25 ±0.08 vs 0.50 ±0.12 for PGE₁ vs placebo), indicating selective pulmonary vasodilation. Transient systemic hypotension was noted at one hour after initiation of PGE¹ infusion. Prostaglandin E¹ infusion selectively improved GBS-induced pulmonary hypertension and hypoxemia in newborn piglets with only transient systemic hypotension.

(AJDC 1989;143:343-347)