ACUTE EFFECTS ON SYSTEMIC CIRCULATION AFTER INTRATRACHEAL INSTILLATION OF CUROSURF OR SURVANTA IN SURFACTANT-DEPLETED NEWBORN PIGLETS

Systemic vasodilatation in surfactant-depleted newborn piglets is indu ced by 200 mg/kg of modified porcine lung surfactant (Curosurf(TM)). T he aim of this investigation was to study whether this effect is depen dent on dose and could further be induced by instillation of a bovine surfactant preparation (Survanta (TM)). Twenty-two 3-5-d old piglets w ere subjected to repeated saline lung lavage and then randomized to on e of three groups. Instillation of either Curosurf 100 mg/kg (n = 8), Survanta 100 mg/kg (n = 7) or Curosurf 200 mg/kg (n = 7) was performed through the endotracheal tube. Systemic vascular resistance decreased 7 (+/- 4)%, 15 (+/- 12)% and 18 (+/- 6)% in the three groups, respect ively (p < 0.05 in all three groups). A significant difference between the high and low dose Curosurf groups was found (p < 0.05), whereas n o significant difference was seen between the Curosurf 100 mg group an d the Survanta group. The decrease in vascular resistance was compensa ted by an increase in cardiac output, resulting in a stable mean arter ial blood pressure. In conclusion, both Curosurf and Survanta induce a significant decrease in systemic vascular resistance in surfactant-de pleted newborn piglets. A more pronounced effect was observed after 20 0 mg/kg than after 100 mg/kg of Curosurf.