Ductal shunting and effective systemic blood flow following single dose surfactant treatment in the premature baboon with hyaline membrane disease

We studied the hemodynamic effects of using natural surfactant in premature baboons with hyaline membrane disease (HMD). Study animals (n=5) received a single dose of surfactant immediately after delivery and control animals (n=8) did not. Using microspheres at 3, 8, and 23h we found no significant differences in left ventricular output, effective systemic flow, systemic-to-pulmonary patent ductus arteriosus (PDA) shunting, or in cerebral or renal organ blood flow. However, both groups had large PDA shunts (fraction of LVO to lungs >0.40-0.55 at 3 and 8h) resulting in low systemic perfusion (<80ml/min/kg). Single dose surfactant did not improve the myocardial dysfunction and low cerebral and renal blood flow which occur during treatment for HMD.