SURFACTANT BOLUS INSTILLATION - EFFECTS OF DIFFERENT DOSES ON BLOOD-PRESSURE AND CEREBRAL BLOOD-FLOW VELOCITIES

Fifteen preterm infants suffering from respiratory distress syndrome w ere randomly allocated to receive either high-dose (200 mg/kg) or low- dose (100 mg/kg) surfactant treatment. Retreatments were done with the low dose. Blood pressure, blood gases and cerebral blood flow velocit ies were determined before and after 24 bolus instillations. With the high dose mean blood pressure and mean cerebral blood flow velocity dr opped significantly. With the low dose only mean cerebral blood flow v elocity decreased; the course was unrelated to blood pressure or PCO2 fluctuations. The mechanisms leading to the observed circulatory chang es after surfactant instillation remain unclear.