INSTILLATION RATE EFFECTS OF EXOSURF ON CEREBRAL AND CARDIOVASCULAR HEMODYNAMICS IN PRETERM NEONATES

The acute effects of surfactant instillation rate on the cerebral and cardiovascular haemodynamics were studied in a randomised trial of 27 preterm neonates with respiratory distress syndrome Cerebral blood how velocity mean arterial blood pressure (MABP), blood gases and electro encephalogram (EEG) were continuously recorded before, during, and for at least 10 minutes after the administration of surfactant. The measu rements were repeated one, three, and six hours later. Left ventricula r output (LVO) and ductal patency were assessed 10 minutes before and then one, three, and six hours after surfactant administration. Surfac tant (Exosurf) was instilled rapidly over five minutes in 13 infants a nd slowly over 15 minutes in 14 infants. The rapid group showed a sign ificant but transient increase (mean 38%) in CBFV, a rise strongly rel ated to an increase in carbon dioxide tension. No significant change i n CBFV was observed in the slow group. There were no significant chang es in EEG, MABP, LVO, or ductal shunting in either group. The findings suggest that rapid instillation of Exosurf leads to an increase in CB FV and partial carbon dioxide pressure (Pco(2)) and requires a close m onitoring of blood gases to maintain adequate ventilation. Furthermore , the findings should alert clinicians to the need for slow infusion o f Exosurf.