Intravenous aminophylline and cerebral blood flow in preterm infants

The effect of aminophylline on cerebral blood flow (CBF) was studied in 10 preterm infants who were receiving 6.2 mg/kg intravenously over 20 minutes followed by a maintenance infusion. CBF was measured intermittently using near infrared spectroscopy. Heart rate, blood pressure, oxygen saturation, and transcutaneously measured carbon dioxide tension (TcPCO2) were recorded continuously. Aminophylline administration was associated with a fall in CBF from a median of 15.9 ml/100 g/min to 11.2 ml/100 g/min. Median fall in CBF was 4.1 ml/100 g/min (95% confidence interval 1.7 to 6.5). Heart rate rose and TcPCO2 fell in all infants, median fall being 0.66 kPa. The reduction in CBF was greater than would be expected on the basis of the modest fall in TcPCO2.