AMINOPHYLLINE THERAPY AND CEREBRAL BLOOD-FLOW VELOCITY IN PRETERM INFANTS

Pulsed Doppler ultrasound was used to evaluate the cerebral blood flow velocity (CBFV), in the middle and anterior cerebral arteries in 10 i nfants before and after the administration of aminophylline (7.5 mg/kg ). Mean CBFV, heart rate, blood pressure, oxygen and carbon dioxide te nsions were recorded before the loading dose, and then at 1, 2, 6 and 24h after completion of the infusion. Mean CBFV in the middle and ante rior cerebral arteries were 16.8 cm/s and 10.8 cm/s respectively prior to the infusion. There was a significant decrease (P<0.05) in velocit ies in both arteries at 1 and 2 h post drug therapy, which returned to base values by 6 h, and remained as such at 24 h. The heart rate incr eased (P<0.05) after the infusion, while no consistent changes were ob served in blood pressure or oxygen tension. Carbon dioxide levels were significantly reduced (P<0.05) at 2 h. The reduction in CBFV, however , was more than would be expected on the basis of the change in carbon dioxide levels alone, suggesting that other factors may be exerting a n influence. While no adverse effects were noted in the infants studie d, it is suggested that aminophylline should be used judiciously in si ck preterm infants at highest risk from ischaemic brain injury.