AMINOPHYLLINE AND DOPPLER TIME-AVERAGED MEAN VELOCITY IN THE MIDDLE CEREBRAL-ARTERY IN PRETERM NEONATES

Objective: The purpose of this study was to assess the effect of an in travenous loading dose of aminophylline (6 mg/kg) on Doppler time-aver aged mean velocity in the middle cerebral artery in ventilated preterm neonates. Methodology: Twenty infants were studied by colour/duplex D oppler technique prior to and at 5, 10, 30 and 60 min after the admini stration of aminophylline. Results: Aminophylline treatment was associ ated with a statistically significant reduction in time-averaged mean velocity from baseline (P<0.001) and an increase in heart rate (P<0.00 1) at all timepoints. The largest reduction in time-averaged mean velo city of 19% (95% confidence interval -10 to -28%) occurred at 10 min p ost-dose. There were no statistically significant changes in transcuta neous Pco(2) or mean arterial blood pressure. Conclusions: The observe d reduction of 19% from baseline in time-averaged mean velocity follow ing treatment with aminophylline alone is unlikely to be of clinical i mportance. Whether aminophylline in combination with other drugs that decrease central blood flow velocity such as indomethacin and/or dexam ethasone could result in a clinically significant reduction deserves f urther study.