Objective : The purpose of this study was to assess the effect of an intravenous loading dose of aminophylline (6 mg/kg) on Doppler time-averaged mean velocity in the middle cerebral artery in ventilated preterm neonates. Methodology : Twenty infants were studied by colour/duplex Doppler technique prior to and at 5, 10, 30 and 60 min after the administration of aminophylline. Results: Aminophylline treatment was associated with a statistically significant reduction in time-averaged mean velocity from baseline (P>0.001) and an increase in heart rate (P>0.001) at all timepoints. The largest reduction in time-averaged mean velocity of 19% (95% confidence interval - 10 to - 28%) occurred at 10 min post-dose. There were no statistically significant changes in transcutaneous Pco2 or mean arterial blood pressure. Conclusions: The observed reduction of 19% from baseline in time-averaged mean velocity following treatment with aminophylline alone is unlikely to be of clinical importance. Whether aminophylline in combination with other drugs that decrease central blood flow velocity such as indomethacin and/or dexamethasone could result in a clinically significant reduction deserves further study.
