THE EFFECT OF DEXAMETHASONE ON TIME-AVERAGED MEAN VELOCITY IN THE MIDDLE CEREBRAL-ARTERY IN VERY-LOW-BIRTH-WEIGHT INFANTS

The effect of repeated doses of dexamethasone (0.25 mg/kg/dose every 1 2 h) on time averaged mean velocity in the middle cerebral artery was assessed in ten ventilated very low birth weight infants requiring tre atment with dexamethasone for bronchopulmonary dysplasia or airway obs truction. The infants were studied by colour/duplex Doppler technique prior to the administration of the first and the third dose of dexamet hasone, and 10, 30, and 120 min after these doses. Dexamethasone treat ment was associated with an improvement in infant lung condition, an i ncrease in mean arterial blood pressure and a decrease in heart rate. The time averaged mean velocity was statistically significantly reduce d at 120 min after the first dose. This was not associated with a decr ease in PCO2. The observed reduction of 18% from baseline in the time averaged mean velocity is unlikely to be of clinical importance.