Acute effects of acetazolamide on cerebral blood flow velocity and pCO2 in the newborn infant.

Twelve infants with hydrocephalus were treated with acetazolamide. In those treated intravenously middle cerebral artery blood flow velocity increased by a median of 86% (range 54-150%). Maximum increase was reached within 2-20 min. The effect lasted as long as 3.5 hours. Intracranial pressure rose by a median of 4 mmHg (range 0-10 mmHg). There was no significant alteration in blood pressure or heart rate. Respiratory rate increased by approximately 10 breaths/min and the tcpCO2 rose by a median 0.2 kPa in infants with normal lungs. In infants treated orally, blood velocity rose by 35-40% at 60-80 min with no increase in intracranial pressure. In four infants with lung disease pCO2 rose by a median of 2.0 kPa (range 0.6 to 3.4 kPa). Acetazolamide was well tolerated in infants with normal lungs but should be used with caution in the presence of lung disease.