Effects of nifedipine on intracranial pressure in neurosurgical patients with arterial hypertension.

The effects of nifedipine, 20 mg administered via a nasogastric tube, on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were examined. Nifedipine was administered to treat arterial hypertension (greater than 180 mm Hg, systolic). Ten measurements were made in eight patients with cerebrovascular disease or head trauma. The mean arterial blood pressure (MABP) and ICP were measured before and for 30 minutes after the administration of nifedipine. The MABP gradually decreased and reached its lowest value at approximately 10 minutes after initiation of nifedipine administration, and thereafter remained unchanged. The MABP decreased significantly from 128 +/- 8 (mean +/- standard deviation) to 109 +/- 7 mm Hg, and the CPP decreased from 105 +/- 11 to 84 +/- 10 mm Hg. The ICP increased by 1 to 10 mm Hg in eight of 10 measurements, and the mean change of ICP from 19 +/- 7 to 22 +/- 6 mm Hg was statistically significant. These changes were not accompanied by alterations in neurological signs. The results suggest that enteral nifedipine produces a small but statistically significant increase in ICP. Accordingly, neurological signs must be closely observed to detect deterioration, which can be caused by an increase in ICP and/or a decrease in CPP.