Rectal nifedipine for the management of intraoperative hypertension

The effect of rectal administration of nifedipine for the management of intraoperative hypertension was studied in 12 adult neurosurgical patients, physical status II and III. A rise in mean arterial pressure (MAP) of > 20 mm Hg over the preoperative value was taken as the point at which rectal nifedipine (150 micrograms kg-1) was administered. Onset of action of nifedipine was observed in 4.5 +/- 1.5 min (mean +/- SD) with a peak effect at 30.8 +/- 10.7 min. MAP decreased from 124 +/- 4.5 mm Hg to 97 +/- 2.4 mm Hg. Heart rate and central venous pressure were unchanged. Endoscopic examination of the rectal mucosa 48 h after administration of nifedipine did not show any abnormality. Rectal nifedipine was found to be effective and safe for the management of intraoperative increases in arterial blood pressure as well as being convenient to administer to patients undergoing neurosurgical procedures.