NICARDIPINE FOR CONTROLLED HYPOTENSION DURING SPINAL SURGERY

Nicardipine is the first intravenously administered dihydropyridine ca lcium channel blocker. Its primary physiologic actions include vasodil atation with limited effects on the inotropic and dromotropic function of the myocardium. Several reports have documented its use in adult p atients for pharmacologic control of blood pressure. We present our ex perience with nicardipine as an agent for controlled hypotension durin g spinal surgery in 24 children. After the induction of general anesth esia, nicardipine was started at 5 (22 patients) or 10 mu g/kg/min (tw o patients). The target mean arterial pressure (MAP) of 55-65 mm Hg wa s reached in 5.1 +/- 2.1 min (range, 2-10). Intraoperative infusion re quirements to maintain the target MAP varied from 0.5 to 7 mu g/kg/min (mean, 2.5 +/- 1.1). No adverse effects related to nicardipine were n oted. Nicardipine appears to be an effective agent for controlled hypo tension in children. Future studies are required to determine its adva ntages/disadvantages compared with more commonly used agents such as s odium nitroprusside or adrenergic antagonists.