Diltiazem reduces the dose requirement for nitroprusside-induced hypotension.

Author(s): Bernard JM, Moren J, Demeure D, Hommeril JL, Passuti N, Pinaud M

Affiliation(s): Departement d'Anesthesie-Reanimation Chirurgicale, Hotel-Dieu, Nantes, France.

Publication date & source: 1993-08, Anesth Analg., 77(2):318-23.

Publication type: Clinical Trial; Randomized Controlled Trial

The efficacy of diltiazem, a calcium channel blocker, for reducing the dose requirement for nitroprusside-induced hypotension was studied in 20 healthy patients during spine fusion for scoliosis. Anesthesia included methohexital (3 mg/kg followed by 3 mg.kg-1.h-1 intravenously), nitrous oxide, and alfentanil (40 micrograms/kg, followed by 0.7 microgram.kg-1.min-1 intravenously). Patients were assigned randomly to two groups, receiving either nitroprusside alone or nitroprusside and diltiazem (bolus of 80 micrograms/kg with two consecutive infusions of 4.5 micrograms.kg-1.min-1 during the first 30 min and then 1.3 micrograms.kg-1.min-1). Nitroprusside was used to maintain mean arterial pressure at 55-60 mm Hg in both groups. Hypotension was obtained in similar times, 4 min in the group receiving nitroprusside alone (range, 1-8 min) and 2 min in the group receiving nitroprusside and diltiazem (range, 1-8 min). Nitroprusside administration lasted 186 +/- 17 min (mean +/- SEM) in the group receiving nitroprusside alone and 214 +/- 26 min (mean +/- SEM) in the other group (NS). After hypotension, arterial blood pressure returned to its initial value in a time of 7 min in the group receiving nitroprusside alone (range, 5-9 min) and 9 min in the group receiving nitroprusside and diltiazem (range, 7-13 min) (NS). Cumulative doses of nitroprusside were larger in the group receiving nitroprusside alone (0.47 +/- 0.07 mg/kg; mean +/- SEM) than in the other group (0.24 +/- 0.05 mg/kg; mean +/- SEM) (P < 0.01). Significant increase in plasma thiocyanate concentration, cardiac index, and heart rate was observed only in the group receiving nitroprusside alone, but no intergroup differences were found.(ABSTRACT TRUNCATED AT 250 WORDS)