Effects of nicardipine and labetalol on the acute hemodynamic response to electroconvulsive therapy.
OBJECTIVE
To examine the acute hemodynamic effects of intravenous (i.v.) nicardipine and its ability to attenuate the hyperdynamic response to electroconvulsive therapy (ECT), when used alone or in combination with labetalol.


METHODS
Prospective, randomized, double-blind, positive-control, clinical investigation.


METHODS
University hospital.


METHODS
36 patients undergoing ECT.


METHODS
In a series of three studies, the hemodynamic effects of nicardipine were assessed prior to, during, and after ECT. After administration of glycopyrrolate 0.1 mg i.v., placebo (saline) or nicardipine was administered by rapid infusion (1, 2.5, 5, 10, and 15 mg) or bolus injection (1.25, 2.5, and 5 mg), either alone or in combination with labetalol 10 mg i.v. Unconsciousness was induced with methohexital 1 mg/kg i.v.; succinylcholine 1.2 to 1.5 mg/kg i.v. was administered for muscle relaxation. A bilateral electrical stimulus was delivered and the durations of motor and electroencephalographic (EEG) seizures were noted.


RESULTS
Mean arterial pressure (MAP) and heart rate (HR) values were recorded at 1- to 5-minute intervals throughout the study period. When administered as a rapid infusion, nicardipine 5 mg i.v. produced a significant decrease in MAP; however, nicardipine dosages of 10 to 15 mg i.v. did not produce a significantly greater decrease in MAP than 5 mg. Bolus administration of nicardipine 1.25 to 5 mg produced a rapid onset of its hemodynamic effects without exacerbating the cardiovascular depressant effects of methohexital. However, the decrease in MAP was accompanied by an increase in HR after administration of the 5 mg i.v. bolus dose. The acute hyperdynamic response to ECT was most effectively controlled by nicardipine 2.5 to 5 mg i.v. bolus, in combination with labetalol 10 mg i.v. Seizure duration was not significantly altered by the use of nicardipine as part of the anesthetic regimen for ECT.


CONCLUSIONS
Nicardipine 2.5 mg i.v. bolus in combination with labetalol 10 mg i.v. was the most effective pretreatment regimen for preventing the acute hyperdynamic response to ECT. However, this combination produced a 20% decrease in MAP immediately prior to ECT and a lower MAP at the time of discharge.
Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas 75235-9068, USA.
M N
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Avramov
L A
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Stool
P F
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White
M M
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Husain
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004338:Drug Combinations; D004565:Electroconvulsive Therapy; D004569:Electroencephalography; D006024:Glycopyrrolate / Q000008:administration & dosage / Q000627:therapeutic use; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007741:Labetalol / Q000008:administration & dosage / Q000627:therapeutic use*; D008723:Methohexital / Q000008:administration & dosage; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D009467:Neuromuscular Depolarizing Agents / Q000008:administration & dosage; D009529:Nicardipine / Q000008:administration & dosage / Q000627:therapeutic use*; D010919:Placebos; D011446:Prospective Studies; D012640:Seizures / Q000503:physiopathology / Q000517:prevention & control; D013390:Succinylcholine / Q000008:administration & dosage
D018686:Anesthetics, Intravenous; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D004338:Drug Combinations; D018727:Muscarinic Antagonists; D009467:Neuromuscular Depolarizing Agents; D010919:Placebos; D009529:Nicardipine; D008723:Methohexital; D013390:Succinylcholine; D007741:Labetalol; D006024:Glycopyrrolate