Electroconvulsive therapy-induced cardiac arrhythmias during anesthesia with methohexital, thiamylal, or thiopental sodium.

Abstract

STUDY OBJECTIVE:

To determine the frequency of electroconvulsive therapy (ECT)-induced arrhythmias under methohexital, thiamylal, or thiopental sodium anesthesia with and without atropine premedication.

DESIGN:

A randomized, double-blind study, placebo-controlled for atropine.

SETTING:

The inpatient psychiatric unit at a university medical center.

PATIENTS:

Forty-nine patients scheduled for ECT.

INTERVENTIONS:

Atropine 0.6 mg intravenously (IV) or an equal volume of normal saline IV was given before IV induction of anesthesia with methohexital 0.5 to 1.0 mg/kg, thiamylal 1.5 to 2.5 mg/kg, or thiopental sodium 1.5 to 2.5 mg/kg.

MEASUREMENTS AND MAIN RESULTS:

Single-lead electrocardiogram (ECG) recordings were made for 1 minute before induction, during induction of anesthesia, and for 5 minutes after the ECT stimulus. Each ECG was evaluated for arrhythmias and evidence of ischemia in a blinded fashion. Blood pressure and ECG evidence of ischemia did not differ among the groups. Seizure duration was significantly (p less than 0.05) prolonged by a mean of 5 seconds during methohexital anesthesia compared with thiopental sodium and thiamylal (47.6 +/- 18.6 seconds, 42.7 +/- 13.2 seconds, and 42.7 +/- 15.2 seconds, respectively). The frequency of sinus bradycardia was decreased (p less than 0.05) with methohexital (8%) compared with thiopental sodium (20%) and thiamylal (20%). The frequency of premature atrial contractions was decreased (p less than 0.05) with methohexital (43%) compared with thiamylal (61%) but not with thiopental sodium (57%). The frequency of premature ventricular contractions was decreased (p less than 0.05) with methohexital (27%) compared with thiopental sodium (44%) but not with thiamylal (40%). Atropine decreased the frequency of bradycardia (9% vs. 24%) and premature atrial contractions (47% vs. 61%) and increased the frequency of sinus tachycardia (88% vs. 75%).

CONCLUSIONS:

These data suggest that anesthesia for ECT therapy should be induced with methohexital to minimize the possibility of potentially life-threatening cardiac arrhythmias. Atropine premedication may further decrease the frequency of premature atrial contractions and bradycardia, while increasing the frequency of tachycardia.

• Authors: B K Mokriski, S E Nagle, G C Papuchis, S M Cohen, G J Waxman
• Journal: Journal of clinical anesthesia (J Clin Anesth) 1992 May-Jun Vol. 4 Issue 3 Pg. 208-12 ISSN: 0952-8180 [Print] United States
• PMID: 1610576 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Thiamylal
• Atropine
• Methohexital
• Thiopental

Topics

• Adult
• Aged
• Aged, 80 and over
• Anesthesia, General
• Arrhythmias, Cardiac (epidemiology, etiology)
• Atropine (administration & dosage)
• Double-Blind Method
• Electroconvulsive Therapy (adverse effects)
• Humans
• Injections, Intravenous
• Methohexital
• Middle Aged
• Preanesthetic Medication
• Thiamylal
• Thiopental