Neuromuscular blockade is required to control excessive muscle contractions during electroconvulsive therapy (ECT). In a crossover, assessor-blinded, prospective randomized study, we studied the minimum effective dose (MED) of succinylcholine and rocuronium for ECT. The MED was the lowest dose to provide a predefined qualitative measure of acceptable control of muscle strength during induced convulsions.
Succinylcholine (0.8 mg kg−1) or rocuronium (0.4 mg kg−1) was randomly administered in 227 ECT sessions to 45 patients. The dose was incrementally increased or decreased by 10% based on 2 psychiatrists’ (blinded to treatment) assessment of “acceptable” or “not acceptable” control of evoked muscle contractions (sufficient versus insufficient or excessive paralysis). The neuromuscular transmission was monitored quantitatively until full recovery.
In our study, the MEDs of succinylcholine and rocuronium to produce acceptable ECT conditions in 50% of patients (MED50ECT) were 0.85 mg kg−1 (95% confidence interval [CI], 0.77–0.94) and 0.41 mg kg−1 (95% CI, 0.36–0.46) and in 90% of patients (MED90ECT) were 1.06 mg kg−1 (95% CI, 1.0–1.27) and 0.57 mg kg−1 (95% CI, 0.5–0.6), respectively. Nadir twitch height for acceptable muscle activity was 0% (0–4) and 4% (0–30; P < 0.001), respectively, and the time to recovery of the neuromuscular transmission was 9.7 ± 3.5 and 19.5 ± 5.7 minutes, respectively.
A twitch suppression of >90% is needed for control of motor contractions during ECT. The initial ECT dose of succinylcholine should be selected based on each patient’s preprocedural condition, ranging between 0.77 and 1.27 mg kg−1 to produce acceptable muscle blockade in 50% to 90% of patients. Rocuronium–neostigmine combination is a safe alternative if appropriately dosed (0.36–0.6 mg kg−1) and monitored.
Supplemental Digital Content is available in the text.Published ahead of print March 10, 2016
From the *Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; †Broad Institute of MIT and Harvard, Cambridge, Massachusetts; ‡Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts; §Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden University, Leiden, The Netherlands; ‖Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; ¶Patient Care Services/Special Care Nursery, Massachusetts General Hospital, Boston, Massachusetts; and #Clinic for Anesthesiology and Intensive Care, Essen University Hospital, Essen, Germany.
Accepted for publication December 18, 2015.
Published ahead of print March 10, 2016
Conflict of Interest: See Disclosures at the end of the article.
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This report was previously presented, in part, at the IARS 2012 meeting, Boston, Massachusetts.
Reprints will not be available from the authors.
Address correspondence to Hooman Mirzakhani, MD, PhD, MMSc, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114. Address e-mail to email@example.com.