Use of Nitrous Oxide to Facilitate Induction for Electroconvulsive Therapy: A Case Report

Patient: Female, 48-year-old Final Diagnosis: Major depressive disorder Symptoms: Depression and anxiety • loss of appetite • mania Medication: — Clinical Procedure: Electroconvulsive therapy Specialty: Anesthesiology • Psychiatry OBJECTIVE: Unusual or unexpected effect of treatment BACKGROUND: The choice of pharmacologic agents used for electroconvulsive therapy (ECT) is critical as this can affect seizure duration and, ultimately, the effectiveness of ECT for the underlying condition. We report the use of nitrous oxide (N(2)O) to sedate and place an intravenous (IV) catheter in a combative patient for the induction of anesthesia. We found no significant clinical effect on seizure duration while using N(2)O in the pre- and intra-procedural period. CASE REPORT: We present the case of a 48-year-old woman with a history of major depressive disorder scheduled for electroconvulsive therapy (ECT). We used 50% nitrous oxide (N(2)O) to sedate her and facilitate the placement of a 22-gauge IV catheter. When IV access was established, induction of anesthesia was done with 80 mg of methohexital, which was later switched to 16 mg of etomidate and 80 mg of succinylcholine. After multiple ECT treatments, we observed no significant clinical effect on seizure duration while using N(2)O when home medications were optimized. There is limited literature on the use of N(2)O as a sedative agent in the perioperative period with other agents known to have no effect or beneficial effect on ECT treatments. We found no studies assessing the effect of N(2)O on seizure duration. CONCLUSIONS: Considering the pleasant odor, independent antidepressant activity, vasodilatory effect, low blood-gas partition coefficient, and minimal effect on respiration, N(2)O may serve as the ideal adjunct to intravenous induction of anesthesia in an uncooperative or anxious patient. Further studies are warranted to confirm the efficacy and the safety of N(2)O for use during ECT.