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

Abstract

Patient: Female, 48-year-oldFinal Diagnosis: Major depressive disorderSymptoms: Depression and anxiety • loss of appetite • maniaMedication: —Clinical Procedure: Electroconvulsive therapySpecialty: Anesthesiology • PsychiatryObjective:Unusual or unexpected effect of treatmentBackground: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 (N2O) 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 N2O 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 (N2O) 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 N2O when home medications were optimized. There is limited literature on the use of N2O 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 N2O on seizure duration.Conclusions:Considering the pleasant odor, independent antidepressant activity, vasodilatory effect, low blood-gas partition coefficient, and minimal effect on respiration, N2O 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 N2O for use during ECT.