DP46: OPTIMIZING NEUROMUSCULAR BLOCKADE IN ELECTROCONVULSIVE THERAPY: A TARGETED APPROACH TO ENHANCE RECOVERY AND REDUCE DELIRIUM IN A PATIENT WITH AN ELEVATED BMI.
Benjamin Cipion, MS; Ryanne Thelwell, BS; Brent R Carr, MD; R. Victor Zhang, MD, PhD
University of Florida College of Medicine
Introduction: General anesthesia (GA) plays a crucial role in electroconvulsive therapy (ECT), ensuring hemodynamic stability, amnesia, and muscle relaxation to minimize the risk of injury from seizure-induced convulsions. GA for ECT typically involves methohexital for sedation and succinylcholine (SCh) for neuromuscular blockade. However, patients with an elevated BMI face heightened anesthesia-related risks due to reduced oxygen reserves and increased risk for airway obstruction. The conventional SCh dosing of 1 mg/kg total body weight (TBW) may lead to excessive paralysis, prolonged airway obstruction, and respiratory distress, often resulting from hypercapnia rather than hypoxia. This case underscores the advantages of ideal body weight (IBW) based SCh dosing in a patient with an elevated BMI who experienced post-procedural agitation due to respiratory discomfort following standard dosing.1-3
Case Description: A middle-aged female with a BMI of 35 underwent multiple ECT sessions for treatment-resistant psychiatric illness. During her initial four treatments, she developed agitation, sensations of suffocation, and presumed delirium upon awakening. These episodes necessitated rescue sedation, prolonging her recovery with increased anesthesia-related risks. Recognizing potential SCh overdose, her anesthesia plan was reevaluated. At a dose of 1 mg/kg TBW (100 mg), she exhibited signs of prolonged weakness, contributing to post-procedural air hunger. Her SCh dose was subsequently decreased to 1 mg/kg IBW (50 mg). This adjustment provided effective neuromuscular blockade while significantly shortening her recovery, alleviating sensations of suffocation, and minimizing the need for rescue sedation in subsequent ECT sessions.
Discussion: Transitioning from TBW-based to IBW-based SCh dosing reduced respiratory discomfort and facilitated smoother post-anesthesia recovery. Standard TBW-based dosing can cause excessive paralysis in patients with an elevated BMI, as drug distribution does not scale proportionally with body weight. These individuals already face more significant risks under GA due to diminished oxygen reserves and a tendency of upper airway collapse, increasing susceptibility to hypercapnia and associated distress.3,4
Unlike typical SCh overdose cases characterized by oxygen desaturation, this patient maintained normal oxygenation but experienced CO2 retention. Her body habitus contributed to respiratory mechanics that exacerbated air hunger and agitation upon emergence. By tailoring SCh dosing to IBW, the duration of paralysis was reduced, mitigating hypercapnia and enhancing the overall post-anesthesia experience.3,4
This case highlights the significance of individualized neuromuscular blockade strategies for patients with an elevated BMI. Given the altered pharmacokinetics in this population, IBW-based dosing aligns more closely with drug distribution, diminishing the likelihood of prolonged paralysis and airway obstruction, excessive sedation, and post-procedural distress.1,3
Conclusion: Standard TBW-based SCh dosing in ECT may not be appropriate for patients with an elevated BMI, as it can extend neuromuscular blockade and hinder respiratory function. Adjusting the dose to IBW improved this patient's recovery, eliminating post-procedural distress and decreasing the need for additional sedation. These findings support a more individualized approach to SCh dosing in ECT to enhance patient safety and optimize recovery. Further research is necessary to refine dosing protocols and improve anesthesia outcomes in this demographic.
References:
1. Cureus 2024;16(7):e65654
2. Anesth Analg 1999;89(5):1301-4
3. Anesth Analg 2006;102:438-42
4. Saudi Med J 2018;39(1):103-6