Rocuronium-Sugammadex vs Succinylcholine in ECT: A Strategic Safety Dossier

Problem: The Depolarising Risk

Electroconvulsive therapy (ECT) relies on varying degrees of muscle relaxation to prevent physical injury during seizure induction. For decades, succinylcholine (SCC) has served as the standard agent. It is cheap, fast, and reliable. However, its mechanism—depolarising neuromuscular blockade—is crude. It forces muscles to contract before relaxing, creating a cascade of physiological stress.

Patients frequently report severe myalgia. Clinicians must manage risks of hyperkalaemia and increased intraocular pressure. In specific populations, such as those with burns or neuromuscular disorders, SCC is absolutely contraindicated. The clinical need is urgent: a relaxant that mirrors the speed of SCC but eliminates its toxicity. This dossier analyses the efficacy of Rocuronium-Sugammadex vs Succinylcholine in ECT to determine if the challenger can replace the incumbent.

Rocuronium-Sugammadex vs Succinylcholine in ECT: The Solution

The rocuronium-sugammadex (RS) protocol represents a fundamental shift in anaesthetic strategy. Rocuronium provides a non-depolarising block, avoiding initial muscle fasciculation. Sugammadex, a cyclodextrin, acts as a selective relaxant binding agent. It encapsulates the rocuronium molecule, chemically removing it from the neuromuscular junction. This provides active, rather than passive, reversal.

The meta-analysis aggregated data from seven studies, covering 250 RS observations and 282 SCC sessions. The objective was to measure if RS could match the recovery speed of SCC while maintaining adequate seizure duration.

Mechanism: Data and Variance

The study measured two primary performance metrics: seizure duration and time to spontaneous respiration.

Seizure Duration: Effective ECT requires a seizure of adequate length. In the pooled analysis, RS was associated with a statistically longer motor seizure duration (SMD: 0.43). This is a positive marker for therapeutic efficacy. However, when the analysis was restricted strictly to randomised controlled trials, this advantage disappeared (SMD: 0.54, 95% CI: -0.17 to 1.25), suggesting functional equivalence between the two agents.

Recovery Velocity: The data regarding recovery time is complex. The pooled Standardised Mean Difference was -0.51, indicating no statistically significant difference between RS and SCC. However, the heterogeneity was massive (I² > 89%). This variance likely stems from inconsistent dosing protocols. Unlike SCC, which metabolises at a fixed rate, RS recovery depends entirely on the dose of sugammadex administered. Some trials likely under-dosed the reversal agent, skewing the data.

Impact: The Safety Dividend

The primary utility of the RS protocol lies in the side-effect profile. Qualitative data from the reviewed studies indicates a reduction in adverse events, specifically myalgia. For patients undergoing maintenance ECT, reducing physical pain is critical for long-term adherence to the programme.

For the anaesthetist, RS offers control. SCC forces a 'wait-and-see' approach; RS allows for immediate reversal in airway emergencies. While RS is costlier, the reduction in patient discomfort and the expansion of safety margins for high-risk patients justifies the expense. The study suggests that RS is a feasible alternative, but clinical teams must standardise sugammadex ratios to ensure predictable recovery times.