Rocuronium vs Succinylcholine in ECT: The Case of the Jammed Lock

Imagine a high-security vault. To open the heavy steel door, you must insert a specific key into the lock and turn it. Once the door opens, the vault is active. Now, suppose you need to perform heavy maintenance on the building—an earthquake simulation, perhaps—and you must ensure the door stays firmly shut so it doesn't swing open and hurt someone.

You have two ways to disable the lock.

First, you could jam a fake key into the mechanism. It fits, it turns, and it momentarily triggers the unlocking gears—clunk-whir-clunk—before snapping off and jamming the cylinder completely. The door is locked, but you triggered the mechanism to do it. Second, you could simply stick a piece of industrial chewing gum over the keyhole. The key can't get in. The lock never turns. The mechanism stays silent.

This is the fundamental difference between the drugs analysed in this study. The vault door is your muscle tissue. The maintenance work is Electroconvulsive Therapy (ECT). And the choice of how to lock that door is the debate of Rocuronium vs Succinylcholine in ECT.

The Mechanics of Rocuronium vs Succinylcholine in ECT

Succinylcholine (SCC) is the fake key. It is a 'depolarising' blocker. If you inject it, it mimics the body's natural activation signal. It fits the receptor, fires the muscle once—causing visible twitches or fasciculations—and then stays attached, keeping the muscle in a fatigued, locked state. It works fast. But that initial 'turning of the lock' is violent. It is why patients often wake up with myalgia (muscle pain) and headaches.

Rocuronium is the gum. It is a 'non-depolarising' agent. It sits on the receptor and does nothing but block the space. If the body tries to send a signal to contract, the signal bounces off. No twitching. No initial firing. Just silence.

Historically, doctors tolerated the 'jammed key' method because it wore off quickly. However, Rocuronium has a partner called Sugammadex. If Rocuronium is the gum, Sugammadex is a solvent designed to dissolve only that specific gum instantly. This allows doctors to reverse the paralysis on demand.

What the Data Shows

Researchers consolidated data from seven studies, covering over 500 patient sessions, to see if the 'gum and solvent' method (Rocuronium-Sugammadex or RS) could replace the 'jammed key' (SCC). They looked at three main things: how long the therapeutic seizure lasted, how fast the patient woke up, and how much pain they were in afterwards.

The results paint an interesting picture. When looking at all studies combined, the RS method was associated with longer seizure durations. In the context of ECT, a longer seizure is often linked to better therapeutic outcomes. However, we must be careful here. When the researchers isolated only the high-quality randomised controlled trials, this difference vanished, suggesting the drugs might be equal in this regard.

Regarding recovery time, the difference was negligible. Patients woke up and started breathing on their own at roughly the same speed regardless of the drug used. The real divergence appeared in side effects. Because Rocuronium does not trigger that initial muscle-twitching 'clunk', the analysis suggests it leads to fewer adverse events like myalgia. The 'gum' method is simply gentler on the machinery than the 'jammed key'.

While the study highlights that high heterogeneity (variability) in the data means we need larger trials to be certain, the implication is clear. The RS combination offers a feasible, and potentially kinder, alternative for keeping the vault door shut.