Written by Amanda Mathews
This retrospective cohort study found no 24-hour mortality difference when intubating hyperkalemic patients (K > 5.5mmol/L) with succinylcholine versus rocuronium for RSI.
Caught between a roc and a hyperkalemic place
When conducting rapid sequence intubation (RSI) in the ED, paralytic options include the depolarizing agent succinylcholine and the non-depolarizing agent rocuronium. Both have benefits and risks, and hyperkalemia is often cited as a contraindication for succinylcholine use. While we know that there is a transient increase in serum potassium of 0.3–1.0 mmol/L for 10–15 minutes after giving succinylcholine, only case reports have shown any adverse events related to this potassium increase. This retrospective cohort study included 434 patients ≥ 18 years who had serum K > 5.5 mmol/L and required RSI with either agent (310 rocuronium; 124 succinylcholine). Primary outcome was 24-hour mortality, and secondary outcome was cardiac arrest within 1 hour of paralytic administration. Mean initial potassium level was 6.3 mmol/L in the rocuronium group and 6.4 mmol/L in the succinylcholine group.
There was no statistically significant difference in 24-hour mortality between groups: 10% rocuronium; 10.5% succinylcholine. The secondary outcome of cardiac arrest within 1 hour was low overall, with only 7 patients (1.6%) having a cardiac arrest. Six of the seven arrests within one hour of RSI were in the rocuronium group. There was no way to gauge first-pass success rate retrospectively.
How will this change my practice?
Much like the great ketamine/etomidate debate, many clinicians have strong feelings about which paralytic to use in RSI. There are clear risks and benefits to both succinylcholine and rocuronium, but this study calls into question whether hyperkalemia should be considered a hard and fast contraindication to using succinylcholine. I wonder if the risk of awake paralysis (more common with rocuronium) is actually higher at this point than the risk of a hyperkalemic cardiac arrest. I will not start using succinylcholine indiscriminately (especially in patients who need more frequent neuro checks), but I will feel more comfortable using this paralytic with unknown potassium levels or in already hyperkalemic patients.
Source
Hyperkalemic emergency department patients intubated with rocuronium or succinylcholine: Retrospective study of clinical outcomes. Am J Emerg Med. 2025 Dec 2;100:154-164. doi: 10.1016/j.ajem.2025.11.030. Epub ahead of print. PMID: 41380422.
