We read with great interest the April 2022 Monitor article by Hardman et al. that evaluated the use and reliability of rocuronium and succinylcholine as rapid-onset neuromuscular blocking agents (NMBAs) during induction (ASA Monitor 2022;86:42). The authors appropriately discuss the inverse relationship between the molar potency of NMBAs and their speed of onset. However, we question the authors' statement that given the low potency of rocuronium, there appears to be a significant variability in its onset and duration.
First, can the variability of rocuronium onset and duration be explained by a cause-and-effect relationship with its low potency? The authors mention that succinylcholine appears to share this relationship as well. We are not aware of evidence to back either claim. The two cited papers purporting to support this idea do not relate low potency to variability of action of NMBAs. Indeed, a potency-onset effect for NMBAs is not easily...
