To the Editor:
I read with great concern the recent editorial from Dr. Lee, the title of which provided a very strong message to the readers of ANESTHESIOLOGY: “Succinylcholine Should Be Avoided in Patients on Statin Therapy.”1The editorial was in reference to the article by Turan et al. from the Department of Outcomes Research at the Anesthesiology Institute at Cleveland Clinic in Cleveland, Ohio.2The Cleveland Clinic authors performed a well designed study and were correct when they concluded that despite statistically significant results, the difference on plasma myoglobin concentration attributed to the use of succinylcholine in patients taking statins was likely to be small and probably of limited clinical consequences.
Lee based the strong and conclusive title of his editorial on a hypothesis that the negative finding of Turan et al. 's study was probably due to the fact that subjects at high risk for the development of high myoglobin plasma concentrations were excluded from the protocol, and that the inclusion of those subjects would have led to different results. He specifically mentioned the elderly population as a particularly vulnerable group because of its limited functional reserve. Although only another well designed study will be able to answer this question, I hypothesize that, if pursued, the study will find similar results as the one found by Turan et al. Elderly patients are probably less prone to a possible combined effect of statin and succinylcholine, simply because they have less muscle mass. If this clinical effect in fact existed, we would been observing a pandemic of perioperative renal failure caused by myoglobinuria during the past several years, since statins are prescribed frequently for the elderly population undergoing surgical procedures in the United States,3and succinylcholine has not been contra-indicated in the same population. In contrast, postoperative myoglobinuria leading to kidney injury is not a common clinical entity, being only reported in few case reports that attributed inappropriate patient positioning as a possible cause.4
Scientific writing techniques teach us that certain parts of manuscripts are particularly powerful in conveying the manuscript's message, and the title is definitely one of them. This fact has led certain peer-reviewed journals to restrict the use of conclusive titles by authors in order to limit the influence of the author's conclusion on readers' conclusions. I personally believe that conclusive titles are important and should be allowed to point out important study results based on scientific evidence, but this was not the case in Lee's editorial.
If readers are mislead by the title of Lee's editorial, it could lead to a change in practice that may increase the use of high doses of rocuronium in substitution for succinylcholine, and certainly could create a favorable clinical setting for the widespread use of sugammadex. Despite early favorable safety studies, sugammadex lacks the several decades of clinical experience of succinylcholine, which were crucial to understand the safety profile of succinylcholine. This change in practice would substantially increase the market for sugammadex because of the high prevalence of statin use among surgical patients. I understand that Lee has demonstrated in a well designed, industry-sponsored study the beneficial reversal effects of sugammadex on rocuronium-induced neuromuscular block, compared with spontaneous succinylcholine,5and therefore he might have a negative personal experience with succinylcholine. This was further confirmed by Lee's suggestion that succinylcholine should be removed from the anesthesia practice: “After all, many inexpensive anesthesia drugs have been removed from anesthesia practice, why not succinylcholine?” Again, another strong statement, supported by not enough evidence. It is unknown if patients are willing to pay the cost of sugammadex in cases where high doses of rocuronium are used instead of succinylcholine. It is also unknown the effects high doses of rocuronium can have on operating room utilization costs in countries were sugammadex is still not available, such as the United States. Also important to note is that succinylcholine postoperative myalgias can be reduced by a number of low-cost interventions, such as the perioperative use of another cheap drug, lidocaine.6
Succinylcholine has been used for several decades by anesthesiologists. Although it has well established contraindications, such as in patients with a history of malignant hyperthermia and spine cord injury, it is also a cheap and highly efficacious drug with clear indications for its use by anesthesiologists. Based on the current literature, there is no evidence that succinylcholine should be avoided in patients receiving statins. There is evidence after Turan et al. 's study that succinylcholine is likely safe for otherwise healthy patients taking statins.