Topical lidocaine inhibits spasm during colonoscopy: a double-blind, randomized controlled trial (with video)

Abstract

Background and study aims Topical peppermint oil prevents intestinal spasm, but can cause rebound spasm. Lidocaine hydrochloride, a local anesthetic, may work as an antispasmodic by blocking Na + channels. The aim of this study was to investigate the effect of topical lidocaine on the inhibition of colonic spasm during colonoscopy, compared with peppermint oil. Patients and methods A randomized, controlled double-blind trial was conducted in an academic endoscopy unit. Patients requiring endoscopic resection were randomly allocated to colonoscopy with topical administration of lidocaine (n = 30) or peppermint oil (n = 30). Similar vials containing different solutions were randomly numbered. Allocation was made based on the vial number. The solution used and the vial number were not revealed during the study. Two endoscopists performed all procedures using midazolam, without anticholinergic agents. When a pre-selected lesion was identified, the solution in the assigned vial was dispersed and the bowel observed for 5 minutes. The primary endpoint was the duration of spasm inhibition, and a secondary endpoint was the occurrence of rebound spasm stronger than before dispersion. Results There were no significant differences in patient demographics. Spasm was inhibited in almost all patients in both groups, with a similar median duration (lidocaine 227 sec vs. peppermint 212.5 sec, P = 0.508). In contrast, rebound spasm occurred less frequently in the lidocaine group (lidocaine 7 % vs. peppermint 47 %, P = 0.001). There were no adverse events or symptoms associated with administration of the solutions. Conclusions The inhibitory effect of lidocaine is not superior to peppermint oil. However, lidocaine significantly decreases the frequency of rebound spasms.

Inhibitory effect of lidocaine on colonic spasm during colonoscopy: A multicenter double‐blind, randomized controlled trial

“…This multicenter, randomized, double‐blinded controlled trial clearly showed that lidocaine dispersion during colonoscopy inhibited colorectal spasm more effectively compared with normal saline (control). To our knowledge, this is the first description of a benefit of topical lidocaine during colonoscopy, with previous research showing equivalence to topical peppermint oil …”

“…). In our previous study, median latency to spasm inhibition was 43.5 s after lidocaine application; the anesthetic effect of lidocaine is 30–45 min in mucous membranes. We therefore chose 3 min of observation as the time to assess the inhibitory effect of lidocaine.…”

“…Findings from our double‐blind clinical trial suggest that topical administration of lidocaine inhibits the intestinal spasm induced by colonoscope movement, through blocking a feedback mechanism mediated by sensory nerves in the mucosal layer. We observed inhibition of spasm in almost all patients with lidocaine dispersion, but the effect was not superior to peppermint oil . Safety and blood levels of lidocaine have not previously been studied.…”

“…Prior to colonoscopy, eligible patients were randomly assigned to one of two groups: 20 mL of 2% lidocaine hydrochloride solution (LID group) or 20 mL of normal saline solution (NS group), both topically dispersed. Concentration of lidocaine hydrochloride solution was determined from our previous study . Randomization was blinded such that neither the patient nor the investigator knew which solution was being given.…”

“…Peppermint oil is also an antispasmodic agent applied by topical dispersion, and a possible alternative to systemic‐use agents . However, topical peppermint oil is limited by a rather short duration of effect and a high prevalence of rebound spasm . Repeated dispersion of peppermint oil does not work in most patients, and peppermint oil is not widely used.…”