Buffered Lidocaine for Topical Nasal Anesthesia: A Double-Blind Randomized Controlled Trial

Transnasal fiberoptic laryngoscopy (TFL) is frequently performed by otolaryngologists, for which lidocaine spray is one of the standard options for preprocedural local nasal anesthesia. The combination of lidocaine with bicarbonate has not been tested intranasally despite reported success in reducing pain in local skin injections, emergency medicine, and dentistry. This study investigates the effectiveness and side effects of local nasal anesthesia carried out with buffered lidocaine compared with plain lidocaine.

Double-blind, randomized controlled trial.

Seventy patients undergoing TFL examination were enrolled in the study. The plain lidocaine group included 35 patients treated with lidocaine 5% intranasal spray. The buffered lidocaine group included 35 patients treated with a mixture of lidocaine 5% with bicarbonate 8.4%. Following the TFL examination, patients were asked to rate pain severity on the visual analog scale (VAS) and their side effects on a 10-point scale.

The buffered lidocaine group had a lower average VAS score (1.97 ± 1.74) than the plain lidocaine group (2.23 ± 1.63), although the difference was not significant (95% CI -0.329 to 0.148; P = 0.45). The plain lidocaine group had significantly lower topical burning sensation (95% CI 0.247 to 0.651; P < 0.001), throat discomfort (95% CI 0.179 to 0.588; P = 0.001), and headache (95% CI 0.12 to 0.368; P = 0.04). No significant difference was found between the groups on any of the other parameters.

Topical nasal anesthesia with plain lidocaine demonstrated a better side effects profile than buffered lidocaine without a significant difference in local anesthesia.