Improving safety and effectiveness of awake endotracheal intubation with a novel method: A prospective, double-blind, randomized controlled trial

Background: Topical anesthesia is a crucial step in awake endotracheal intubation for providing favorable intubation conditions. The standard of care technique for awake intubation, which consists of oropharyngeal tetracaine spray, can result in inadequate mucosal anesthesia. Therefore, we sought to compare the effectiveness of dyclonine hydrochloride mucilage to the standard of care tetracaine in achieving anesthesia of the upper airways for awake endotracheal intubation. Methods: This randomized, double-blind, prospective study included 60 patients scheduled for either endoscopic submucosal dissection or peroral endoscopic myotomy. Patients were randomly allocated into two groups: patients allocated to novel awake intubation care (Group N-AIC) received a single administration of oral dyclonine hydrochloride mucilage, whereas patients allocated to standard awake intubation care (Group S-AIC) received three oropharyngeal tetracaine sprays before transcricoid tetracaine injection before awake intubation. Feeling of numbness and nausea, as well as intubation conditions after topical anesthesia were assessed. Hemodynamic parameters were recorded throughout the procedure and compared between the two groups. Results: The degree of numbness of the oropharynx mucosa after topical anesthesia did not differ between the two groups, neither did the feeling of nausea during laryngoscopy. The amount of pharyngeal secretions before intubation was less in Group N-AIC. Total intubation time was significantly shorter (3.9s, 95%CI 1.282-6.452, P=0.004) in Group N-AIC. Baseline mean arterial pressure and heart rate were similar between the two groups. Hemodynamic responses to intubation and gastrointestinal endoscopy, especially mean arterial pressure, were significantly less elevated in Group N-AIC. Extubation bucking was significantly less frequent in Group N-AIC (13.3% vs. 76.7%). Patients received in Group N-AIC had a lower rate of post-extubation sore throat compared to Group S-AIC (6.7% vs. 43.3%). No adverse side effects attributable to either tetracaine or dyclonine were observed in this study. Conclusions: In awake endotracheal intubation, novel care using oral dyclonine hydrochloride mucilage can provide more favorable intubation conditions and more stable hemodynamics compared to standard of care practice using oropharyngeal tetracaine spray. Chinese Clinical Trial Registry: ChiCTR1900023151 ( http://www.chictr.org )