Comparing the first-pass success rate of oral intubation in patients who received or did not receive add-on topical lidocaine in the upper airway: A pilot randomized controlled trial

Abstract

The intubation with sedatives method is commonly employed by general practitioners in the emergency department (ED) in Thailand. This pilot study aimed to assess the feasibility of conducting a larger definitive trial on the first-pass success rate of oral intubation in patients who received or did not receive add-on topical lidocaine in the upper airway. This parallel two-arm pilot randomized controlled trial took place in the emergency department of Somdejphrajoataksinmaharaj Hospital, spanning from October 2022 to April 2023. Participants included patients aged 18 years and older with an indication for oral intubation with a laryngoscope, screened using eligibility criteria for enrollment. Patients were randomized and assigned to either of the two study arms through sealed envelopes. The control arm received oral intubation with or without sedation, while the intervention arm received topical lidocaine applied to the upper airway in addition to the therapy in the control arm. Feasibility was assessed based on the recruitment rate, adherence to group assignment, and data completeness. The primary outcome was the first-pass success rate, while secondary outcomes were peri-intubation complications. During this period, 259 patients were intubated in the ED, but 179 patients were excluded. A total of 80 patients were randomly assigned to each group, with 40 patients in the intervention arm and 40 patients in the control arm. The study achieved its recruitment rate goal within 6 months, and adherence to the protocol was 97.5%. However, data completeness fell below expectations at 91.3% compared to the target of 95.0%. The first-pass success rate was 72.5% in the intervention group and 60.0% in the control group (Difference 12.5%; 95% CI, 8.0-33.0). Peri-intubation desaturation below 90% was more prevalent in the intervention group, with 22.5% versus 10.0% in the control group (Difference 12.5%; 95% CI, 3.4-28.4). Some patients with oxygen saturation below 90% at the end of preoxygenation were enrolled. Physicians performing intubation found it challenging to administer lidocaine in a supine position to agitated and uncooperative patients. Conducting a larger sample size in the future study, which could reveal statistical differences in clinical outcomes, is feasible by modifying exclusion criteria, improving the data collection process, and refining the method of topical lidocaine administration.