Lidocaine lubricants for intubation-related complications: a systematic review and meta-analysis

Purpose Postoperative sore throat (POST) is a relatively common morbidity. Topical lidocaine lubricants have been proposed to prevent POST; however, their effectiveness remains uncertain. This meta-analysis aimed to evaluate the prophylactic effect of lidocaine lubrications against POST, cough, and hoarseness in adult patients after surgery. Methods Randomized-controlled trials from PubMed, Embase, the Cochrane Library, and the ClinicalTrials.gov registry that were published from inception until 26 March 2018 were included that compared the effectiveness of lidocaine lubricants with that of controls in preventing the incidence of overall POST and moderate to severe POST (POSTMS) at the first and 24th postoperative hour (POST-1h, POST-24h, POSTMS-1h, and POSTMS-24h). Postoperative cough and hoarseness at the 24th postoperative hour were also studied. Bias assessment and subgroup, sensitivity, and trial sequential analyses were also performed. Results Fourteen randomized-controlled trials ( n = 2146) were selected. The incidences of POST-1h and POST-24h were 41.1 % and 22.6 % for the lidocaine group, and 41.9% and 23.5% for the control group, respectively. No effect was found on any of the outcome measurements. The overall risk ratios were 1.11 (95% confidence interval [CI], 0.82 to 1.51) and 1.06 (95% CI, 0.37 to 3.02) for the incidence of POST-1h and POSTMS-1h, respectively; 0.99 (95% CI, 0.83 to 1.17) and 0.49 (95% CI, 0.16 to 1.50) for POST-24h and POSTMS-24h, respectively; and, 1.09 (95% CI, 0.71 to 1.66) and 0.91 (95% CI, 0.66 to1.24) for postoperative cough (PC)-24h and postoperative hoarseness (PH)-24h, respectively. Conclusion Lidocaine lubricants applied on the tips of endotracheal tube are not effective against the morbidities of POST, PC, and PH. Trial registration PROSPERO (CRD42017073259); registered 26 October, 2017.