Superior Laryngeal Nerve Block for Microlaryngoscopic Surgery: A Systematic Review and Meta‐Analysis

Objectives To assess the safety and efficacy of superior laryngeal nerve block (SLNB) for microlaryngoscopic surgery (MLS). Data Sources PubMed, Embase, Web of Science, Ovid Medline, Cochrane Library, CNKI database, VIP database, Wanfang database, and trial registry databases. Methods PICOS principles were performed: adults undergoing MLS receiving SLNB compared with no‐SLNB in randomized controlled trials were included. Primary outcome included the incidence of severe postoperative sore throat (POST). Secondary outcomes included perioperative mean arterial pressure (MAP) and heart rate (HR), incidence of severe postoperative cough, and anesthesia recovery time. Results Eleven articles with 728 patients were included. Results indicated that SLNB provides lower incidence of severe POST in post‐extubation 30 min (relative ratio [RR] = 0.13; 95% confidence intervals [CIs]: 0.05 ~ 0.34), 2 h (RR = 0.09; 95% CI: 0.02 ~ 0.36), 4–6 h (RR = 0.11; 95% CI: 0.03 ~ 0.41), and 24 h (RR = 0.15; 95% CI: 0.03 ~ 0.83); lower MAP (tracheal intubation: standardized mean difference [SMD] = −1.59; 95% CI: −1.69 to −0.42); suspension laryngoscope insertion: (SMD = −0.98; 95% CI: −1.49 to −0.46); tracheal extubation: (SMD = −0.78; 95% CI:−1.24 to −0.31); post‐extubation 5 min: (SMD = −0.95; 95% CI: −1.41 to −0.49); lower HR (tracheal intubation: mean difference [MD] = −9.71; 95% CI: −17.16 to −2.27); suspension laryngoscope insertion: (MD = −8.64; 95% CI: −16.79 to −0.49); tracheal extubation: (MD = −10.13; 95% CI: −17.86 to −2.39); post‐extubation 5 min: (MD = −13.44; 95% CI: −22.53 to −4.35); lower incidence of severe postoperative cough in post‐extubation 30 min (RR = 0.18; 95% CI: 0.06 ~ 0.57) and 2 h (RR = 0.13; 95% CI: 0.02 ~ 0.69); and shorter anesthesia recovery time (MD = −5.34; 95% CI: −8.81 to −1.86) compared to controls. Conclusions SLNB could provide lower incidence of severe POST, more stable perioperative MAP and HR, lower incidence of severe postoperative cough, and shorter anesthesia recovery time for MLS. Level of Evidence I Laryngoscope , 134:3437–3446, 2024