Effect of ultrasound-guided superior laryngeal nerve block on tracheal tube-related responses during postoperative recovery in craniotomy patients: a randomized controlled trial

Background: Coughing and hemodynamic fluctuations during emergence from anesthesia after a craniotomy can result in serious complications. This study evaluated whether the ultrasound-guided superior laryngeal nerve block (SLNB) attenuates these tracheal tube-related responses. Methods: Eighty patients scheduled for elective craniotomy were randomized into the control (Group C, 2 ml 0.9% saline per side) and SLNB (Group S, 2 ml 1% lidocaine per side) group. The primary outcome was the incidence of coughing during the recovery period. Secondary outcomes included the severity of coughing, hemodynamic fluctuations, need for rescue interventions, anesthesia-related parameters, and complications. Results: Compared to controls, the patients in Group S experienced a significantly reduced incidence (78.9% vs. 48.6%; P = 0.006) and severity (P < 0.001) of coughing during emergence. The mean arterial pressure and heart rate were also more stable during and after extubation in Group S than in Group C. Furthermore, Group S required a significantly lower dose of nicardipine during the emergence period (P = 0.032), and both the incidence of and visual analog scale (VAS) scores for postoperative sore throat at 6 h after extubation were markedly reduced (P = 0.035). No significant differences were noted between the groups in terms of propofol consumption, emergence agitation, extubation time, post-anesthesia care unit stay duration, or complications. Conclusions: The SLNB significantly suppressed extubation-related responses during anesthetic emergence after craniotomy by reducing coughing and attenuating hemodynamic fluctuations, thereby contributing to a smoother emergence profile.