Effect of intraoperative neuromuscular blockade on postoperative sore throat and hoarseness in patients undergoing spinal surgery: a prospective observational study

Intraoperative neuromuscular blockade affects the resting tension between the vocal cords. We assessed the effect of neuromuscular blockade on postoperative sore throat and hoarseness following tracheal intubation in patients undergoing lumbar spinal surgery in the prone position. Altogether, 99 patients were included; 50 patients did not receive neuromuscular blockade, and 49 patients received moderate neuromuscular blockade during the maintenance of anesthesia. Neuromuscular blockade was performed depending on the use of intraoperative neurophysiological monitoring. The number of intubation attempts, time to achieve tracheal intubation, and duration of intubation were recorded accordingly. The incidence and severity of postoperative sore throat and hoarseness was assessed at 1, 6, and 24 h after surgery. The overall cumulative incidence of postoperative sore throat (60% vs. 59%, respectively; P = 1.000) and postoperative hoarseness (68% vs. 61%, respectively; P = 0.532) did not differ between the no neuromuscular blockade and moderate neuromuscular blockade. The incidence and severity of postoperative sore throat and hoarseness was also not different between the moderate and no neuromuscular blockade at each time point after surgery. Nevertheless, the incidences of postoperative sore throat and hoarseness were quite high. Further studies investigating strategies to alleviate them are warranted accordingly.