Postoperative Sore Throat Helps Predict Swallowing Disturbance on Postoperative Day 30 of Anterior Cervical Spine Surgery: A Secondary Exploratory Analysis of a Randomized Clinical Trial of Tracheal Intubation Modes

Nasotracheal intubation benefits dysphonia recovery after anterior cervical spine surgery (ACSS). The aim of the present study was to investigate the effect of tracheal intubation modes on post-ACSS swallowing function and identify factors associated with deglutition on postoperative day 30 (POD 30). Adult patients were randomized to receive either nasotracheal or orotracheal intubation during surgery. A numerical rating scale (NRS) was used to assess postoperative sore throat, and the Bazaz grading system was used to assess the severity of swallowing disturbance. The primary endpoints were the effect of tracheal intubation modes on postoperative sore throat and deglutition. Thereafter, we further elucidated the predictors of swallowing disturbance on POD 30. Postoperative sore throat and swallowing disturbance did not differ between the nasotracheal and orotracheal intubation groups. A secondary dataset analysis revealed that among 108 patients with complete follow-up until POD 30, 71 (65.7%) presented complete recovery without swallowing disturbance, whereas 37 (34.3%) presented varying degrees of swallowing disturbance. Receiver operating characteristic curve analysis indicated that the NRS score for sore throat predicted a swallowing disturbance-free status on POD 30. The optimal cutoff values were ≤ 4 and ≤ 2 on PODs 1 and 2, respectively. The adjusted odds ratio (OR) for independent predictors was a sore throat NRS score of ≤ 4 on POD 1 (OR 3.2; 95% CI 1.29–7.89; P = 0.012) and score of ≤ 2 on POD 2 (OR 6.67; 95% CI 2.41–18.47; P < 0.001). Therefore, tracheal intubation mode did not affect the incidence of post-ACSS swallowing disturbance, and the severity of sore throat on PODs 1 and 2 could predict a swallowing disturbance-free status on POD 30. The trial was registered at clinicaltrials.gov (Trial No. NCT03240042, date of registration 10/17/2017).