Effect of Tracheal Intubation Mode on Cuff Pressure During Retractor Splay and Dysphonia Recovery After Anterior Cervical Spine Surgery: A Randomized Clinical Trial.

Abstract

Prospective, randomized, double-blinded trial. The aim of this study was to investigate whether the mode of tracheal intubation affects intraoperative endotracheal tube cuff pressure on retractor splay and post-anterior cervical spine surgery (ACSS) voice outcome. The combination of endotracheal tube (ETT) and cervical retractors has been implicated in recurrent laryngeal nerve compression and neuropraxia after ACSS. The asymmetric position of the oroETT within the larynx, as being fixed distally by the cuff and proximally by taping on one side of the mouth, may contribute to unilateral vocal palsy. Adult patients undergoing ACSS were randomized to receive either nasotracheal or orotracheal intubation under anesthesia. The primary endpoint was the maximal endotracheal tube cuff pressure (ETCP) when the retractors were set up. After the maximal ETCPs were recorded, then ETCPs were controlled to less than 25 mmHg. Secondary endpoints were self-assessed hoarseness, pitch, and loudness of voice on postoperative days (PODs) 1, 2, 7, and 30. We equally allocated 110 patients to nasotracheal and orotracheal intubation. The maximal ETCP during retractor splay did not differ for both the means and distributions of pressure range. After the surgery, more patients in the nasotracheal intubation group reported none or mild change of voice than did the orotracheal intubation group on PODs 1 and 2, in terms of hoarseness, pitch, and loudness (P = 0.001, 0.001, and 0.005, respectively, on POD 1; P = 0.002, 0.003, and 0.011, respectively, on POD 2). Mixed model analysis demonstrated that patients with nasotracheal intubation had significantly lower dysphonia scores after surgery (estimate treatment effect: -1.62, P < 0.0001). Statistics was adjusted to exclude interaction with ETT sizes. The tracheal intubation modes did not affect ETCP during retractor splay. However, nasotracheal intubation had a beneficial effect on dysphonia recovery after ACSS. 2.