Background: Vocal fold immobility (paresis or paralysis) from recurrent laryngeal nerve injury remains an important cause of morbidity after anterior cervical spine surgery. A maneuver involving endotracheal tube (ETT) cuff manipulation has been proposed to reduce its incidence. This study is a randomized, prospective, double-blind investigation to test the hypothesis that ETT cuff manipulation reduces the incidence of postoperative vocal fold immobility after anterior cervical spine surgery.
Methods: One hundred patients scheduled to undergo anterior cervical spine surgery were randomly assigned to one of two groups. After inducing general endotracheal anesthesia, patients in the intervention group had their ETT cuff pressures maintained at 20 mmHg or less. After placement of self-retaining retractors, the ETT cuff was deflated for 5 s and then reinflated. Patients in the control group had no further manipulation of their ETT once the cuff was inflated after intubation. Cuff pressures in both groups were recorded before skin incision (baseline) and after placement of self-retaining retractors (peak). Patients' vocal fold motion was evaluated by indirect laryngoscopy performed preoperatively and postoperatively. The examination was videotaped and reviewed by a blinded otolaryngologist. Postoperative vocal fold motion was graded as normal, paretic, or paralyzed.
Results: Complete data were available in 94 patients. The incidence of vocal fold paralysis was 3.2% (95% confidence interval, 0.7-9.4%). Cuff manipulation decreased ETT cuff pressure but did not reduce the incidence of vocal fold immobility (15.4% vs. 14.5%).
Conclusion: Endotracheal tube cuff deflation/reinflation and pressure adjustment do not reduce the incidence of vocal fold immobility in anterior cervical spine surgery.