Risk factors for elevated endotracheal tube cuff pressure in anterior cervical spine surgery.

Abstract

Dysphonia resulting from injury to the recurrent laryngeal nerve (RLN) is a known risk of anterior cervical spine surgery (ACSS). While the main mechanism underlying this injury is unclear, high endotracheal tube (ETT) cuff pressures have been linked to postoperative dysphonia. This study was performed to assess intraoperative ETT cuff pressures and how patient and surgical variables influence them. A retrospective observational study was conducted using intraoperative cuff pressures collected from patients who underwent ACSS from January 2024 to March 2025 at a single institution. ETT cuff pressure was measured after intubation, manual adjustment, and, finally, placement of cervical retractors. Data for 3 months after surgery were collected via retrospective chart review. Additionally, 5 cadaveric specimens were obtained for experimentation. After intubation of a specimen, cuff pressure was set to 20-30 cm H2O and remeasured following cervical retraction. Among the 39 patients included in the study, ETT cuff pressures at the start of surgery often exceeded safe levels, with a mean pressure of 72.6 ± 37.7 cm H2O (IQR 81). These elevated levels were significantly associated with obesity and female sex. Despite manual adjustment, ETT cuff pressures were again elevated following airway retraction, with a mean of 50.5 ± 19.9 cm H2O (IQR 31.5). Cuff pressures were also increased with caudal surgery and an advanced age. A cadaveric model demonstrated that caudal cervical approaches, as compared to rostral ones, yielded a significantly greater increase in ETT cuff pressure following retraction (p < 0.0001). The side of approach was not a significant determinant of pressure elevation at either cervical level of approach. Retraction of cervical tissues during ACSS significantly increases ETT cuff pressure to unsafe levels, increasing the risk of RLN injury. Frequent ETT cuff pressure monitoring and adjustment are necessary to reduce RLN exposure to elevated pressures and potentially reduce the risk of dysphonia after ACSS.