Short-Term Voice Changes After Endotracheal Intubation: Comparative Study of Head/Neck and Abdominal Surgery

Background/Objectives: Endotracheal intubation can cause postoperative voice disturbances, even after short procedures. These effects have been documented in head and neck surgery, but direct comparisons between head/neck and abdominal surgeries are lacking. We sought to compare short-term postoperative voice changes in patients undergoing head/neck and abdominal surgery and to evaluate their association with intubation parameters and patient factors. Methods: We prospectively studied 80 adults (mean age X ± SD) undergoing either head-neck surgery (parotidectomy or total thyroidectomy) or abdominal surgery. Voice acoustic parameters (fundamental frequency (F₀), jitter, shimmer, intensity, maximum phonation time (MFT)) were measured preoperatively and on postoperative days 2, 14, and 30. Anesthetic parameters were recorded during the perioperative period. Anesthesiologists were blinded to the ongoing investigation. We used repeated-measures ANCOVA (with sex as a covariate) to test for group-by-time interactions and main effects. Effect sizes were calculated. Results: Eighty patients were included. All acoustic parameters showed significant postoperative changes (p < 0.001). The most pronounced alterations occurred in the early postoperative period, with decreased F₀, intensity, and MFT, and increased jitter and shimmer. Significant interaction effects between time and type of surgery were observed for F₀ (ηp² = 0.445), shimmer (ηp² = 0.210), intensity (ηp² = 0.267), and MFT (ηp² = 0.149), indicating distinct recovery patterns across groups. Patients undergoing abdominal surgery showed less pronounced and more rapidly resolving changes, whereas head and neck surgery was associated with greater and more persistent impairment. Among all parameters, shimmer demonstrated the largest overall effect size (ηp² = 0.338), suggesting high sensitivity to short-term voice changes. Perioperative factors, including duration of surgery, endotracheal tube size, and BMI, were significantly associated with the extent of voice changes. Conclusions: Short-duration endotracheal intubation can lead to measurable short-term voice changes, which are more pronounced after head/neck surgery (particularly total thyroidectomy). Objective acoustic analysis detected these subclinical alterations even when patients were asymptomatic. These findings underscore the importance of monitoring voice outcomes and optimizing intubation techniques, although future work is needed to correlate acoustic changes with laryngeal exam findings.