Effect of Total Intravenous Anesthesia on Postoperative Pulmonary Complications in Patients Undergoing Microvascular Reconstruction for Head and Neck Cancer

Abstract

Free flap surgery is a lengthy procedure with massive tissue destruction and reconstruction, which makes postoperative pulmonary complications (PPCs) a noticeable issue among patients with head and neck cancer. Propofol-based total intravenous anesthesia (TIVA) has better survival outcomes than inhalational anesthesia (INH) in several types of cancer surgery. A previous retrospective study found that patients in the TIVA group had a lower PPC rate, which may be correlated with a lower intraoperative fluid requirement. We hypothesize that the protective effect remains among patients undergoing free flap surgery for head and neck cancer in a prospective and goal-directed fluid therapy setting. To assess the effect of TIVA vs INH on PPCs in patients undergoing microvascular reconstruction for head and neck cancer. This prospective, 2-arm, randomized clinical trial was conducted at a tertiary hospital in Taiwan; a total of 78 patients 18 years and older with American Society of Anesthesiologists physical status classification 1 to 3 who were scheduled for elective free flap surgery under general anesthesia were included. The trial started in October 2017, completed in October 2019, and finished analysis in January 2022. Patients were enrolled and randomized to the TIVA or INH group. All patients received goal-directed fluid therapy and hemodynamic management if they had a mean arterial pressure (MAP) below 75 mm Hg or a reduction of 10% from baseline MAP. The primary outcome was a composite of PPCs. The secondary outcomes were the differences in intraoperative hemodynamic values (mean arterial pressure, MAP; cardiac index, CI; systemic vascular resistance index, SVRI; and stroke volume variation, SVV). A total of 70 patients (65 men [93%]; 5 women [7%]) completed the trial; median (IQR) age was 52.0 (48-59) years in the TIVA group and 57.0 (46-64) years in the INH group. The demographic characteristics were similar between the 2 groups, except that patients in the TIVA group had a slightly lower body mass index. Patients in the TIVA group had a lower risk of developing PPCs (unadjusted odds ratio, 0.25; 95% CI, 0.08-0.80). The TIVA group had significantly higher MAP, lower CI, and higher SVRI than the INH group after the third hour of monitoring. The TIVA group showed a relatively stable hourly MAP, CI, SVRI, and SVV across time points, while the INH group showed a more varying pattern. The generalized estimating equation showed no clinical differences in the trend of hemodynamic parameters across time between groups. In this randomized clinical trial, using propofol-based TIVA reduced the incidence of PPCs in free flap surgery. This finding may be related to more stable hemodynamic manifestations and a lower total balance of fluid throughout the surgery. ClinicalTrials.gov Identifier: NCT03263078.