Risk stratification for postoperative hypoxemia among bariatric surgery patients

Patients with obesity, especially those suffering from obstructive sleep apnea (OSA), are prone to postoperative respiratory hypoxemia. The PRODIGY (prediction of opioid-induced respiratory depression in patients monitored by capnography) Score is used to predict respiratory complications that factor in sleep-disordered breathing. Data on the impact of OSA on the frequency and timing of postoperative desaturation trends after bariatric surgery are lacking.

This cohort study included 195 patients who underwent robotic-assisted bariatric surgery between June 2022 and December 2023. Patients underwent were classified by OSA status (yes/no) and PRODIGY Risk Score (high/intermediate/low). All patients received low or opioid sparing anesthesia and were continuously monitored postoperatively using the Masimo Rad-97 device (Masimo, Irvine, CA, USA). Postoperative monitoring averaged 14.5 hours, including tracking several variables and SpO2 values. We documented desaturations and opioid usage in 2-hour intervals. Patients also underwent 30-day postoperative follow-up. Descriptive statistics were analyzed based on OSA status and PRODIGY scores using Student's t-test, ANOVA, and Fisher's Exact Test.

Most study patients (57.4%) had OSA, were significantly older, and were predominantly female. Patients with OSA had substantially more prolonged exposure to SpO2 ranges between 80-95% and experienced more frequent desaturation events between 10 and 14 hours after Post-Anesthesia Care Unit (PACU) discharge. Patients with high PRODIGY scores (>15) had significantly more desaturation events compared to intermediate and low-score groups.

Postoperative desaturation rates are significantly higher among patients with OSA with high PRODIGY scores, especially in the delayed postoperative period. Continuous extended postoperative monitoring is warranted for these high-risk patients after bariatric surgery.