Point-of-Care Tongue Ultrasound for Perioperative Risk Stratification in Metabolic Bariatric Surgery

Patients undergoing metabolic bariatric surgery (MBS) have a high prevalence of obstructive sleep apnea (OSA), increasing the risk of postoperative respiratory complications. While tongue thickness has been linked to OSA severity, its role as a predictor of postoperative hypoxemia and other complications remains unclear. This study is the first to evaluate whether preoperative ultrasound-measured tongue thickness correlates with postoperative respiratory outcomes and complications in patients undergoing MBS.  METHODS: This prospective observational cohort study included 119 adult patients undergoing robotic-assisted laparoscopic MBS. Preoperative point-of-care ultrasound was used to measure sagittal and coronal tongue thickness. Continuous postoperative monitoring was performed using the Masimo RAD-97™ system for up to 14 h. Outcomes included desaturation events, respiratory and pulse events, and 30-day postoperative complications. Correlations between tongue thickness and clinical outcomes were analyzed and stratified by OSA status.

Larger tongue dimensions were modestly associated with postoperative desaturation events. Significant time-dependent correlations were observed during the 0-6-h postoperative period (ρ = 0.15-0.34). Patients with OSA showed correlations with desaturations during the first 2 h, while patients without OSA had associations during the 4-6-h window. There were no significant differences in tongue size for those with common 30-day complications (p > 0.05).

Ultrasound-measured tongue thickness is associated with early postoperative oxygen desaturation in patients undergoing MBS, independent of OSA diagnosis. These findings suggest that tongue ultrasound may serve as a noninvasive tool for preoperative respiratory risk stratification. Further studies into comprehensive preoperative anatomical measurements to enhance risk stratification are warranted.