Gastric <scp>POCUS</scp> as a Perioperative Risk Assessment Tool in Hospitalized Patients Receiving Methadone for Opioid Use Disorder

OBJECTIVES: Gastric point-of-care ultrasound (POCUS) is a useful tool to identify a high-risk volume of liquid or solid food in the stomach, which increases the risk of perioperative pulmonary aspiration, a rare but highly morbid and potentially fatal consequence of anesthesia care. Risk factors for delayed gastric emptying include not only diabetes, but also many medications such as opioids. We sought to use gastric POCUS to assess for delayed gastric emptying in patients taking methadone, who are part of an understudied patient population. METHODS: We conducted a cross-sectional observational cohort study of adult inpatients receiving methadone for opiate use disorder. Stomachs of hospitalized inpatients taking methadone were scanned using POCUS after an overnight fast, and gastric antral contents were assessed and measured using standardized methods. Patient characteristics were compared using the nonparametric Wilcoxon test and Fisher's exact test. RESULTS: Using gastric POCUS, we found that 11 of 19 patients (57.9%) had "high risk" stomachs by a simulated perioperative assessment, despite an overnight fast. Patients in this cohort with longer fasting periods were more likely to have a "low risk" stomach (p < .05). CONCLUSIONS: Patients on methadone are at higher risk for delayed gastric emptying and may not be safe from a preoperative risk standpoint even after overnight fasting. This is a concerning finding for an already vulnerable population and supports an urgent need to use gastric POCUS to risk-stratify patients at risk for delayed gastric emptying in order to optimize their preoperative safety assessment.