Residual gastric content after holding of glucagon-like peptide-1 receptor agonists before elective surgery: a cross-sectional study - the RESIDUAL study

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are now increasingly used for glycemic control in type 2 diabetes mellitus as well as for weight loss. Their effect on gastric emptying may increase the risk of aspiration in the perioperative setting; unfortunately, the optimal schedule of perioperative holding of GLP-1 RA is unclear.

We conducted a cross-sectional prospective study at two university affiliated hospitals in Montreal, Canada, comparing the preoperative prevalence of increased residual gastric content (RGC) on gastric ultrasound (GUS) between two groups of fasted adults scheduled for elective surgery: (i) an exposure group of patients receiving a weekly injectable GLP-1 RA and discontinued for ≥ 7 days before surgery, regardless of indication; and (ii) a control group of patients not receiving any GLP-1 RA, preferentially with type 2 diabetes or with a body mass index ≥ 25 kg/m². The primary outcome was increased RGC, defined as the presence of solid content, thick liquid, or > 1.5 mL/kg of clear liquid. Confounding was addressed using overlap-weighting propensity-score adjustment.

93 patients were included. The unadjusted prevalence of increased RGC was 24% (10/41) in the control group and 42% (22/52) in the exposure group. Solid content accounted for 80% (8/10) and 82% (18/22) of positive exams in the control group and the exposure group, respectively. In the unadjusted analysis, there was no statistically significant difference in increased RGC between groups (prevalence ratio, 1.73; 95% CI, 0.96 to 3.75). There was no statistically significant difference between groups after adjustment for confounding (adjusted prevalence ratio, 1.65; 95% CI, 0.7 to 3.7) with an absolute average treatment effect of 15.4% (95% CI, -10 to 35.6).

The prevalence of increased residual gastric content was 42% in patients who had discontinued weekly GLP-1 RA for at least 7 days, compared with 24% in non-exposed controls. Although this difference was not statistically significant, our study was underpowered. The findings therefore represent a clinically relevant but statistically inconclusive signal that the recommended 7-day discontinuation interval may not consistently restore an empty stomach in patients on weekly GLP-1 RA.

This study was registered on clinicaltrials.gov (July 8th, 2024, NCT06500143).