Point-of-care ultrasound defines gastric content in elective surgical patients with type 2 diabetes mellitus: a prospective cohort study

BACKGROUND: Delayed gastric emptying and the resultant “full stomach” is the most important risk factor for perioperative pulmonary aspiration. Using point-of-care gastric sonography, we aimed to investigate the prevalence of full stomach and its risk factors in elective surgical patients with type 2 diabetes. METHODS: Type 2 diabetic and non-diabetic elective surgical patients were included from July 2017 to April 2018 in a 1:1 ratio. The study was retrospectively registered at July 2017, after enrollment of the first participant. Gastric ultrasound was performed 2 h after ingesting clear fluid or 6 h after a light meal. Full stomach was defined by the presence of gastric content in both semi-recumbent and right lateral decubitus positions. For patients with full or intermediate stomach, consecutive ultrasound scan was performed until empty stomach was detected. Logistic regression analyses were used to identify risk factors associated with full stomach. RESULTS: Fifty-two type 2 diabetic and fifty non-diabetic patients were analyzed. The prevalence of full stomach was 48.1% (25/52) in diabetic patients, with 44.0% for 2-h fast after clear fluid and 51.9% for 6-h fast after a light meal, significantly higher than 8% (4/50) in non-diabetic patients (P = 0.000). The average time to empty stomach in diabetic patients was 146.50 ± 40.91 mins for clear liquid and 426.50 ± 45.25 mins for light meal, respectively. Further analysis indicated that presence of diabetes-related eye disease was an independent risk factor of full stomach in diabetic patients (OR = 4.83, P = 0.010). CONCLUSIONS: Almost half of type 2 diabetic patients have a full stomach following the current preoperative fasting guideline. Preoperative ultrasound assessment of gastric content in type 2 diabetic patients is suggested, especially for those with diabetes -related eye disease. TRIAL REGISTRATION: The trial was registered at www.clinicaltrials.gov with registration number NCT03217630. Retrospectively registered on 14th July 2017.