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

Abstract 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 diabetes mellitus. Methods Diabetic and non-diabetic elective surgical patients were included from July 2017 to April 2018 in a 1:1 ratio. Gastric ultrasound was performed 2h after ingesting clear fluid or 6h 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 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-hour fast after clear fluid and 51.9% for 6-hour 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 diabetic patients have a full stomach following the current preoperative fasting guideline. Preoperative ultrasound assessment of gastric content in diabetic patients is recommended, especially for those with diabetes mellitus-related eye disease. Key words: diabetes mellitus; gastric emptying; regurgitation and aspiration; ultrasonography