Evaluation of gastric residual volume in fasting diabetic patients using gastric ultrasound

BACKGROUND: Diabetic patients are claimed to have high risk of delayed gastric emptying; however, the evidence concerning residual gastric volume in fasting diabetic patients is not consistent. The aim of this work is to evaluate residual gastric volume in fasting diabetic patients for elective surgery. METHODS: Fifty patients scheduled for elective surgery under general anaesthesia were included in the study. The study included 25 patients with at least 6-year history of diabetes and 25 healthy controls. Gastric ultrasound was performed to measure antral cross-sectional area in semi-sitting and right lateral positions. Nasogastric tube was inserted after induction of anaesthesia to aspirate and calculate the volume of gastric contents. Both study groups were compared according to antral cross-sectional area, residual gastric volume, risk of aspiration, in addition to demographic data. RESULTS: The diabetic group showed higher median (quartiles) antral cross-sectional area (13.8 [9.5-19.5] mm2 versus 8.8 [5.5-10.5] mm2 , P < 0.001), and higher calculated gastric residual volume, (177 [96-275] mL versus 83 [50-109] mL, P < 0.001) compared to the control group. The diabetic group also showed higher aspirated volume through the nasogastric tube compared to the control group (150 [85-210] mL versus 75 [35-87] mL, P < 0.001). The correlation was very good between calculated residual gastric volume using ultrasound measures and volume of aspirated gastric contents through nasogastric tube. CONCLUSION: Patients with long standing diabetes showed higher residual gastric volume compared to healthy controls after fasting 8 hours for elective surgery.