Abstract No.: ABS1363: A comparative evaluation of gastric residual volume using ultrasound in fasting diabetic and non-diabetic adults undergoing elective surgery under general anaesthesia.

BACKGROUND & AIMS: Diabetic patients despite standard preoperative fasting may be at an increased risk of aspiration due to gastroparesis. This study aimed to evaluate the gastric residual volume using ultrasound in fasting diabetic and non-diabetic adults undergoing elective surgery under general anaesthesia. METHODS: This study was conducted in 30 non-diabetic and 30 diabetics, aged 40 to 80 years, of either gender, BMI <35kg/m2, belonging to American Society of Anesthesiologists physical status I-III. Pregnant patients, those with history of upper gastrointestinal morbidity or upper abdominal surgery and patients with liver and kidney disease were excluded. Preoperatively, using gastric sonography, antrum was assessed in semi-setting and right lateral decubitus positions. The type of gastric contents (empty, fluid, solid) was noted, and gastric residual volume (GRV) was estimated by measuring antral cross-sectional area (CSA) and using mathematical models. After induction of anaesthesia, orogastric tube was inserted and gastric contents aspirated. RESULTS: Diabetic patients had significantly higher mean antral CSA and calculated mean GRV in both right lateral and semi-sitting position (p <0.0001). Gastric antrum appeared empty in significantly greater number of non-diabetic patients as compared to diabetic patients in both right lateral (p <0.0001) and semi-sitting positions (p =0.0002). A higher mean volume of gastric aspirate was also found in the diabetics as compared to the non-diabetics (p <0.0001). CONCLUSION: The current fasting guidelines for elective surgery are not conclusive in patients with long-standing diabetes. Hence, we recommend the use of point-of-care ultrasound as an effective screening tool to assess the aspiration risk and to tailor anaesthetic management.