Preoperative Gastric Volume Estimation in Diabetic vs Nondiabetic Patients Undergoing Elective Surgeries: A Prospective Observational Study

Background and aims Diabetic autonomic neuropathy can cause gastroparesis and delayed gastric emptying. Hence, it can increase the risk of aspiration during induction of anaesthesia, even after adequate fasting and increase morbidity. This study aims to estimate residual gastric volume using ultrasound in diabetic and nondiabetic patients after a period of fasting and oral fluid intake. Additionally, it seeks to evaluate the impact of long-term blood sugar control on gastric emptying. Methods This prospective observational study included a total of 80 patients, of which 40 were diabetic patients with a history of diabetes for more than five years, 40 were nondiabetic, all were between 35 to 70 years, American Society of Anesthesiologists (ASA) physical status of I-III, scheduled for non-GI elective surgery under spinal anesthesia. Gastric ultrasound was performed after 8 hours of fasting, and then 2 hours after the intake of 200 ml of plain water orally. Craniocaudal (CC) and anteroposterior (AP) were measured, and the antral cross-sectional area (CSA) and gastric volume were calculated. Additionally, the study assessed the impact of diabetes duration, HbA1C levels, and random blood sugar (RBS) on gastric emptying in the diabetic group. For continuously distributed data independent sample t-test was used, and for non-normally distributed data, the Wilcoxon Test/Kruskal-Wallis test was used for the comparisons. Chi-squared test was used for group comparisons for categorical data. Statistical significance was kept at p < 0.05. Results The calculated CSA and GV in diabetics after 8 hours of fasting were 6.91 ± 1.98 cm2 and 55.61± 25.65 ml, respectively, which were significantly higher than in non-diabetics, 4.33 ± 0.96 cm2 and 20.43 ± 10.37 ml (p < 0.001). Similarly, the calculated CSA and GV in diabetics after 2 hours of fluid intake were 7.50 ± 2.07 cm2 and 64.30 ± 27.10 ml, respectively, which were significantly higher than in non-diabetics, 4.61 ± 1.01 cm2 and 24.46 ± 11.28 ml (p < 0.001). Additionally, a strong positive correlation was found between HbA1c (%) and fasting gastric volume (p < 0.001), with gastric volume increasing by 16.12 mL for each 1% increase in HbA1c. Similarly, duration of diabetes and Random blood sugar levels also showed a strong positive correlation with gastric volume, with an increase of 6.21 mL per year of diabetes and an increase of 0.66 mL per 1 mg/dL increase in RBS, respectively. Conclusion Patients with prolonged duration of diabetes and poor glycemic control have higher residual gastric volume; hence, USG-guided assessment can help to take preventive measures for aspiration preoperatively.