Diabetics have greater residual gastric volume, more prone to aspiration after elective surgery under GA

In general anaesthesia, pulmonary aspiration is the main cause of death and significant morbidity. The incidence of aspiration of stomach content varies from 0.1% to 19%, and aspiration pneumonia accounts for 9% of all anesthesia-related deaths.

The American Society of Anesthesiologists (ASA) fasting guidelines for elective procedures do not account for patients with specific co-morbidities, such as diabetes, and there are no distinct recommendations for emergency surgeries. Likewise, the 2011 recommendations of the European Society of Anaesthesiology (ESA) do not prescribe special fasting protocols for diabetic patients. Therefore, there is presently no clear recommendation for the fasting time to avoid pulmonary aspiration in diabetics. In healthy, fasting individuals with a residual stomach capacity of up to 1.5 ml/kg, the crucial volume threshold for aspiration, there is no appreciable aspiration risk. Point-of-care ultrasonography is a significant technique that may be utilised to measure stomach volume. It is straightforward, easily accessible, noninvasive, and simple to execute. A recently published research compared diabetic and non-diabetic individuals scheduled for elective surgery under general anaesthesia using ultrasound-guided estimation of residual stomach capacity.

This prospective observational research comprised 80 patients split into two groups: 40 diabetic patients with a minimum of 8 years of diabetes history and 40 nondiabetic individuals aged >18 years with American Society of Anesthesiologists physical status I–II and comparable fasting intervals. Before induction of general anaesthesia, standard gastric scanning protocol was used to measure craniocaudal (CC) and anteroposterior (AP) diameters, followed by calculation of antral cross-sectional area (CSA) and gastric volume in semi-sitting (SS) and right lateral decubitus (RLD) position using curved array probe. The stomach antrum volume (GV) was categorised as Grade 0, 1, or 2, and aspiration risk was stratified. After inducing anaesthesia, the nasogastric tube was placed to aspirate and compare the gastric content. In the semi-sitting posture, the mean CC and AP diameters for the non-diabetic group were 16.38 3.31 mm and 10.1 2.53 mm, respectively, compared to 25.19 4.08 mm and 15.8 3.51 mm for the diabetes group. In RLD, the non-diabetic group had a CC of 1.91 0.38 cm and an AP of 1.19 0.34 cm, while the diabetic group had a CC of 2.78 0.4 cm and an AP of 1.81 0.39 cm. Diabetic CSAs of 318.23 97.14 mm2 and 4 1.1 cm2 were considerably greater than non-diabetic CSAs of 133.12 58.56 mm2 and 1.83 0.81 cm2 in SS (p 0.0001) and RLD (p 0.0001) locations, respectively. 15.48 11.18 ml was considerably more in the diabetes group than (-) 9.77 18.56 ml in the non-diabetic group (p 0.0001). Despite disparities in CSA and GV between diabetic and non-diabetic individuals, residual stomach volume was minimal (1.5 ml/kg) in both groups. It was statistically significant (p = 0.0006) that the stomach tube aspirate in the non-diabetic and diabetes groups was 0.30 0.78 ml and 1.24 1.46 ml, respectively.

Anesthesiologists see DM as a significant obstacle in a variety of ways. Due to autonomic gastropathy, diabetic individuals are perceived to have a full stomach and are at an increased risk for pulmonary aspiration. This comparative observational research of 80 patients reveals that long-standing diabetes individuals had a greater residual stomach volume and antral CSA following fasting for elective surgery than non-diabetic patients, as measured by ultrasonography. This indicates that persons with diabetes have delayed stomach emptying. Further research is necessary to stratify fasting volume in diabetes patients in order to develop a preoperative procedure for preventing aspiration in diabetic individuals.

Reference -

Haramgatti A, Sharma S, Kumar A, Jilowa S. Comparison of ultrasound-guided residual gastric volume measurement between diabetic and non-diabetic patients scheduled for elective surgery under general anesthesia. Saudi J Anaesth 2022;16:355-60.