Assessment of residual gastric volume using point-of-care ultrasonography in adult patients who underwent elective surgery

Integrated Multi-Organ Ultrasound

Integrated multi-organ ultrasound is increasingly used across various medical specialties. It should be performed in conjunction with history, physical examination, and other investigations in the diagnostic process to enhance the detection of conditions in the lung, heart, and abdomen. Multi-organ ultrasound has been shown to improve diagnostic accuracy in a sizeable portion of patients, potentially altering treatment plans. Specifically, it aids in assessing shock, sepsis, dyspnea, delirium, and in the perioperative setting, contributing to a more comprehensive patient assessment process.

Preoperative Ultrasonographic Assessment of the Gastric Antrum in Diabetic Patients Before Elective Surgery: A Prospective Observational Comparative Cohort Study

BACKGROUND

Diabetic patients may have neuropathy-induced gastroparesis predisposing them to aspiration. Point-of-care gastric ultrasonography (GUSG) is useful in the qualitative assessment of the antrum and quantitative prediction of gastric volume (GV) in diabetic patients. In this study, we compared the GUSG findings between fasting diabetic and non-diabetic patients in the elective preoperative setting.

METHODS

A total of 220 patients were included in the study with 110 diabetic patients in the diabetes mellitus (DM) group and 110 non-diabetic patients in the non-diabetes mellitus (NDM) group. GUSG was performed in supine and right lateral decubitus (RLD) positions and qualitative grading was done. An empty antrum in both supine and RLD positions was graded 0. Fluid present in the RLD position but empty in the supine position was graded 1. The presence of solids or fluid in both supine and RLD positions was graded 2. Quantitative assessment was done by calculating the estimated GV using the measured cross-sectional area (CSA). The presence of grade 2 antrum or solids or GV >0.8 mL/kg was considered as criteria for a 'high-risk' antrum.

RESULTS

Grade 2 antrum was found in 18% of patients in the diabetic group compared to 3% in the non-diabetic group. Mean CSA (5.65 cm2) and mean GV (34.52 mL) were significantly higher in diabetic patients. Forty-one (37.2%) patients among the diabetic patients had a high-risk antrum and a potentially higher risk of aspiration when compared to non-diabetic patients. Higher age and female gender were found to be associated with the incidence of 'high-risk' antrum in the univariate logistic regression model.

CONCLUSION

Diabetic patients have a higher incidence of grade 2 antrum, and higher CSA and GV, when compared to non-diabetic patients. Risk factors such as female gender and increasing age are associated with the high-risk antrum incidence. Further studies where objective tests are done to identify the presence of diabetic autonomic neuropathy might help determine the relationship between GUSG and aspiration risk.

Preoperative fasting and the risk of pulmonary aspiration-a narrative review of historical concepts, physiological effects, and new perspectives

In the early days of anaesthesia, the fasting period for liquids was kept short. By the mid-20th century 'nil by mouth after midnight' had become routine as the principles of the management of 'full stomach' emergencies were extended to include elective healthy patients. Back then, no distinction was made between the withholding of liquids and solids. Towards the end of the last century, recommendations of professional anaesthesiology bodies began to reduce the fasting time of clear liquids to 2 h. This reduction in fasting time was based on the understanding that gastric emptying of clear liquids is rapid, exponential, and proportional to the current filling state of the stomach. Furthermore, there was no evidence of a link between drinking clear liquids and the risk of aspiration. Indeed, most instances of aspiration are caused by failure to identify aspiration risk factors and adjust the anaesthetic technique accordingly. In contrast, long periods of liquid withdrawal cause discomfort and may also lead to serious postoperative complications. Despite this, more than two decades after the introduction of the 2 h limit, patients still fast for a median of up to 12 h before anaesthesia, mainly because of organisational issues. Therefore, some hospitals have decided to allow patients to drink clear liquids within 2 h of induction of anaesthesia. Well-designed clinical trials should investigate whether these concepts are safe in patients scheduled for anaesthesia or procedural sedation, focusing on both aspiration risk and complications of prolonged fasting.

Preoperative ultrasound assessment of gastric content in patients with diabetes: A meta-analysis based on a systematic review of the current literature

STUDY OBJECTIVE

To conduct a systematic literature review of the current evidence on the effect of diabetes mellitus on gastric volume observed during a preoperative ultrasound examination. Using the results of this systematic literature review, a meta-analysis was performed to investigate whether there was an association between diabetes mellitus and an increased risk of presenting with a high-risk stomach (gastric volume associated with an increased risk of pulmonary aspiration).

DESIGN

Review article and meta-analysis.

SETTING

Review of published literature.

PATIENTS

A total of 3366 patients underwent surgery.

INTERVENTION

Gastric ultrasound examination.

MEASUREMENTS

Data for the meta-analysis and literature review were collected from the PubMed/Medline, Embase, Web of Science, and Google Scholar databases of the National Library of Medicine from the date of inception to January 2023. All included studies measured the gastric antral cross-sectional area and/or gastric residual volume in patients with diabetes and those without diabetes. The data utilized in the meta-analysis included all studies that evaluated the incidence of high-risk stomachs based on ultrasonographic measurements of the gastric antral cross-sectional area or gastric residual volume.

MAIN RESULTS

Most collated studies revealed that diabetes mellitus was associated with increased antral cross-sectional area and gastric residual volume. A meta-analysis of published reports indicated that patients with diabetes have an increased rate of high-risk stomachs.

CONCLUSIONS

Diabetes mellitus is associated with an increased rate of high-risk stomachs. The authors recommend large prospective trials to ascertain the safety of the current fasting guidelines for patients with diabetes undergoing surgery.