Pulmonary aspiration of gastric contents is a serious perioperative complication. The Fourth National Audit Project by the Royal College of Anaesthetists has reported pulmonary aspiration as the cause of more than 50% of airway-related deaths in anaesthesia. The resulting respiratory compromise is thought to be related to both volume and nature of the aspirate. The most commonly used measure to prevent aspiration is fasting before anaesthesia, and anaesthesia societies have developed guidelines for preoperative fasting. However, these guidelines apply to healthy patients undergoing elective surgery and not reliable in patients with co-morbidities that affect gastric emptying. 

Gastric emptying is known to be delayed in patients with end-stage renal failure. Though certain biochemical markers have been shown to be associated with delayed gastric emptying in patients with chronic renal failure, there is no acceptable method of identifying such patients before anaesthesia. Gastric ultrasound has recently evolved into a simple, point-of-care tool for evaluating gastric content and volume. The gastric antrum can be easily identified using a low frequency curvilinear probe. By visualising the antrum, not only the contents of the stomach can be determined, but also quantification is possible by application of suitable validated methods. There is paucity of literature with respect to the use of gastric ultrasound to determine residual volume in patients with end-stage renal failure. Hence, the present study is designed to evaluate the gastric contents and volume in patients with end-stage renal failure by gastric ultrasound.