Gastric Emptying in Adults: An Overview Related to Anaesthesia.

Key Words: GASTROINTESTINAL TRACT: stomach emptyingGastric emptying should be considered by anaesthetists not only because of the risk of pulmonary aspiration, but also to determine the systemic availability of substances given orally.Delayed gastric emptying prevents a return to oral feeding, increases nausea and vomiting and may result in morbidity and mortality!The importance of these considerations has increased with recent emphasis on day surgery and shorter admissions.Several papers and editorials have recently re-examined the guidelines for preanaesthetic food and fluid restrictions.2 • 3 This review describes the physiology of gastric emptying, the methods currently in use for its measurement and the limitations of each method.This information may explain many of the apparent contradictions in published data on gastric emptying in the perianaesthetic period.Factors such as disease states and pharmacological effects which may influence gastric emptying are summarised.Unfortunately, few measurements of gastric emptying have actually been made in patients during the perianaesthetic period, so that data must be extrapolated from studies of healthy volunteers, non-surgical patients or from animal studies.In addition these results may not apply to all types of gastric contents as liquids, digestible solids and indigestible solids empty with different rates and patterns, due to the functional anatomy of the stomach.'Both neural and humoral influences on gastric emptying must be considered.The extrinsic innervation of the stomach is via the vagus and sympathetic nerves, and both contain afferent and efferent fibres.5 The stomach wall also has an extensive intrinsic nervous system, the most important component being the '