Modernizing perioperative fasting: Liberal clear liquids, glucagon-like peptide-1 receptor agonists, and point-of-care gastric ultrasound

ABSTRACT

Preoperative fasting was historically introduced to reduce pulmonary aspiration during anesthesia; however, contemporary evidence increasingly challenges the assumption that “longer is safer.” Aspiration is a rare event and is primarily determined by patient- and procedure-related risk factors rather than fasting duration alone, whereas prolonged fasting is consistently associated with patient discomfort and adverse physiological consequences. Risk assessment has become more complex with emerging clinical factors, most notably the widespread use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs), which may delay gastric emptying and lead to residual solid gastric contents despite adherence to guideline-recommended fasting intervals. International recommendations for perioperative GLP-1 RA management remain heterogeneous, underscoring the need for pragmatic, risk-stratified strategies that balance aspiration risk mitigation with metabolic stability. Point-of-care gastric ultrasound is increasingly recognized as a valuable bedside decision-support tool, enabling qualitative and quantitative assessment of gastric contents in uncertain or high-risk scenarios and informing airway management and procedural timing. This review synthesizes the current evidence supporting liberal preoperative intake of clear liquids and highlights the transition from rigid, time-based rules toward individualized, physiology-informed approaches to perioperative hydration and nutrition.