Preoperative fasting guidelines

Preoperative fasting has long been a cornerstone of perioperative care, primarily aimed at minimising the risk of pulmonary aspiration during anaesthesia. The historical ‘nil per os from midnight’ policy, once universally adopted, has undergone considerable re-evaluation in recent decades. Growing evidence supporting the safety of shorter fasting intervals, particularly for clear liquids, have led to the revision of fasting guidelines worldwide. Despite these updated recommendations, prolonged preoperative fasting remains common in clinical practice. Contributing factors include outdated protocols, miscommunication, logistical constraints, operating room scheduling, too low priority and variability in guideline implementation. Such practices not only diminish patient comfort but may also lead to metabolic disturbances, with children being especially susceptible. This narrative review explores the rationale, evolution, and current guidelines surrounding preoperative fasting. Both pharmacological and non-pharmacological strategies, such as the use of gastric ultrasound, rapid sequence induction, and gastric tubes, are discussed. The emerging impact of glucagon-like peptide-1 receptor agonists (GLP-1RAs) is also highlighted. By synthesising current evidence, this review aims to provide clinicians with a practical, evidence-based framework for optimising fasting practices and improving perioperative outcomes.