Interventions Aimed at Reducing Fasting Times in Acute Hospital Patients: A Systematic Literature Review

Despite current guidelines recommending fasting from solids for ≤6 hours and clear fluids for ≤2 hours prior to surgery, outdated practices endure; patients fast for unnecessarily prolonged periods because of beliefs regarding aspiration risk upon anaesthesia induction. This literature review aimed to identify and evaluate current interventions aiming to reduce preoperative fasting times for acutely ill hospital patients, summarizing effective interventional strategies and associated outcomes. EMBASE, MEDLINE, PreMEDLINE, and CINAHL were systematically searched. Quality of evidence was assessed using Cochrane risk-of-bias tools. Studies, of any type, reporting fasting times as a primary or secondary outcome were included. A total of 1918 potential studies were identified; of these, 16 studies were included. Seven studies investigated the effect of changing fasting protocol on gastric fluid volume/residual gastric volume (GFV/RGV) and gastric pH as surrogate measures for aspiration risk. No significant differences in GFV/RGV and gastric pH due to reduced preoperative fasting were reported, thus no change in aspiration risk. Eight studies documented improvements in patient-reported outcomes with shorter fasting times. However, this review identified a paucity of studies that trialled interventions to reduce fasting times as the primary aim. These interventions were multimodal and multidisciplinary in nature, incorporating principles of implementation science to successfully achieve significant reductions in fasting times. This review highlights that reducing the preoperative fasting period is safe while improving patient's physical and psychological well-being. Further high-quality studies that investigate multimodal interventions, and that utilize implementation science principles, are required in this area.