• Rationale and Comments

    Fasting after midnight used to be the standard of care before surgery, with thought to reduce pulmonary aspiration risk with an empty stomach. There is adequate data that prolonged fasting is associated with increased perioperative insulin resistance, delayed recovery, and poorer outcomes. Based on this, the American Society of Anesthesiologists and other organizations recommend refraining from solid food for six hours before surgery, while intake of clear fluids is permitted until two hours before surgery.

    Sponsoring Organizations

    • Society of American Gastrointestinal and Endoscopic Surgeons


    • Cochrane Database of Systematic Reviews


    • Surgical


    • McLeod R, Fitzgerald W, Sarr M; Members of the Evidence Based Reviews in Surgery Group. Canadian Association of General Surgeons and American College of Surgeons evidence based reviews in surgery. 14. Preoperative fasting for adults to prevent perioperative complications. Can J Surg. 2005;48(5):409-411.
    • Brady M, Kinn S, Stuart P. Preoperative fasting for adults to prevent perioperative complications. Cochrane Database Syst Rev. 2003;(4):CD004423.
    • Maltby JR, Pytka S, Watson NC, et al. Drinking 300 mL of clear fluid two hours before surgery has no effect on gastric fluid volume and pH in fasting and non-fasting obese patients. Can J Anaesth. 2004;51(2):111-115.