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Evidence summaries

Preoperative Fasting for Adults to Prevent Perioperative Complications

Fluid intake between 1.5 and 3 hours before anaesthesia does not result in an increased risk of aspiration, regurgitation, and related morbidity or increased gastric volume or increased gastric pH compared with the standard 'nil by mouth from midnight' fasting policy. Level of evidence: "A"

A Cochrane review [Abstract] 1 included 22 studies. There were 2 trials (n= 25) allowing fluid intake up to 90 minutes before anaesthesia, and 20 trials (n=762) allowing fluid intake between 120 and 180 minutes before anaesthesia. Few trials reported the incidence of aspiration/regurgitation or related morbidity but relied on indirect measures of patient safety i.e. intra-operative gastric volume and pH. There was no evidence that the volume or pH of participants' gastric contents differed significantly depending on whether the groups were permitted a shortened preoperative fluid fast or continued a standard fast. Participants given a drink of water preoperatively were found to have a significantly lower volume of gastric contents than the groups that followed a standard fasting regimen. Few trials specifically investigated the preoperative fasting regimen for patient populations considered to be at increased risk during anaesthesia of regurgitation/aspiration and related morbidity.

    References

    • Brady M, Kinn S, Stuart P. Preoperative fasting for adults to prevent perioperative complications. Cochrane Database Syst Rev 2003;(4):CD004423. [PubMed]

Primary/Secondary Keywords