Fasting Guidelines 

 

Adapted from American Society of Anesthesia 2011 Fasting Guideline & 2017 CAS Guidelines to practice of anesthesia   Full guidelines here: 

 

 

 

 

 

 

Preoperative Fasting Status 

 

• Adults: 

  • Clear Fluids: 2 hrs 

  • Light meal & Non-human mild: 6 hrs 

  • Fried fatty meal/meat: 8 hrs 

• Pediatrics:  

  • Breast milk: 4 hrs 

  • Formula: 6 hrs 

 

 

Pharmacologic Therapy 

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• Gastrointestinal Stimulants 

  • DO NOT USE ROUTINELY if average risk of reflux/aspiration 

  • Maxeran

    • good evidence for gastric emptying 

    • no good evidence for reducing acidity 

• Gastric Acid Reducing Agents 

  • DO NOT USE ROUTINELY if average risk of reflux/aspiration 

  • All H2 receptor antagonists (cimetidine, ranitidine, famotidine) effective for reducing gastric volume & acidity.  Miller says Ranitidine most effective for reducing the gastric volume. 

  • PPI effective for reducing gastric volume & acidity 

  • Insufficient evidence to decide between H2-blocker VS PPI 

• Antiemetics

  • DO NOT reduce the risk of aspiration in otherwise normal patients

  • Should NOT be routinely used

  • Effective only for PONV 

• Anticholinergics

  • NOT recommended routinely 

  • Equivocal evidence that they reduce gastric volume or acidity