SUBJECT:†††† Preoperative Fasting Policy Prior to Elective Procedures


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ORIGINAL ISSUE††††††††† 11.2003

REVIEW††††††††††††††††††††††† 11.2003



Fasting prior to elective procedures requiring anesthesia is intended to reduce the severity of complications related to pulmonary aspiration of gastric contents, should it occur. However, prolonged periods of fasting may lead to dehydration or hypoglycemia and reduces patient satisfaction. In 1999, the American Society of Anesthesiologistsí Task Force on Preoperative Fasting published practice guidelines for preoperative fasting for healthy patients undergoing elective surgical procedures1.These guidelines have also been endorsed by the Canadian Anesthesiologistsí Society are published in their Guidelines to the Practice of Anesthesia2.


Fasting policies should vary to take into account age and pre-existing medical conditions, and should apply to all forms of anesthesia, including monitored anesthesia care. Emergent or urgent procedures should be undertaken after considering the risk of delaying surgery versus the risk of aspiration of gastric contents. The type and amount of food ingested should be considered in determining the duration of fasting. Prior to elective procedures, the minimum duration of fasting should be:

Ingested Material

Minimum Fasting Period


1. Clear Fluids

2 hours

Examples include water, fruit juices without pulp, clear tea, black coffee, carbonated beverages (no alcohol). The volume is less important than the type of liquid.

2. Breast Milk

4 hours

3. Infant Formula

6 hours

4. Light Meal

6 hours

Typically toast and clear fluids.

5. Other Solid Food

8 hours

Meals that include fried or fatty foods or meat may prolong gastric emptying time.




1.      Warner M.A. et al. Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures. Anesthesiology 1999;90:896-905.

2.      CAS Guidelines to the Practice of Anesthesia 2002.