Guidelines for Perioperative Fasting

Please note: These are generalized guidelines. Specific details are provided by the anesthesiologist.

In general, most patients can tolerate fasting without discomfort if their surgery is before noon. I usually tell these patients to remain NPO except for essential medications. However, for surgery after 12 noon, they can have clear liquids up to four hours before induction of anesthesia. The ASA guidelines for clear liquids is actually up until two hours before surgery, but four hours leaves less room for error and allows the OR to move up a scheduled case more readily.

For adults having elective surgery:

• No solid food of any kind after midnight, regardless of the scheduled start time.
• Patients may have clear liquids up until four hours before induction of anesthesia. Clear liquids are water, clear juices, black tea, black coffee, carbonated soda and clear broth. Alcoholic beverages are not considered clear liquids.

Minimum fasting period for infants and children having elective surgery:

(child defined as individual age 12 and under)

 

Clear liquids	2 hours
Breast milk	4 hours
Non-human milk (including infant formula)	6 hours
Solids	8 hours

 

This is commonly known as the two, four, six, eight rule in pediatric anesthesia practice.