Some degree of fasting is recommended to allow for gastric emptying prior to surgery. This is intended to reduce aspiration of regurgitated gastric contents, with subsequent aspiration pneumonitis.

NOTE: This assumes that the patient has normal gastric emptying. If the patient has delayed gastric emptying then either a nasogastric tube or prolonged NPO (nothing by mouth) may be required. In the event of emergency surgery additional steps may be required to protect the airway.


Age of the Patient

Solids and Nonclear Liquids (Milk, etc.)

Clear Liquids

< 6 months of age

4 – 6 hours

2 hours

6 – 36 months

6 hours

2 – 3 hours

3 – 17 years

6 – 8 hours

2 – 3 hours

>= 18 years (adult)

6 – 8 hours (see below)

2 – 3 hours



• Nonclear liquids include milk and infant formula. The presence of high fat content may delay gastric emptying.


Classically a patient was made NPO (?nil per orum) from midnight. This is fine for early morning surgeries but can be burdensome if the surgery is later in the day.


The times for solids are for light meals. A heavy meal may require a longer fasting period depending on the type and quantity of food.

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