ASA NPO timing

Minimum fasting periods before elective procedures requiring sedation or general anesthesia (ASA Practice Guidelines, 2017 + 2023 updates).

Ingestion	Minimum NPO
Clear liquids (water, black coffee, pulp-free juice, sports drinks)	2 h
Breast milk	4 h
Infant formula	6 h
Non-human milk (cow, soy)	6 h
Light meal (toast + clear liquid)	6 h
Fried/fatty meal or meat	8 h

Update — clear liquids ≤ 2 h

ASA 2023 update reaffirmed the 2-hour rule for clear liquids, and emphasized that patients should be encouraged to drink up until 2 h pre-op (rather than NPO past midnight). Carbohydrate-rich clear drinks 2-4 h pre-op (ERAS protocols) reduce postop nausea + insulin resistance.

Special populations

Pregnancy + active labor: Always considered full stomach regardless of NPO time — RSI for GA, neuraxial preferred.
Diabetes / gastroparesis: Delayed gastric emptying — extend solid food fasting to 8 h, consider POCUS gastric assessment.
Trauma / acute pain: Stress + opioids slow gastric emptying — full stomach precautions even if "NPO since X."
Bowel obstruction / ileus / appendicitis: Full stomach by definition, regardless of fasting.
GLP-1 receptor agonists (Ozempic, Wegovy, etc.): Significantly delay gastric emptying. ASA 2023: hold daily dosing 1 day pre-op; weekly dosing hold 1 week pre-op. POCUS gastric assessment if uncertain.

Education only. Institutional protocols may differ — follow yours. Not a substitute for clinical judgment.