NPO status
Pronunciation: N-P-O
Also written as: NPO — Nil Per Os
The requirement that a patient abstain from oral intake of food and fluids for a specified period before receiving anesthesia or sedation, to reduce the risk of pulmonary aspiration.
Full Definition
NPO (from the Latin nil per os, meaning 'nothing by mouth') guidelines in dental anesthesiology specify minimum fasting intervals for solids, non-clear liquids, and clear fluids before elective sedation or general anesthesia. The American Society of Anesthesiologists fasting guidelines are the standard reference for these intervals. Editors should note that 'NPO' is written in capital letters as an abbreviation, and should be expanded on first use as 'nil per os (NPO)' in formal clinical documents. The status is commonly documented on the pre-anesthetic evaluation form and the procedure consent. 'NPO after midnight' is a colloquial expression that may require replacement with precise fasting interval language in formal manuscripts.
Usage
Usage note: Always write as 'NPO' (all capitals). Expand on first use in formal documents. Avoid the colloquial 'NPO after midnight' in clinical manuscripts; replace with specific fasting intervals per ASA guidelines.
In Context
- "Parents were instructed to maintain NPO status for the child—no solid foods within 8 hours and no clear fluids within 2 hours of the procedure." — Pediatric dental sedation pre-operative instruction sheet
- "The anesthesiologist documented that NPO status had not been observed, resulting in postponement of the elective extraction." — Anesthesia cancellation and reschedule record