Where does NPO come from?
The term NPO is a common medical abbreviation for the Latin nil per os, translated as “nothing by mouth.” It is an instruction used when a patient is ordered to not receive food or fluids orally for various medical reasons, especially to prevent what’s called aspiration pneumonia during surgery. Aspiration pneumonia results from foreign material entering into the lung bronchi. During surgery, this occurs when the patient vomits into the oxygen mask. An NPO instruction is intended to keep the stomach empty, and reduce the risk of this occurring.
While the phrase per os (“by the mouth”) appears in the medical texts meaning “administering orally” as early as the 1830s, the full phrase nil per os was being used in medical literature by the 1940s. Evidence of the NPO abbreviation emerges by 1970 in Bruce L. Douglas’s Introduction to Hospital Dentistry.
It’s possible that more frequent usage of the NPO abbreviation began in the 1960s, when American anesthesia textbooks began dictating that patients who are about to undergo surgical procedures the following day should go stop taking food and drinks by mouth after midnight. This was a change from previous, less strict medical directions regarding pre-surgery care. More recently, these recommendations have been revised to tailor NPO lead time to the individual patient by age, medical condition, and urgency of the procedure.
Who uses NPO?
NPO is used by nurses and doctors in medical environments, in order to identify and list patients who should not receive fluid or solids by mouth. Patients are listed as NPO when they are scheduled for surgery, since medical recommendations are for a patient to eat and drink nothing by mouth for a period of time before the operation. This was historically ordered through the phrase NPO at (or past) midnight, but more recently NPO followed by a specified timeframe appropriate for the patient.
An NPO instruction may be called for in other medical cases, such as bowel obstruction, gastrointestinal bleeding, or nasogastric or intestinal tube feeding.
In cases where a patient is likely to resist or forget the NPO order, such as when the patient has dementia, medical professionals will often use the NPO phrase as a noun, or an attribution of the person’s identity. For example, “Don’t give pudding to Tom, he’s an NPO.” This labeling is often viewed negatively by the patient and family of patient.
Patients can also be NPO ahead of a surgery, which they often use in discussion of the difficulty of not eating or drinking for an extended period of time.
NPO is also an unrelated abbreviation for nonprofit organization.
“'You can eat' after a day of npo is the. best. news.”
@live_laugh_kiss Twitter (February 20, 2017)
“You’re about to walk into your patient’s room with a syringe full of insulin. The unit secretary shouts, ‘Hey. The physician just made your patient NPO.’ Ugh...now what?”
Renee Thompson, “To Hold or Not to Hold: Understanding Insulin,” New Nurse Success Shop (September 13, 2013)
“For hospital patients, an NPO order is a condemnation. It translates to wasting away on an intravenous drip while your roommate bitches about the vulcanized chicken on his tray. I have been NPO since the operation.”
Jon Reiner, “The Man Who Couldn't Eat,” Esquire (August 17, 2009)