• Posted June 27, 2025

Fasting Might Not Be Necessary Prior To Surgery, Review Concludes

Fasting is a well-known hassle associated with surgery.

Patients are required to go without food or liquid for hours because of fears they’ll vomit while under anesthesia, potentially causing pneumonia if stomach contents are inhaled.

But this long-standing practice might not be necessary, a new evidence review says.

There’s no medical evidence to suggest that fasting reduces the risk of inhaling vomit while sedated, researchers reported June 24 in the journal Surgery.

“At some point, almost everybody will undergo a procedure and there are universal policies in every healthcare facility that require some degree of fasting before surgery,” senior researcher Dr. Edward Livingston, a health sciences professor of surgery at the David Geffen School of Medicine at UCLA, said in a news release.

“Fasting for long periods of time is extremely uncomfortable and patients really don't like to do it,” Livingston added. “Our research suggests that long periods of fasting may not be necessary.”

For the study, researchers pooled data from 17 studies conducted between 2016 and 2023, involving nearly 1,800 patients.

Results showed that a patient’s risk of inhaling vomit during surgery was extremely rare, occurring in four of 801 patients who fasted less or not at all versus seven of 990 patients who fasted as required by guidelines.

“Preprocedural fasting is a standard practice that has been in place for decades and is recommended by clinical practice guidelines,” researchers noted in their study. “Yet very few publications refer to original articles describing why the practice began and the evidence supporting it.”

Researchers concluded people are fasting many more hours than necessary, based on an analysis of more than 80 published papers.

They recommend that clinical trials be performed in which fasting durations prior to surgery are reduced, using modern methods like stomach ultrasound to assess people’s risk for vomiting. Those ultrasound results could be used to judge whether a person could be safely sedated.

More information

The University of Texas MD Anderson Cancer Center has more on myths about fasting prior to anesthesia.

SOURCE: UCLA, news release, June 24, 2025