Less Restrictive Pre-Surgical Fasting Guidelines Supported by Study

Changes to fasting policies prior to surgery could impact the length at which patients need to fast, as well as improve patient well-being.

Liberal fasting policies allowing patients to drink clear fluids up until the time of the procedure cut the duration of fasting by an estimated 3:07 hours (interquartile range [IQR] 1:36-7:22), down to a median of 1:20 hours (IQR 0:48-2:24), reported Marije Marsman, MD, of the University Medical Center Utrecht in The Netherlands.

Patients who participated in the new policy also reported decreased thirst (from 46% to 37%), decreased postoperative nausea and vomiting (PONV, from 10.6% to 9.4%), and a decrease in antiemetic administration during recovery (from 11% to 9.5%), potentially improving patient experience (P<0.001 for all), according to the study published in JAMA Surgery.

However, incidence of aspiration increased from 1.7 (95% CI 0.6-2.7) to 2.4 (95% CI 0.5-4.7) per 10,000 cases during the implementation, as did regurgitation, which increased from 18 (95% CI 14-21) to 24 (95% CI 17-32) per 10,000.

"Although a slightly higher incidence of regurgitation could not be ruled out," wrote Marsman and colleagues, "wider implementation of such a policy may be advocated, as results are still within the clinically accepted risks margins. Results suggest that surgical procedures in patients who drink clear fluids within 2 hours before anticipated anesthesia should not be postponed or canceled."

Standard fasting guidelines used in the study recommended that adults abstain from solids for 6 hours and from clear fluids 2 hours prior to receiving anesthesia. Patients could also receive 1 g of acetaminophen with a sip of water anywhere from an hour to 15 minutes before anesthesia.

The more liberal fasting policy allowed for consumption of clear fluids until patients entered the operating room, with no more than a glass of fluid consumed per hour. Acetaminophen was also permitted to be taken with a glass of fluid. No solids were allowed for 6 hours prior to the procedure.

Patients who were not permitted to take anything by mouth prior to surgery or a proven history of aspiration or gastroparesis were not put on the liberal guidelines.

Some prior studies have shown that the execution of fasting guidelines across hospitals is not always ideal, with some patients abstaining from clear liquids 5 to 6 hours before the procedure.

"Inadequate implementation is, among other things, caused by fear of aspiration, anxiety, and loose flexibility in operating room scheduling," wrote Marsman and coauthors. "Although aspiration can lead to aspiration pneumonia and even death, its reported incidences are between 1 and 10 in 10,000 elective procedures."

The group also cited previous research indicating support of more liberal fasting policies, which led to the relaxation of some guidelines for pediatric patients in Europe.

Marsman's group assessed implementation of the quality improvement program for fasting policy progressively rolled out across four different locations in their medical center in order of easiest to hardest to implement. The first location got the liberal policy in June 2019, with other locations joining in November 2019, June 2020, and September 2020. By September 2020, the policy was fully implemented among all patients across the different locations.

A total of 76,451 patients were included in the study, with 22% (16,815) following the liberal policy and 78% (59,036) following the standard policy for comparison.

Data were taken from medical records, including thirst and level of fluid intake. Aspiration, aspiration pneumonia, regurgitation, PONV, and administration of antiemetics were also measured. Duration of fasting was measured from the last patient fluid intake of either 75 mL or half-glass of water prior to receiving anesthesia.

Incidence of regurgitation was 24 per 10,000 patients (95% CI 17-32) with the liberal policy and 18 per 10,000 (95% CI 14-21) in the standard policy group. Regurgitation was more likely among patients who were obese or undergoing surgery for endoscopy. Most regurgitation occurred during anesthesia maintenance.

Among the group who regurgitated (n=146), aspiration was unclear for the majority (75%), while 9.6% were proven to have aspirated and 15% didn't aspirate. Among 14 patients who did aspirate, five (36%) developed aspiration pneumonia and two were ultimately categorized as aspiration pneumonia although the diagnosis was unclear.

Three of the seven patients who developed aspiration pneumonia were part of the liberal policy group and four were from the standard policy group. Aspiration pneumonia incidence among patients using the liberal policy was determined to be 1.8 (95% CI 0.23-3.8) for every 10,000 individuals and 0.7 (95% CI 0.01-1.3) for every 10,000 in the standard group.

Ultimately, aspiration pneumonia led four patients to have an increased hospital stay, and may have contributed to the death of two patients.

Incidence of aspiration was more common with the liberal policy, at 2.5 (95% CI 0.5-4.7) per 10,000 patients versus 1.7 (95% CI 0.6-2.7) for every 10,000 in the standard policy group.

Among 27,284 patients in whom thirst was measured, thirst prior to the procedure was reported by 37% of the liberal policy patients and 50% of the standard guideline patients. In the liberal policy group, 71% (10,010) drank one or more glasses of a clear fluid prior to their procedure.

Limitations to the study included an inability to eliminate residual confounding, due to the study design, or to confidently conclude safety of the approach in terms of aspiration and regurgitation, which would require further study.

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