Experts say most children fast too long before surgery

A new study presented at the American Society of Anesthesiologists (ASA) 2025 Annual Meeting highlights significant concerns about excessive preoperative fasting times among children undergoing surgery.

Researchers Ethan Lowder, BA, MD student Harvard Medical School, and Alexander Nagrebetsky, MD, MSc, assistant professor at Harvard Medical School, analyzed data from over 71,000 pediatric patients to evaluate fasting durations for clear liquids before surgery. The ASA recommends that children abstain from clear liquids for no more than 2 hours prior to anesthesia. However, the study found that actual fasting periods are far longer than advised.

Across the dataset, the median fasting duration was 10.3 hours, with infants and neonates fasting for a median of 6.4 hours. Additionally, 79% of children were fasted for more than 4 hours—twice the recommended period—and many exceeded 10 hours without clear liquids. These findings underscore a widespread gap between clinical guidelines and real-world practice, potentially exposing children to unnecessary health risks.

Nagrebetsky explained that preoperative fasting has long been used to prevent pulmonary aspiration during anesthesia, yet its true efficacy and safety have not been rigorously studied. Current guidelines are largely based on expert consensus and physiological reasoning rather than strong empirical evidence. While limiting food and liquids before surgery may plausibly reduce aspiration risk, prolonged fasting can cause dehydration, hypoglycemia, irritability, and delayed recovery, especially in young patients. Emerging international evidence, including the EUROFAST study and European guidelines, supports shorter fasting times or even elimination of clear-liquid restrictions in some settings.

The researchers emphasized the need for better implementation of existing guidelines, rather than more restrictive ones. Nagrebetsky recommended institutional “protocolization”—the development of coordinated, interdisciplinary fasting protocols that involve anesthesiologists, surgeons, and nursing staff—to ensure that children can safely consume clear fluids up to 2 hours before anesthesia. Such protocols could reduce unnecessary fasting and its associated harms while maintaining safety standards.

The study’s key takeaway is that excessive fasting before surgery is both widespread and potentially harmful. With nearly 80% of pediatric patients fasting far longer than necessary, the issue represents a public health concern affecting millions of children in the United States. The authors call for additional research to better define safe fasting limits and for hospitals to adopt systematic changes that align clinical practice with evidence-based recommendations.

No relevant disclosures.

Reference

Children fast from clear liquids much longer before surgery than guidelines recommend, large study shows. American Society of Anesthesiologists. October 12, 2025. Accessed October 15, 2025. https://www.eurekalert.org/news-releases/1101055.