One surefire way to start a lively conversation among anesthesiologists is to bring up the ideal timeline children should fast before surgery.

This clinical controversy was the focus of a point-counterpoint discussion at ANESTHESIOLOGY® 2024. Joelle Karlik, MD, Pediatric Anesthesia and Pain Medicine, Children’s Healthcare of Atlanta-Arthur M. Blank Hospital, Atlanta, Georgia, makes the case that it’s realistic and safe to shorten the fasting time to one hour for many procedures. This article will be followed by a counterpoint from Jerrold Lerman, MD, on reasons to maintain the two-hour window to withhold clear liquids before elective procedures requiring anesthesia.

“It’s not uncommon for parents to miscalculate the time of the child’s liquid fast and even more frequent to fast longer than recommended out of an abundance of caution.”

The 2023 ASA Practice Guidelines for Preoperative Fasting state that the current recommendations are for pediatric patients to strive for clear liquid intake as close to two hours before procedures as possible (Anesthesiology 2023;138:132-51). However, some professionals believe these guidelines are inconsistent with clinical practice, especially in European or Canadian hospitals, according to Dr. Karlik. “A large amount of the research is coming out of Europe in terms of the safety of this one hour clears policy which, per their arguments, is safe,” she confirmed.

The two-hour clear fasting requirement was developed to account for aspiration risk under NPO instructions. Aspirations are an unavoidable risk in anesthesiology, but the argument has always been that ingesting clear liquids just before surgery increases that risk. Some recent research challenges this logic (Paediatr Anaesth 2023;33:1012-19). Dr. Karlik led a small study in which patients were given liquids based on their weight within an hour before the estimated surgery start time and prior to their anesthetic. Once induced, the team measured the patient’s gastric volume to gauge if it was at a level that caused concern for aspiration. Her team concluded that there was no correlation between longer fasting times and increased aspiration risk. However, they acknowledged the challenge of needing a large study population to conduct a proper trial and the reality that aspirations do occur, even with two-hour NPO orders.

After a literature review, what emerged as the most important consideration was the different nutritional needs for the pediatric versus adult patient populations. Growth and nutrition are greater concerns for infants and children, as they metabolize nutrients at a higher rate than adults. The youngest patients are more sensitive to alterations in their nutrition. More importantly, patients of any age tend to fast longer than recommended. “With prolonged fasting, children have signs of hypoglycemia and acidosis. Their blood pressure is actually lower during induction of anesthesia, and, during surgery, they show signs of insulin resistance, which is associated with increased risk. These patients are already fragile and therefore we need a policy that reflects that,” explained Dr. Karlik.

Another argument in favor of the one-hour fast before elective surgery is that it makes an already stressful experience easier on parents. It’s not uncommon for parents to miscalculate the time of the child’s liquid fast and even more frequent to fast longer than recommended out of an abundance of caution.

“The one-hour NPO policy is easier to follow,” she noted. “We can instruct parents that their child can drink clear liquids until arrival at the hospital. The policy is clear and flexible enough that we can decrease the risk of prolonged fasting, which also has emotional/psychological effects on the child and parents.”

A one-hour policy also reduces the chance of miscommunication, as patients often receive one set of preop instructions from the surgeon and a different set from anesthesiology. Logical preoperative instructions with clear messaging go a long way in improving the patient and family experience, said Dr. Karlik.

Dr. Karlik is quick to note that the one-hour fast rule should only be applied to an otherwise healthy patient population. Additional caution must be heeded for patients with diabetes, many GI disorders, or those who present to the hospital under emergent or trauma circumstances. Using appropriate clinical judgement is key.

As with any new policy, staff education and messaging are critical to its success. “Our perioperative nurses love the one-hour policy,” attested Dr. Karlik, noting that buy-in from the surgeons, preoperative screeners, and preoperative nurse practitioners is another non-negotiable.

“Regardless of your institution’s policy – whether it’s one or two hours – adherence to your guidelines is most important,” she emphasized. “Two hours of not having clear liquids is not dangerous. What is dangerous is prolonged fasting. Even if an institution isn’t interested in a one-hour clear policy, there are still opportunities for interventions and quality improvement to improve pediatric patients’ preoperative status.”