Among the many routine decisions that must be made concerning the preoperative care of pediatric patients, perhaps none is as consistently complicated as the preoperative fasting guidelines. The anesthesiologist must always balance the risks of a full stomach and pulmonary aspiration against the threat of prolonged fasting, dehydration, and hypoglycemia. While making the safest medical decision, the anesthesiologist must also consider the probability of irritable children, disgruntled parents, and a constantly evolving operating room schedule. Large retrospective studies have shown that, although perioperative pulmonary aspiration is more common in children than in adults, it is still rare. Significant morbidity resulting from aspiration is seen even less frequently.

Practices regarding preoperative fasting guidelines vary significantly, as reported in a recent survey of major pediatric hospitals. Most centers agreed on allowing clear fluids for as many as 2 hours and breast milk for as many as 4 hours before a planned procedure. However, there was less concurrence regarding the appropriate fasting period for infant formula and solids. Some institutions restricted intake of formula in a manner similar to solids. Others recommended a fasting period for formula the duration of which was between the durations recommended for clear liquids and solids and was similar to the duration recommended for breast milk. In addition, certain policies dictated fasting intervals based on the patient’s age whereas others placed definitive limits on volumes of ingestible items. These discrepancies, along with frequently unclear policies within individual institutions, have created a great deal of confusion for both parents and health care providers.

In 1999, in an effort to establish clear recommendations regarding nothing by mouth (NPO) status, the American Society of Anesthesiologists (ASA) published Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. These guidelines provide clinical recommendations based on a review of current literature, a large survey of physicians, and a consensus among anesthesiologists within the Task Force on Preoperative Fasting. As part of their recommendations, the task force emphasizes the importance of a preoperative evaluation of each patient and recognition of comorbidities that may increase the risk of pulmonary aspiration. Gastroesophageal reflux, ileus, and bowel obstruction
are prevalent among the pediatric surgical population and certainly warrant individualized preoperative fasting orders based on the severity of the patient’s condition.

The task force’s guidelines are intended for healthy patients who are scheduled for elective procedures and provide appropriate fasting intervals for each type of ingested material. Accordingly, clear liquids may be given as many as 2 hours before a planned procedure. Clear liquids frequently given to pediatric patients include water, ginger ale, popsicles without fruit chunks, fruit juices without pulp, and oral rehydration solutions. For breast milk, the recommended fasting interval is 4 hours. Regarding infant formula, the task force recommends a fasting interval of 6 hours. Similar to that for formula, the recommended fast for solids and milk other than breast milk is 6 hours before the procedure.

For patients requiring preoperative or daily medications, decisions must be made on an individual basis. Pediatric patients generally can safely be given their medications on the morning of surgery with a small amount of water. A prospective study in pediatric surgical patients showed no significant change in gastric pH or residual volume in those given oral midazolam mixed with 5 mL of water. Pediatric anesthesiologists generally accept the risk associated with ingestion of premedications, such as midazolam, just before induction of anesthesia due to the other desirable attributes of these drugs. Special consideration must be given to medications that involve the administration of a larger volume of liquid. The Task Force on Preoperative Fasting does not recommend the routine preoperative use of gastrointestinal stimulants, histamine-2 receptor antagonists, antacids, or antiemetics due to insufficient evidence suggesting a role of these agents in reducing the risk of pulmonary aspiration. The guidelines instead emphasize the importance of the fasting intervals for the specific types of ingested liquids and solids.