Preoperative Fasting (NPO):
Guidelines for Breastfed Infants and Children
Prospect CT USA
From: LEAVEN, Vol. 37 No. 6, December 2001-January 2002, pp. 132-133.
Families facing surgery or other medical procedures with their infants and young children confront many challenges. One such issue is preoperative fasting that restricts the intake of all ingested material, including human milk.
When a mother calls La Leche League to request information about preoperative fasting for her nursing child because she has been told her child must not have anything by mouth for several hours before surgery is scheduled, it is easy to empathize with her distress. Helping her to plan alternatives that will comfort and distract her child when nursing is not possible is one way of supporting her. She may need help in understanding the reasons for the fasting period or tips on how to dialogue with her child’s health care providers. During interactions with the health care providers involved in her child’s care and treatment, it is important for her to be her child’s advocate, yet also develop a rapport that is positive and productive with each care provider. Leaders can also be an important resource, offering the mother information regarding the issues related to pre-anesthesia fasting practices.
Preoperative fasting practices are an attempt to minimize the volume of the gastric residual (the fluid left in the stomach), which has traditionally been thought to reduce the chance of pulmonary aspiration (stomach contents getting into lungs). Since pulmonary aspiration of gastric contents is a potentially life-threatening complication of general anesthesia, the concerns of health care providers are understandable. Clinical research generally supports either two or three hours of fasting before anesthesia for fully breastfed infants. Some studies (Cavell 1981; Husband 1969; Litman 1994) have concluded that the rate of gastric emptying of human milk is twice as fast as that for infant formula but not quite as fast as clear liquids. However, the lung damage possible from a potential aspirate is as important a consideration as the gastric emptying time. James (1984) found that a low volume of aspirate with a very low pH (i.e., high acidity) is far worse than a higher volume of aspirate with a higher pH (lower acidity). Lung damage from aspiration of saline solution appears to be less than that of aspirated human milk or infant formula according to one study (O’Hare 1996). These are the concerns that influence preoperative fasting practices and policies.
Despite the risks associated with potential pulmonary aspiration, it is worthwhile to consider the benefits of having as short a fasting time as is safely possible. In addition to the obvious psychological advantages for breastfeeding children having reduced preoperative fasting times, “liberalization of preoperative fluid intake may decrease patient irritability, increase parent satisfaction, reduce the incidence of severe hypotension during anesthetic induction due to hypovolemia, and reduce hypoglycemia” (Ferrari 1999).
According to the BREASTFEEDING ANSWER BOOK (1997 revised edition, page 290), “Although some doctors require that a patient be given nothing by mouth (‘NPO’) for eight hours before surgery, these guidelines are in the process of changing. Recent studies indicate that a more reasonable fasting time before surgery is six hours for formula (Spear 1992), three hours for human milk, and two hours for clear liquids (Litman 1994; Schreiner 1994). The mother should discuss the NPO orders with the surgeon and anesthesiologist beforehand; many are willing to accommodate the needs of the breastfeeding baby.”
An article in BREASTFEEDING ABSTRACTS (Nicholson and Schreiner 1995) examined the issues and data relating to the determination of a safe fasting interval for human milk prior to the induction of anesthesia. The rationale for less restrictive feeding guidelines, with infants allowed to ingest either clear liquids or human milk up to two or three hours prior to induction of anesthesia, is explored. The author also states, “Once sufficient clinical experience has been accumulated for each fasting interval, then it will be possible to determine whether this practice is safe.”
Unfortunately, the scarcity of data on the rate of gastric emptying of human milk in infants, coupled with the fear of pulmonary aspiration of gastric contents, often leads to more conservative NPO guidelines. This is despite the fact that perioperative aspiration (aspiration just before, during, or immediately after surgery) is infrequent in children. A recent study (Ferrari 1999) of pediatric preoperative fasting practices in various institutions around the country determined that human milk ingestion was restricted for four hours before anesthesia for all age groups (both less than six months and more than six months) in most, but not all, institutions.
The Ferrari study also noted that institutions differed in their categorization of human milk. It may be considered the equivalent of a clear liquid, a solid, artificial baby milk, or something in between: 23 percent considered it as a clear liquid, 36 percent as between a clear liquid and formula, 7 percent the same as formula, and 34 percent as a solid. The category chosen affected the length of time that human milk was withheld.
The effect of human milk’s categorization is evident in the most recent consensus practice guidelines issued by the American Society of Anesthesiologists (ASA) (1999) where human milk is treated as being in between clear liquids (with a minimum fasting time of two hours) and non-human milk (with a minimum fasting time of six hours). The minimum fasting time the ASA recommends for human milk is four hours. Although this supports and promotes reduced fasting time in institutions that have or had policies with fasting times greater than four hours, this interval still represents a hardship for breastfeeding families striving to normalize a difficult situation and comfort their child. It is no wonder that caring parents and health care providers continue to question the necessity for this hardship and attempt to reduce the preoperative fasting interval within reasonable safety limits.
Some reputable institutions allow a briefer fasting period than the ASA guidelines for human milk ingestion. The 1994 articles by Litman and Schreiner and referred to in the BREASTFEEDING ANSWER BOOK also support and suggest a three-hour fasting time for human milk. Furthermore, tests, medications, and procedures should be scheduled with consideration for the baby’s nursing needs, for example, scheduling procedures and surgeries early in the morning. Presurgery NPO orders for breastfed babies should reflect the easy digestibility of human milk (exclusively breastfed babies can have nearly empty stomachs in two to four hours) and a baby may be allowed to suck at the breast for comfort on an “emptier” recently pumped breast, according to The Hospitalized Nursing Baby (Popper 1998). Ruth Lawrence, MD, Director of University of Rochester’s Lactation Study Center and a member of LLLI’s Health Advisory Council, states that “Instructions to breastfeeding mothers should limit the amount of breastfeeding after four hours and permit feeding on a prepumped breast predominantly for comfort” (Breastfeeding: A Guide for the Medical Profession, 5th edition, 1999, page 497).
Leaders have many resources available to them as they help mothers. THE WOMANLY ART OF BREASTFEEDING and BREASTFEEDING ANSWER BOOK are full of references. There are many articles from LEAVEN, NEW BEGINNINGS, and BREASTFEEDING ABSTRACTS available through the LLLI Web site: www.lalecheleague.org/ If the Leader needs more information, she can contact her local Professional Liaison (PL) Leader. If the local PL Leader needs more information, she can contact the Division/Affiliate PL Resource Leader, who can contact the Center for Breastfeeding Information if needed.
I salute the parents whose love and concern for their infants and young children inspire them to question recommendations and make informed health care choices. It is their persistence that requires current fasting practices and guidelines to be repeatedly evaluated and supported by up-to-date evidence. One of the rewards of LLL leadership is being a supportive resource for these parents.
- American Society of Anesthesiologist (ASA). Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures - A Report by the American Society of Anesthesiologists Task Force on Preoperative Fasting. Anesthesiology 1999 Mar; 90(3): 896-905.
- Cavell, B. Gastric emptying in infants fed human milk or infant formula. Acta Paediatr Scan 1981; 70(5): 639-4.
- Ferrari, L. R., et al. Preoperative fasting practices in pediatrics. Anesthesiology 1999; 90(4): 978-80.
- Husband, J. and Husband, P. Gastric emptying of water and glucose solutions in the newborn. Lancet 1969; 2(7617): 409-11.
- James, C. F., et al. Pulmonary aspiration—effects of volume and pH in the rat. Anesth Analg 1984 Jul; 63(7): 665-8.
- Lawrence, R. A. Breastfeeding: A Guide for the Medical Profession, Fifth Edition. St. Louis: Mosby, 1999; 497.
- Litman, R. S., Wu, C. L., and Quinlivan, J. K. Gastric volume and pH in infants fed clear liquids and breast milk prior to surgery. Anesth Analg 1994; 79: 482-85.
- Morbacher, N. and Stock, J. Breastfeeding Answer Book, Revised Edition. Schaumburg, Illinois: LLLI, 1997; 290, 293-294.
- Nicholson, S. C. and Schreiner, M. S. Feed the babies. Breastfeeding Abstracts 1995; 15(1): 3-4.
- O’Hare, B. et al. Acute lung injury after instillation of human breast milk or infant formula into rabbits’ lungs. Anesthesiology 1996 Jun; 84(6): 1386-91.
- Riordan J. and Auerbach, K. Breastfeeding and Human Lactation, Second Edition. Sudbury, MA: Jones and Bartlett, 1999; 652.
- Schreiner, M. S. Preoperative and postoperative fasting in children. Ped Clin N Am 1994; 41(1): 111-20.
- Spear, R. Anesthesia for premature and term infants: perioperative implications. J Pediatr 1992; 120(2 pt 1): 165-75.
- Splinter, W. M., et al. Preoperative fasting in children. Anesth Analg 1999; 89: 80-9.
Sue Iwinski lives in Prospect, Connecticut, USA with her husband Greg, and children Justin (14) and Julie Ann (9). Sue’s experience as an LLL Leader and an Assistant Area Professional Liaison Leader enabled her to find her second calling; she is employed part-time as clinical assistant to a physician who specializes in breastfeeding medicine. This article was inspired by a request for information from a Leader on behalf of her baby, Bobby, prior to his cardiac surgery.