To the Editor:—

I read with interest the report by Brodsky et al.  1regarding pulmonary aspiration of a milk–cream mixture in an adult. I concur with the authors that a delay would have been appropriate, had the anesthesiologist been aware of the recent ingestion of the mixture.

In reference to pediatric practice, the authors cite the recommendation of Litman 2that at least 3 h elapse between breast feeding and surgery. More recently, Ferrari 3reported the results of a survey of hospitals listed in the second edition of the Directory of Pediatric Anesthesia Fellowship Positions.  This survey showed that most of the institutions have a 4-h restriction for breast milk and a 6-h restriction for nonhuman formula before surgery. The same guidelines are reflected in the recently published American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting . 4 

There is evidence that nonhuman milk is cleared more slowly from the stomach than is breast milk. 5,6From the anesthesia perspective, therefore, it would seem prudent to allow at least a 6-h interval before induction of anesthesia in patients who are fed a milk–cream mixture. Because of the high fat content of cream and the compromised nature of patients with a chylothorax, it also would be advisable to perform a rapid-sequence induction in this situation.

The only drawback to waiting 6 h before induction of anesthesia is that the flow of chyle may be past its peak by the time the surgeons expose the thoracic duct. This must be weighed against the risk of pulmonary aspiration, which may, as Brodsky et al.  1reported, be life-threatening.

Brodsky JB, Brock-Utne AJ, Levi DC, Ikonomidis JS, Whyte RI: Pulmonary Aspiration of a Milk/Cream Mixture. A nesthesiology 1999; 91: 1533–4
Litman RS, Wu CL, Quinlivan JK: Gastric volume and pH in infants fed clear liquids and breast milk prior to surgery. Anesth Analg 1994; 79: 482–5
Ferrari LR, Rooney FM, Rockoff MA: Preoperative fasting practices in pediatrics. A nesthesiology 1999; 90: 978–80
American Society of Anesthesiologists Task Force on Preoperative Fasting: 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 nesthesiology 1999; 90: 896–905
American Society of Anesthesiologists Task Force on Preoperative Fasting:
Cavell B: Gastric emptying in infants fed human milk or infant formula. Acta Paediatr Scand 1981; 70: 639–41
Tomomasa T, Hyman PE, Itoh K, Hsu JY, Koizumi T, Itoh Z, Kuroume T: Gastroduodenal motility in neonates: Response to human milk compared with cow’s milk formula. Pediatrics 1987; 80: 434–8