Gastric Volume and pH in Infants Fed Clear Liquids and Breast Milk Prior to Surgery

Recommendations for fasting intervals prior to anesthesia in pediatric patients have changed in recent years. There are few data concerning infants less than 1 yr of age fed clear liquids or breast milk before surgery. We performed a prospective, blinded study to determine residual gastric volumes and pH in this population. Approximately 2 h prior to surgery, 46 formula-fed infants ingested up to 8 oz of clear liquids and 24 breast-fed infants nursed as usual. After induction of general anesthesia and tracheal intubation, gastric fluid samples were aspirated by a blinded researcher who measured gastric volume and pH. Sufficient gastric fluid for analysis was obtained from 10 (22%) of the infants fed clear liquids and 8 (33%) of the breast-fed infants. For the group fed clear liquids, the residual gastric volume was 0.3 ± 0.9 mL/kg and the pH was 2.1 ± 1.4. Eight (17%) had gastric volumes ≤ 0.4 mL/kg, 2 (4%) had gastric volumes ≤ 1 mL/kg, and 9 (90%) of 10 measured had pH ≥ 2.5. In the breastfed group the residual gastric volume was 0.71 ± 1.1 mL/kg (P = not significant [NS]) and the pH was 2.6 ± 1 (P = NS). All eight (33%) breast-fed infants had gastric volumes ≤ 0.4 mL/kg (P = NS), seven (29%) had gastric volumes ≤1 mL/kg (P = 0.03), and four (50%) of eight measured had pH ≥ 2.5 (P = NS). We conclude that formula-fed infants under 1 y of age who ingest clear liquids up to 2 h prior to surgery are at no greater risk for pulmonary aspiration of gastric contents than are older children reported in previous studies. Breast feeding 2 h prior to surgery is not recommended.