The Effect of Different Pre-Operative Feeding Regimens on Plasma Glucose and Gastric Volume and pH in Infancy

The effects of four different pre-operative feeding regimens were studied in 123 children below the age of one year presenting for surgery. Plasma glucose concentrations, blood acid-base values, gastric volume and gastric pH were measured before and after induction of anaesthesia. No patient was found to be hypoglycaemic and there were no significant differences in plasma glucose concentration and acid-base values between the groups. No correlation was demonstrated between the age and weight of the patients and the duration of fasting and the plasma glucose concentration. There was a significant elevation of plasma glucose concentration in all four groups after induction of anaesthesia (P<001) compared with the pre-induction level which is a reflection of the stress of blood sampling and induction of anaesthesia. Infants less than three months of age in the milk-feed group had a significantly higher gastric volume with low pH (P< 0.05) signifying a potentially greater risk of pulmonary acid aspiration. The practice of timing the last pre-operative feed in infancy according to the infant's normal feeding pattern does not appear to increase the risk factors for pulmonary aspiration, if milk is avoided.