Bolus intravenous infusion of amino acids or lipids does not stimulate gallbladder contraction in neonates on total parenteral nutrition.

BACKGROUND/PURPOSE: Stimulation of gallbladder contraction in patients receiving total parenteral nutrition (TPN) may be beneficial in preventing cholestatic jaundice associated with TPN. Bolus intravenous administration of either amino acids or fat promotes gallbladder contraction in normal adult volunteers after a period of starvation. This phenomenon has not been investigated in patients receiving continuous TPN. The aim of this study was to test the hypothesis that bolus intravenous infusion of amino acids or fat produces gallbladder contraction in neonates receiving TPN.

METHODS

Twenty-eight studies of gallbladder contraction were performed in 18 neonates receiving continuous TPN (median weight, 2.3 kg; range, 1.3 to 7.3; gestational age, 37 weeks; range, 28 to 40; age, 6.5 days; range, 2 to 180). Different types of experiments were performed: (1) bolus intravenous infusion of amino acid or fat for 60 minutes at twice the normal infusion rate; (2) bolus intravenous infusion of amino acid or fat for 15 minutes at four times the normal infusion rate. Gallbladder volume was measured by real-time ultrasonography by a single investigator. Measurements were made before starting the bolus infusion and every 15 minutes for 1 hour.

RESULTS

The volume of the gallbladder before bolus intravenous infusion was not significantly different between experiments (median, 985; range, 603 to 1,802 mm3). These volumes are consistent with an enlarged and atonic gallbladder as previously reported in infants receiving parenteral nutrition. In all experiments there was no significant decrease in gallbladder volume after bolus infusion of either amino acids or fat.

CONCLUSIONS

Contrary to their effects in adults, bolus infusions of amino acids or fat did not induce gallbladder contraction in neonates on TPN. This may have been because of lack of starvation in the neonates and/or the effect of continuous glucose infusion.