Tolerance to starvation in children on long-term total parenteral nutrition

To evaluate the consequences of long-term cyclic total parenteral nutrition (TPN) on metabolic pathways which contribute to energy metabolism, adaptation to starvation was studied in a group of seven children 2-7 years old, on long-term cyclic TPN. In addition to clinical monitoring, the following biological parameters were measured: blood levels of glucose, free fatty acids, ketone bodies and carnitine, and urinary excretion of dicarboxylic acids. Five of the seven children had good clinical tolerance up to 30 h of fasting. This indicated that metabolic changes arising from prolonged cyclic TPN are easily reversed when such children are fasting. The other two children had to be refed after 22 and 24 h, respectively. Both had metabolic signs of impaired hepatic fatty acid oxidation or ketogenesis. These metabolic changes might reflect the liver failure caused by TPN in these children, and stresses the fact that prolonged starvation has to be carefully monitored in patients with liver dysfunction secondary to TPN.