[Fat utilization in newborn infants with and without heparin administration. Comparative study with the 13C-triolein breath test].

The elimination of parenterally administered lipids from the bloodstream of premature infants can be accelerated by activation of the lipoprotein-lipase using heparin. We have no evidence that the free fatty acids increasing under enhanced lipolytical activity are utilized for energy production. For this reason, the oxidation rates of intravenously administered lipids in premature infants are examined both with and without heparin. Triolein marked with 13C and processed in soybean oil is administered intravenously at a dosage of 10 mg/kg. 13CO2 results from fatty acid oxidation and is exhaled through the lungs, whereafter it is collected in separate breath samples over a period of 6 hours and determined by mass spectrometry. The examination was performed in 5 premature infants, first without heparin, then after heparin injection (10 U/kg). The extent of 13CO2 exhalation was not significantly influenced by heparin. Without heparin supply we measured a fatty acid oxidation of 32.0 +/- 2.57% which was the same (31.6 +/- 2.34%) after heparin injection. Single intravenous administration of 10 U heparin/kg does not cause increased fatty acid oxidation in premature infants.