Submitted to: Journal of Pediatric Surgery
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2001
Publication Date: 3/1/2002
Citation: GARZA,J.J., SHEW,S.B., KESHEN,T.H., DZAKOVIC,A., JAHOOR,F. ., JAKSIC,T., ENERGY EXPENDITURE IN ILL PREMATURE NEONATES, JOURNAL OF PEDIATRIC SURGERY, 2002. v. 37(3). p. 289-293. Interpretive Summary: When an adult person is injured or undergoes an operation, his/her need for energy becomes much greater. Although this is not a problem for a well-nourished adult, it can become a problem for very small premature babies undergoing an operation because they have very little energy stored in their bodies and they also need a lot of energy to grow. The problem is that no one knows how much extra energy these premature babies really need after an operation because there is no easy method available to make such a measurement. We developed such a method that involved giving the baby labeled bicarbonate and analyzing its expired air. Using this method we found that the energy needs of premature babies do not increase after they have undergone an operation called "patent ductus ligation". Therefore they should not need extra energy after such an operation.
Technical Abstract: BACKGROUND/PURPOSE: The energy needs of critically ill premature neonates undergoing surgery remain to be defined. Results of studies in adults would suggest that these neonates should have markedly increased energy expenditures. To test this hypothesis, a recently validated stable isotopic technique was used to measure accurately the resting energy expenditure (REE) of critically ill premature neonates before and after patent ductus arteriosus (PDA) ligation. METHODS: Six ventilated, fully total parenteral nutrition (TPN)-fed, premature neonates (24.5 plus minus 0.5 weeks' gestational age) were studied at day of life 7.5 plus minus 0.7, immediately before and 16 plus minus 3.7 hours after standard PDA ligation. REE was measured with a primed continuous infusion of NaH(13)CO(3), and breath samples were analyzed by isotope ratio mass spectroscopy. Serum CRP and cortisol concentrations also were obtained. Statistical analyses were made by paired sample t tests and linear regression. RESULTS: The resting energy expenditures pre- and post-PDA ligation were 37.2 plus minus 9.6 and 34.8 plus minus 10.1 kcal/kg/d (not significant, P =.61). Only preoperative energy expenditure significantly (P <.01) predicted postoperative energy expenditure (R(2) = 88.0%). Pre- and postoperative determinations of CRP were 2.1 plus minus 1.5 and 7.1 plus minus 4.2 mg/dL (not significant, P =.34), and cortisol levels were 14.1 plus minus 2.3 and 14.9 plus minus 2.1 microgram/dL (not significant, P =.52). CONCLUSIONS: Thus, critically ill premature neonates do not have elevated REE, and, further, there is no increase in REE evident the first day after surgery. This suggests that routine allotments of excess calories are not necessary either pre-or postoperatively in critically ill premature neonates. Given the high interindividual variability in REE, actual measurement is prudent if protracted nutritional support is required.