TOTAL-BODY WATER IN CHILDREN WITH CONGENITAL HEART-DISEASE, BEFORE AND AFTER CARDIAC-SURGERY

The aim of this study was to measure total body water in children with congenital heart disease before and after cardiac surgery and to compare the results of deuterium and (18)oxygen dilution methods, Seventeen children (aged 4 to 33 months) were given aliquots of isotopically labeled water 1 week before and 6 hours after cardiac surgery, Isotope equilibration and analysis of the declining enrichment of daily urine samples allowed calculation of the total body water content, Before operation, total body water was significantly elevated (p < 0.001, Wilcoxon test); after operation it fell to approximately normal values. This finding is in contrast to those of previous reports, but may be explained in that the method used for calculation depended on measurements taken over a 7-day period rather than on a single measurement of isotope dilution as used elsewhere, Nevertheless, these results do suggest that surgery can correct the preoperative fluid overload, Comparison of deuterium and (18)oxygen dilution methods showed a 2% to 2.5% overestimation of the total body water content with deuterium sampling.