PARADOXICAL POSITIVE NITROGEN-BALANCE IN BURN PATIENTS RECEIVING HIGH-DOSE ADMINISTRATION OF INSULIN FOR NUTRITIONAL CARE

Background. Nitrogen balance in patients who need high-dose administra tion of insulin has not been evaluated clinically. The purpose of this study was to compare the difference in nitrogen balance between burn patients who received high-dose administration of insulin and those wh o did not. Methods. This study was performed in 19 severely burned adu lts with no liver or kidney failure. Patients were divided into two gr oups on the basis of the mean ratio of administered insulin and calori e intake (I/C) for the initial 4 weeks, a high I/C group (n = 9) and a low I/C group (n = 10). There were no significant differences between the two groups regarding age, percentage of area burned, and body wei ght. Nitrogen balance, blood urea nitrogen, and urine urea nitrogen we re measured in all patients. Plasma concentrations of glucose, insulin , glucagon, cortisol, and urinary excretion of 3-methyl-histidine were measured in 12 patients (six in each group). Results. Until day 10 bo th groups exhibited similar changes in plasma concentrations of glucos e, insulin, glucagon, and cortisol. Subsequently, plasma concentration s of insulin and glucagon began to decrease in the low I/C group, wher eas a high level was sustained in the high I/C group (p < 0.05). Plasm a glucose and cortisol measurements showed no significant differences between the two groups. Blood urea nitrogen levels and urinary excreti on of 3-methyl-histidine were not different between the two groups. Ur ine urea nitrogen excretion in the high I/C group, however, was signif icantly lower than that in the low I/C group from day 8 (p < 0.05). Th us the high I/C group achieved positive nitrogen balance more quickly than the low I/C group. Paradoxically, however, the high I/C group was at higher risk of septic complications and exhibited higher mortality than the low I/C group (p < 0.05). Conclusions. These results indicat e that an improvement in nitrogen balance, which is accepted as a good thing in the management of critically ill patients, is not necessaril y good in the high I/C group and that residual nitrogen was retained w ithin the body in the high I/C group.