THE INFLUENCE OF SURGERY ON RENAL FUNCTION IN INFANCY AND CHILDHOOD

Abstract

There was no statistical difference in the mean excretion rate of sodium following a test load of hypertonic sodium chloride solution between "control" infants and infants, studied 12 to 24 hours after a variety of surgical procedures. Normal infants between the ages of 1 and 9 months, when given a hypertonic sodium chloride load, excrete sodium at a rate comparable to adults. Two of thirteen infants in the post-surgical period excreted sodium at a rate lower than one standard deviation below the mean for the group. Possible reasons for the lowered excretion rate in these two infants are discussed. Four olden children, given a smaller sodium load than the infants, had a lower excretion rate of sodium pre-surgically. Three of these four children excreted sodium at a lower rate after surgery than they did before surgery. The possible reasons for this are discussed. As measured by glomerular filtration rate, concentration of sodium in the urine, U/P ratio for sodium and the relationship of sodium to water excretion, there does not appear to be an intrinsic defect of renal capacity in handling sodium in the post-surgical state, even in the patients with a lowered sodium excretion rate. From the data collected in this study, there seems to be no reason for altering the generally accepted principles of parenteral fluid therapy in regard to sodium and chloride for the uncomplicated post-surgical patient, following recovery from anesthesia, from that designed for sick children in general.