Studies on the renal function in infancy during surface-induced deep hypothermia and perfusion rewarming--comparison of cardiopulmonary bypass operation with moderate hypothermia
Lee, M.
Nihon Kyobu Geka Gakkai 28(6): 893
1980
ISSN/ISBN: 0369-4739 PMID: 7410912 Document Number: 165028
The renal function on surface-induced deep hypothermia and perfusion rewarming in 36 infants (DH group) and cardiopulmonary bypass operations with moderate hypothermia in 123 cases (1-3 yr: 37, 4-10 yr: 65 and adult:21, CPB group) were studied. In the DH group, average urinary volume (AUV) showed 2.1 ml/kg/h during surface cooling and 1.5 ml/kg/h during rewarming. Anuria was observed in 12 cases during surface cooling and 22 cases during rewarming. AUV showed 7.6 ml/kg 30 min after rewarming. In the CPB group, AUV showed 1.4-4.7 ml/kg/h during perfusion and 4.6-20.4 ml/kg 30 min after perfusion. AUV in the 2 groups gradually began to decrease and after the second postoperative day to increase but there were no differences in AUV between the DH and CPB group. At the phase of polyuria followed immediately by perfusion, urinary urea concentration and urine K showed the lowest values. Similarly osmotic pressure of urine showed the lowest value at this phase. In the DH group, the osmotic pressure remained significantly lower than 450 mOsm/kg H2O until the third postoperative day; in the CPB group, the osmotic pressure showed the maximum 8-12 h postoperatively. CH2O kept on converging into -0.2 Oml/min from the initiation of surface cooling until the postoperative period in the DH group. In the CPB group, it converged into -0.3 Oml/min in 60-90 min after perfusion. The urinary urea concentration level and urine osmotic pressure were highly significant. This suggested that the transition on renal function could be found by measuring the osmotic pressure and the urinary volume. There was little change in the serum and urine Na concentration levels in the 4 groups. In the DH group, the urine Na began to decrease 8 h postoperatively and attention should be directed toward the H2O-electrolyte balance. Hypokalemia during surface cooling was associated with the K ion shifting into other tissues. Supraventricular extrasystole occurred in 6 of 36 cases during surface cooling and disappeared after KCL infusion. These arrythmia were considered to be accompanied by the deletion of K, hypoxia of myocardium and increased myocardial irritability with hypothermia. According to the histological changes after circulatory arrest, slight atrophied glomerules and swelled tubes were observed but these changes were not so remarkable after rewarming.