Impairment of proximal renal tubules after pulmonary resection

Abstract

Renal function was tested in 29 patients after pulmonary resection. During the first postoperative week the urine was examined for β₂-microglobulins (u-BMG), which increase with proximal renal tubular dysfunction, and for N-acetyl-β-D-glucosaminidases (u-NAG), which increase when these tubule injury.
In all 29, u-BMG was an abnormally high throughout the week with a peak on the 2nd POD. On the 6-8th POD u-BMG decreased to approximately half the peak level. The u-NAG increased to an abnormal level after the 4th POD, but the increase was slight-only twice the upper limit of normal.
In the high stress group (intraoperative bleeding volume≥1, 000), the u-BMG was still at peak level on the 6-8th POD and the u-N AG level on the 6-8th POD was 5 times the upper limit of normal. Especially in cases with postoperative complications, the levels of both u-BMG and u-NAG increased further on the 6-8th POD.
These results indicate that in cases of pulmonary resection, functional and organic impairment of proximal renal tubules is generally not great. However, with high stress or postoperative complications impairment can be severe and long lasting. Therefore, in these patients, in addition to conventional tests, urinary BMG and NAG should be monitored carefully.