[Effect of respiratory failure on water and sodium metabolism]

Water and sodium loading tests were undertaken in 27 cases of cor pulmonale with acute exacerbation. The results showed that ratio of 2 hour urine volume versus water load was 23- +/- 1.38% in respiratory failure (RF) group (17 cases), which was significantly lower than that of non-RF group (10 cases) 51.3 +/- 4.17%, (P less than 0.01) and control group (7 cases) 57.4 +/- 6.54%, (P less than 0.01); ratio of 4-hour urine sodium versus sodium load was 12.0 +/- 1.48% in RF group, which was also lower than that of non-RF group (29.6 +/- 1.93%, P less than 0.01) and control group (30.4 +/- 2.42%, P less than 0.01). It was suggested that excretions of water and sodium decreased in RF group. The incidences of hyponatremia and hyposmosemia were 47.1% and 64.7% respectively in RF group in 6 cases of RF with edema, the excretions of water and sodium increased after oxygen treatment. The mechanism and the clinical significance of hyponatremia and hyposmosemia and of impaired excretions of water and sodium in RF patients were discussed preliminarily. It is concluded that hypoxemia is one of the important causes of the disturbance in water and sodium metabolism.