[Early postoperative changes in pulmonary and renal functions with special reference to postoperative hypoxia in patients with esophageal cancer].

In 89 patients with esophageal cancer, postoperative pulmonary and renal functions, circulatory status and renin-angiotensin-aldosterone system were studied to elucidate the mechanism for renal dysfunction to effect on hypoxia. Renal function fell on early postoperative day, and the free water clearance (CH2O) on postoperative day 0-1 correlated with the PaO2 on postoperative day 3. The renal dysfunction group (CH2O greater than 0.5ml/min on day 0-1) was composed of 37% of the subjects. The renal dysfunction was atributed to the decreased circulatory volume due to increased nonfunctional sequestered water in the sequestration phase, which resulted in the increased circulatory volume due to the mobilized water in the diuretic phase with unrecovered renal dysfunction. This caused hypoxia through the unequal ventilation perfusion ratio. On the other hand, pulmonary dysfunction (PaO2 less than 50mmHg) was noticed in 43 cases (48%), which had the increased secretion of aldosterone on day 2, and this participated in water and sodium retention to worsen hypoxia, and made vicious circle. These findings suggest that the maintenance of the circulation is necessary for the prevention of the postoperative pulmonary dysfunction preceded by the renal dysfunction.