To investigate the effects of fluid restriction on perioperative plasma aldosterone for the aged patients.

Patients with gastrointestinal neoplasms from June to October 2012 were divided into two groups, the aged group(≥65 years old, 40 cases) and the non-aged group(<65 years old, 40cases). They received fluid restriction therapy during perioperative period. To observe plasma aldosterone on the day before operation, the first day, the second day and the third day after operation, and postoperative vital sign, such terms as arterial blood lactic acid, fluid volume and urinary volume per hour in the two groups were recorded.

There were no differences of arterial blood lactic acid, fluid volume and urinary volume per hour in the two groups. The plasma aldosterone was significantly lower in the aged group before operation, t=2.164, P=0.034. The postoperative plasma aldosterone was increased, and reached peak on the second day after operation. The postoperative plasma aldosterone was higher in the aged group, and there was significant difference on the first day after operation, t=-2.300, P=0.024.

Compared to the non-aged group, the plasma aldosterone of the aged group is significantly lower before operation, and higher after operation, especially the first day after operation.