Extracellular Fluid Deficit Following Operation and Its Correction with Ringerʼs Lactate

Abstract

The changes in extracellular fluid volume (ECV) in two groups of surgical patients, one receiving Ringer's lactate solution intraoperatively and the other receiving only dextrose and water, were assessed. A deficit in the ECV, as measured by radioactive sulfate, of 1.9 +/- 0.8 l (p less than 0.003) compared to the preoperative volume was found in the dextrose group. This was accompanied by a decrease in the mean creatinine clearance (-13% p less than 0.01), the mean urinary sodium excretion (-57% p less than 0.05), and the mean rate of clearance of the sulfate tracer (-18% p less than 0.01). The use of intraoperative Ringer's lactate (1660 cc +/- 96 cc) resulted in no change in the ECV, an increase in the mean creatinine clearance (+10% p less than 0.05), and no change in sodium excretion or tracer clearance. As a result of these findings, it appears that postoperative sodium retention is a physiologic response to a decreased ECV, which can be prevented by the administration of Ringer's lactate.