Changes in the plasma sodium concentration after minor, moderate and major surgery
Article first published online: 8 DEC 2005
Copyright © 1987 British Journal of Surgery Society Ltd.
British Journal of Surgery
Volume 74, Issue 11, pages 1027–1030, November 1987
How to Cite
Guy, A. J., Michaels, J. A. and Flear, C. T. G. (1987), Changes in the plasma sodium concentration after minor, moderate and major surgery. Br J Surg, 74: 1027–1030. doi: 10.1002/bjs.1800741123
- Issue published online: 8 DEC 2005
- Article first published online: 8 DEC 2005
- Manuscript Accepted: 17 MAY 1987
The plasma sodium concentration, [Na]P, falls following major surgery and this fall is exacerbated by the administration of sodium-free or sodium-low intravenous fluids in the postoperative period. As a prelude to prospective, but controlled, studies we observed the range of [Na]P on admission for surgery in 477 patients. In 309 patients the extent of the change in [Na]P by the first postoperative day (Δ[Na]) was related to the severity of the operation undergone (minor, moderate or major) and the volume of potentially hypo-osmolar intravenous fluid given. The mean admission [Na]P was significantly lower with increasing severity of proposed operation. A highly significant fall occurred in [Na]P following surgery of every grade; such falls in [Na]P were seen even when no potentially hypo-osmolar fluids were administered. A significant inverse relationship between admission [Na]P and Δ[Na] was demonstrated. We conclude that [Na]P falls following surgery of any severity and that such falls occur even when exogenous dilution cannot be implicated as a cause.