[Electrolyte imbalance in the course of the postoperative period]

The article presents the results of an investigation aimed at the assessment of electrolyte balance in patients who underwent surgical treatment. The data demonstrate that in the patients from the control group there was increased blood concentration of Na+ during the preoperative period that remained in the course of the postoperative one. Hypernatriemia was associated with decreased level of K+. Besides, hyposalivation that was maximal on the days immediate after an operation and reduced Na+ excretion together with increased K+ excretion were revealed. On the postoperative day 3 and 5 the reduction of the amount of excreted K+ that did not reach baseline level was detected. In case of midazolam administration aimed at premedication and sedation minimal changes of electrolyte balance in the patients from the experimental group were noted. There was no significant increase of the secretion of K+ and its serum level was not reduced in the course of the preoperative and postoperative periods. At the same time moderate increase in Na+ secretion to the saliva associated with its normal serum concentration was detected.