Blood biochemistry following endoscopic third ventriculostomy

Endoscopic third ventriculostomy (ETV) is now an accepted treatment for obstructive hydrocephalus. Anandh et al. have reported postoperative hyperkalemia following ETV. However, due to small sample size (20 patients), the authors could not confirm their hypothesis (8). Therefore, we have conducted the present study in order to investigate postoperative blood chemistry following ETV.

The computerized database and the medical records of 50 patients who underwent ETV under general anesthesia were studied. Blood chemistry for all patients was done preoperatively as well as for three consecutive days postoperatively. Preoperative and peak postoperative serum blood chemistry variables were compared by using Student's t-test for paired samples. A p value of < 0.05 was considered significant.

Preoperative serum K+ concentration mean value was 4.8 +/- 0.7 mmol/l. In the consecutive two postoperative days serum K+ levels mean values were 4.4 +/- 0.8 and 4.3 +/- 0.8 mmol/l with significantly lower levels compared to preoperative values (p < 0.05).

Although significantly lower K+ values have occurred in our series postoperatively, they were of no clinical significance. Moreover, our results were in contrast to Anandh et al. who used lactated Ringer's (LR) as irrigation fluid which led to postoperative hyperkalemia. We recommend the use of normal saline as irrigation fluid instead of LR.