Prevention of Hypokalemia before Induction of Anesthesia by Clonidine or Midazolam

Cho, Hyun Sung; Lee, Jeong Jin; Lee, Sang Min; Chung, Ik Soo; Kim, You Hong; Choi, Duck Hwan; Shin, Byung Seop

Abstract

BACKGROUND: Selective 2-agonists cause decrease in serum K+ concentration. Midazolam is an anxiolytic, sedative, and amnestic drug. Premedication of midazolam prevents increase of catecholamine with anxiety. Clonidine, alpha 2-adrenergic receptor agonist, supresses sympathetic outflow from central nervous system. So we can expect that premedication of clonidine or midazolam will prevent hypokalemia before induction of anesthesia.
METHODS
Twenty two patients received 300 mcg clonidine per oral, 22 patients 0.05 mg/kg midazolan IM and 22 patients had no premedication. We measured serum K+ level at out-patient Department (T1), at 11:00 P.M. of the day before surgery (T2) and immediately before induction of anesthesia (T3).
RESULTS
Serum K+ levels at T2 decreased compared to serum K+ level at T1 in all groups. Serum K+ levels T3 decreased compared to serum K+ level at T2 in control and midazolam groups but clonidine group did not decrease in serum K+ level.
CONCLUSIONS
We can not prevent decrease of serum K+ level with premedication of midazolam but we can prevent decrease of serum K+ level with premedication of clonidine. So premedication of clonidine is more effective than midazolam in prevention of hypokalemia before induction of anesthesia.