Clonidine premedication prevents preoperative hypokalemia.
OBJECTIVE
To test the hypothesis that clonidine premedication could prevent an increase of plasma epinephrine occurring as a result of anxiety, and a decrease of the serum potassium (K+) levels before the induction of anesthesia.


METHODS
Randomized, double-blinded study.


METHODS
University Hospital of Seoul.


METHODS
44 ASA physical status I and II patients, aged 20 to 50 years, scheduled for knee, ear, or nose surgery.


METHODS
44 patients were randomly allocated into one of two groups: 22 patients (clonidine group) received clonidine 300 microg orally at 120 minutes before the induction of anesthesia. The other 22 patients (control group) received a placebo.


RESULTS
Anxiety level, serum K+, and plasma epinephrine were measured at an outpatient clinic, and immediately before the induction of anesthesia. There were no differences between groups in degree of anxiety experienced, serum K+, or plasma epinephrine levels as measured at the out-patient clinic. Immediately before the induction of anesthesia, the serum K+ levels of the clonidine group were higher than those of the control group (3.89 +/- 0.26 mEq/L vs. 3.50 +/- 0.36 mEq/L), and anxiety and plasma epinephrine levels of clonidine group were lower than those of the control group (p < 0.05). The frequency of hypokalemia (K+ < or = 3.5 mEq/L) of the clonidine group immediately before the induction of anesthesia was significantly lower than that of the control group (0% vs. 50%).


CONCLUSIONS
Clonidine premedication was effective in preventing hypokalemic episodes occurring before the induction of anesthesia.
Hahm
Tae S
TS
Department of Anesthesiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Cho
Hyun S
HS
Lee
Kook H
KH
Chung
Ik S
IS
Kim
Ji A
JA
Kim
Myung H
MH
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage*; D000328:Adult; D000768:Anesthesia, General; D001007:Anxiety / Q000097:blood / Q000517:prevention & control*; D003000:Clonidine / Q000008:administration & dosage*; D004311:Double-Blind Method; D004837:Epinephrine / Q000097:blood; D005260:Female; D006801:Humans; D007008:Hypokalemia / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D011229:Preanesthetic Medication; D013514:Surgical Procedures, Operative / Q000523:psychology; D013565:Sympatholytics / Q000008:administration & dosage*
D000316:Adrenergic alpha-Agonists; D013565:Sympatholytics; D003000:Clonidine; D011188:Potassium; D004837:Epinephrine