We are trying to investigate whether intraoperative dexmedetomidine infusion could decrease the incidence of intraoperative hypokalemia and arrhythmia, and myocardial injury in patients undergoing off-pump coronary artery bypass graft, and trying compare these effects with those of remifentanil infusion.
Alpha2-adrenergic agonist, dexmedetomidine, is recently used for sedation, analgesia or adjuvant to general anesthesia. Postsynaptic activation of alpha2 adrenoceptors in the central nervous system (CNS) inhibits sympathetic activity and thus can decrease blood pressure and heart rate. The blockade of sympathetic activity decrease the neuroendocrine stress response and may decrease the incidence of hypokalemia. The hypokalemia can increase the incidence of arrythmia, especially in cardiac patients. We postulated that dexmedetomidine could decrease the neuroendocrine stress response, thus decrease arrhythmia during cardiac surgery. Furthermore, dexmedetomidine have been reported to have cardioprotective effect with previous animal studies. Therefore, the aim of the present study is to investigate whether the intraoperative dexmedetomidine infusion can reduce the incidence of hypokalemia and arrythmia, and myocardial injury in subjects undergoing off-pump coronary artery bypass graft. We are also trying to compare these effects with those of remifentanil infusion.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Masking
SINGLE
Enrollment
77
Dexmedetomidine infusion 0.2 mcg/kg/hr during anesthetic induction 0.3 - 0.7 mcg/kg/hr during the surgery
Remifentanil infusion 0.05 - 0.3 mcg/kg/min during the anesthetic induction and surgery
Samsung Medical Center
Seoul, South Korea
serum potassium concentration
serum potassium concentration at the day before anesthetic induction
Time frame: at 24 hour before anesthetic induction
serum potassium concentration
1 minutes before anesthetic induction (etomidate injection)
Time frame: 1 minutes before anesthetic induction
serum potassium concentration
serum potassium concentration 20 minutes after start of anesthetic induction (at the end of anesthetic induction)
Time frame: 20 minutes after start of anesthetic induction
serum potassium concentration
serum potassium concentration at 2 hour after anesthetic induction (after mammary artery dissection and graft formation)
Time frame: 2 hour after the start of anesthetic induction
serum potassium concentration
serum potassium concentration at 3 hour after end of anesthetic induction (after the anastomosis of coronary graft)
Time frame: 3 hour after start of anesthetic induction
arterial blood gas analysis results
arterial blood gas analysis results
Time frame: 24 hour, 1 min before anesthetic induction, 20 min, 2 and 3 hour after the start of anesthetic induction
incidence of hypokalemia
incidence of hypokalemia (serum K \< 3.5) incidence of hypokalemia (serum K \< 4.5)
Time frame: 24 hour, 1 min before anesthetic induction, 20 min, 2 and 3 hour after the start of anesthetic induction
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hemodynamic parameters
hemodynamic parameters (blood pressure, heart rate, central venous pressure, cardiac output, SvO2)
Time frame: 24 hour, 1 min before anesthetic induction, 20 min, 2 and 3 hour after the start of anesthetic induction
inotropics, vasopressor requirement
inotropics, vasopressor requirement
Time frame: 24 hour, 1 min before anesthetic induction, 20 min, 2 and 3 hour after the start of anesthetic induction
Myocardial injury marker
serum concentration of CK-MB, Troponin (i)as a marker for myocaridial injury
Time frame: 2, 24, 48 hour after the end of surgery
Left ventricular function
left ventricular function determined by Tei index, ejection fraction of preoperative, intraoperative, postoperative echocardiography
Time frame: 72 hour before, during (immediate after grafting), 72 hour after surgery