It is important to establish a stable haemodynamics in patients undergoing cardiac surgery. Haemodynamic depression is common during induction of anaesthesia [1]. Sympathetic response due to tracheal intubation creates unwanted hypertensive responses on haemodynamics. Dexmedetomidine decreases stress responses and may provide a stable haemodynamics in situations such as surgery or induction of anaesthesia [2-4]. It may increase the tendency to hypotension and bradycardia by weakening the hyperdynamic response caused by sympathetic effect [5,6]. Concurrent use of dexmedetomidine may reduce anaesthetic opioid doses and provide more stable haemodynamics on systolic arterial pressure in patients undergoing CABG [7].

During cardiopulmonary bypass, dexmedetomidine may provide myocardial protection by exerting anti-inflammatory effects and may be beneficial for rapid recovery [6,8,9]. In cardiac surgery, dexmedetomidine provided bidirectional regulation of the anti-inflammatory response in which it showed antioxidant properties by inhibiting proinflammatory cytokine production and lipid peroxidation [10,11]. Dexmedetomidine in combination with propofol resulted in lower myocardial enzyme values than propofol alone [12]. The cardioprotective effects of propofol are dose-dependent; however, haemodynamic instability may be a concern at higher doses. In addition, dexmedetomidine may be considered a valid alternative to propofol, mainly because of its haemodynamic stability and possible myocardial protective effects [13]. It has been shown that dexmedetomidine pretreatment in valvular heart surgery can reduce the dose of propofol and the duration of mechanical ventilation and provide myocardial protection without an increase in adverse events [14]. Our study had two aims. The first was to provide a more stable haemodynamics by adding dexmedetomidine to induction in open cardiovascular surgery anaesthesia. Hypotension during induction and hypertensive response during tracheal intubation were tried to decrease. The second was to evaluate the effect of dexmedetomidine on cardiac enzymes only during induction, i.e. to evaluate its cardiac protective efficacy.

Inclusion Criteria:

• Patients over 18 years of age who underwent cardiovascular surgery (coronary artery bypass grafting, valve replacement or total aortic arch replacement) for ischaemic heart disease, valvular disease or aortic arch aneurysm were included.

Exclusion Criteria:

• Severe cardiovascular disease [(NYHA class 4 or left ventricular ejection fraction (LVEF) less than 30%)] ,
• Concomitant systemic disorders (e.g. patients with severe liver dysfunction or chronic renal failure on haemodialysis),
• Pregnant women,
• Emergency cases