Sevoflurane in Cardiac Surgery

Background

It is commonly believed that the choice of the primary anesthetic agent does not result in different outcomes after cardiac surgery. Recent evidence however has indicated that volatile anesthetics improve post-ischemic recovery. These results have been summarized in a meta-analysis of 22 randomized studies, involving 1922 patients: the use of volatile anesthetics was associated with significant reductions of myocardial infarctions (24/979 [2.4%] in the volatile anesthetics group vs 45/874 [5.1%] in the control arm, odds ratio [OR]=0.51 [0.32-0.84], and mortality (4/977 [0.4%] vs 14/872 [1.6%], OR=0.31 [0.12-0.80].

Furthermore, the use of volatile anesthetics was associated with shorter intensive-care unit stay (WMD=-7.10 hours [-11.47; -2.73], and time to hospital discharge (WMD=-2.26 days [-3.83; -0.68].

All the studies of the meta-analysis included low risk patients undergoing isolated procedures (mostly coronary artery bypass grafting).

Objectives

Investigators are planning a large multicentre randomized controlled study to confirm the beneficial cardioprotective effects of volatile anesthetics in cardiac surgery as indicated by a reduced intensive care stay and/or death in an high risk population of patients undergoing combined valvular and coronary procedures. Secondary endpoints will be: cardiac troponin release; incidence of myocardial infarction; time on mechanical ventilation; postoperative hospital stay

Methods

Various centers will randomize 200 patients to receive either a total intravenous anesthesia with propofol or an anesthesia with sevoflurane. All patients will receive a standard middle dose opiates anesthesia. All the perioperative management will be otherwise identical and standardized. Transfer out of the intensive care will be performed with SpO2 94% or greater at an FiO2 of 0.5 or less by facemask, adequate cardiac stability with no hemodynamically significant arrhythmias, chest tube drainage less than 50 ml/h, urine output greater than 0.5 ml/kg/h, no intravenous inotropic or vasopressor therapy in excess of dopamine 5 ug/kg/min, and no seizure activity.

Expected Results

The reduced cardiac damage (reduction in cardiac troponin release and in the incidence of myocardial infarction) will translate into a better tissue perfusion and faster recovery as documented by reduced intensive care unit.

Inclusion criteria

• age >18 years
• written informed consent
• scheduled procedures

Exclusion criteria

• ongoing acute myocardial infarction
• cardiac troponin >1 ng/ml
• previous unusual response to an anesthetic
• use of sulfonylurea, theophylline or allopurinol
• thoracotomy