Impact of preconditioning protocol on anesthetic-induced cardioprotection in patients having coronary artery bypass surgery

Objective

Anesthetic preconditioning may contribute to the cardioprotective effects of sevoflurane in patients having coronary artery bypass surgery. We investigated whether 2 different sevoflurane administration protocols can induce preconditioning in patients having coronary artery bypass.

Methods

Thirty patients were randomly allocated to 1 of 3 groups. All patients received a total intravenous anesthesia with sufentanil (0.3 μg⁻¹ · kg· h⁻¹) and propofol as target controlled infusion (2.5 μg/mL). The control group had no further intervention; 10 minutes prior to establishing the extracorporeal circulation, patients of the sevoflurane-I group received 1 minimum alveolar concentration of sevoflurane for 5 minutes. Patients of the sevoflurane-II group received (2 times) 5 minutes of sevoflurane, interspersed by 5-minute washout 10 minutes prior to extracorporeal circulation. Troponin I was measured as marker of cardiac cellular damage.

Results

Peak levels of troponin I release were observed at 4 hours after cardiopulmonary bypass and were not affected by 1 cycle of sevoflurane administration (controls: 14 ± 3 ng/mL vs sevoflurane-I group, 14 ± 3 ng/mL). Two periods of sevoflurane preconditioning significantly reduced cellular damage compared with controls (peak troponin I level sevoflurane-II group, 7 ± 2 ng/mL).

Conclusion

These data show that sevoflurane-induced preconditioning is reproducible in patients having coronary artery bypass but depends on the preconditioning protocol used.

Abbreviations and Acronyms: APC, anesthetic-induced pharmacologic preconditioning of the heart, BNP, brain natriuretic peptide, CABG, coronary artery bypass graft, CI, cardiac index, CK, creatine kinase, CPB, cardiopulmonary bypass, CVP, central venous pressure, dP/dt_max, maximum rate of LV pressure increase, EuroSCORE, European System for Cardiac Operative Risk Evaluation, ICU, intensive care unit, IPC, ischemic preconditioning, LV, left ventricular, MAC, minimum alveolar concentration, MAP, mean arterial pressure, PKC, protein kinase C, TnI, troponin I

CTSNet classification: 1, 25, 30, 31