[Remifentanil preconditioning lowers cardiac troponin I levels in patients undergoing off-pump coronary artery bypass graft surgery].

ABSTRACT

OBJECTIVE: To investigate the value of cardiac troponin I (cTnI) levels in assessing myocardial protection by remifentanil precondition against myocardial injury induced by off-pump coronary artery bypass (OPCAB). METHODS: Twenty-four patients undergoing OPCAB were randomized into control and remifentanil preconditioning group (n=12). All the patients received pretreatment with oral diazepam (10 mg), intramuscular morphine (10 mg) and hyosine (0.3 mg). General anesthesia was induced with midazolam (0.08 mg/kg), etomidate (0.1-0.3 mg/kg), fentanyl (5-10 microg/kg), and rocuronium (1 mg/kg), and maintained with isoflurane inhalation and propofol infusion. Intermittent fentanyl and pipecuronium were given intravenously. In remifentanil preconditioning group, remifentanil (5 microg/kg in 50 ml normal saline) was infused in 10 min after anesthesia induction, and only NS was administered in the control group. Blood samples were obtained before and at 0, 2, 6, 24, and 48 h after the operation to determine serum cTnI levels. RESULTS: In both of the two groups, the cTnI levels increased significantly at the postoperative time points (0, 2, 6, 24, and 48 h) as compared with those before the operation (P<0.05). The cTnI levels of remifentanil preconditioning group were markedly decreased after the operation in comparison with those of the control group (P<0.05). CONCLUSION: Remifentanil preconditioning decreases the cTnI levels and reduces myocardial injury induced by OPCAB.