Original Articles
Does isoflurane optimize myocardial protection during cardiopulmonary bypass?*

https://doi.org/10.1053/jcan.2001.24954Get rights and content

Abstract

Objective: To investigate the possible myocardial protective effect of isoflurane during aortic cross-clamp and cardioplegic cardiac arrest in patients undergoing conventional coronary artery bypass graft surgery. Design: Prospective, randomized. Setting: University medical center. Participants: Forty-nine patients undergoing elective coronary artery bypass graft surgery divided into 2 groups: control group (n = 21) and isoflurane group (n = 28). Intervention: Isoflurane was administered in the pre-cardiopulmonary bypass (CPB) period to the isoflurane group. Measurements And Main Results: Hemodynamics and ST- segment variations were monitored in the pre-CPB period and after weaning from CPB in both groups. Incidence of reperfusion arrhythmias after release of aortic cross-clamp was compared. In the isoflurane group, the mean cardiac index after CPB was significantly higher than the pre-CPB value, whereas no difference between the 2 values was found in the control group. The higher cardiac index in the isoflurane group was associated with a lesser degree of ST- segment changes than in the control group. There was no significant difference between the 2 groups in the incidence of reperfusion arrhythmias after release of aortic cross-clamp. Conclusion: The present report suggests that administration of isoflurane before aortic cross-clamping in patients undergoing coronary artery bypass graft surgery may optimize the myocardial protective effect of cardioplegia. Isoflurane may be particularly advantageous whenever prolonged periods of aortic cross-clamping or inadequate delivery of cardioplegia is expected. Copyright © 2001 by W.B. Saunders Company

Section snippets

Methods

Forty-nine patients undergoing elective CABG surgery with CPB were prospectively studied after approval of the institutional review committee. Exclusion criteria included diabetes mellitus, recent myocardial infarction (<1 month), unstable angina, renal failure, and prior CABG surgery. Patients were randomly assigned into 2 groups: Group I (28 patients) received isoflurane during the pre-CPB period. Group II (21 patients) served as a control with no inhalation anesthetic administration.

Patients

Results

The control and isoflurane groups were matched for age, sex, body surface area, and number of coronary arteries grafted (Table 1).

. Demographics in the Isoflurane Group and Control Group

Empty CellControl Group (n = 21)Isoflurane Group (n = 28)
Age (y)60.9 ± 10.357.1 ± 8.6
Sex ratio (M/F)16/522/6
BSA1.9 ± 0.11.9 ± 0.2
No. grafts2.7 ± 0.62.8 ± 0.6

NOTE. Values are mean ± SD. No significant difference was found between the 2 groups.

Abbreviation: BSA, body surface area.

The operative conditions were similar for both

Discussion

Clinically, the APC effect of isoflurane has been investigated in patients undergoing CABG surgery; the data support a cardioprotective effect of isoflurane as evidenced by a trend of consistently lower levels of CK-MB and troponin, which are sensitive markers of cellular necrosis.17 These findings may explain the present clinical results in patients undergoing CABG surgery, which show that the mean CI after weaning from CPB was significantly higher than the pre-CPB value in the isoflurane

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  • Myocardial protection by volatile anesthetics in patients undergoing cardiac surgery: A critical review of the laboratory and clinical evidence

    2013, Journal of Cardiothoracic and Vascular Anesthesia
    Citation Excerpt :

    In contrast to these findings, other investigators' results suggested that APC may indeed occur in patients undergoing CABG. For example, Haroun-Bizri et al demonstrated that administration of isoflurane to 28 elective CABG patients before cardiopulmonary bypass attenuated ST-segment changes and improved cardiac index compared with 21 controls who did not receive the volatile anesthetic.41 Meco et al used a preconditioning protocol in which 28 CABG patients were exposed to 2.5 MAC desflurane or placebo for 5 min followed by a 10-min anesthetic elimination period before aortic cross-clamping and cardioplegic arrest.42

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*

Address reprint requests to Anis Baraka, MD, FRCA, Department of Anesthesiology, American University of Beirut, PO Box 113-6044, Beirut, Lebanon. E-mail: [email protected]

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