Remifentanil added to sufentanil-sevoflurane anesthesia suppresses hemodynamic and metabolic stress responses to intense surgical stimuli more effectively than high-dose sufentanil-sevoflurane alone

Background: Even extremely high-doses of the potent opioid, sufentanil, cannot reliably suppress stress responses to intense surgical stimuli such as sternotomy. The chemically related opioid remifentanil with its different pharmacokinetics and binding affinities for delta-and kappa-opioid receptors might be more effective in attenuating these responses. Methods: ASA I-III patients scheduled for a surgical procedure with sternotomy under balanced anesthesia (sevoflurane and sufentanil 3 mu g center dot kg(-1) bolus, 0.017 mu g center dot kg(-1) center dot min(-1) infusion) were randomized into two groups. Patients in the study group were supplemented with remifentanil (2 mu g center dot kg(-1) bolus, 2-7 mu g center dot kg(-1) center dot min(-1) infusion) starting ten minutes before sternotomy. Heart rate, arterial blood pressures, cardiac index, ejection fraction, systemic vascular resistance index (SVRI), total body oxygen uptake (VO2) and electric dermal response were measured and compared between the groups. Results: 62 patients were studied (study group 32, control group 30). Systolic and mean arterial blood pressures, SVRI, VO2 and skin conductance increased during sternotomy and sternal spread in the control group but not in the study group. Systolic blood pressure increase: 7.5 +/- 19 mmHg vs. -3.4 +/- 8.9 (p = 0.005); VO2 increase: 31 +/- 46% vs. -0.4 +/- 32%; incidence of systolic blood pressure increase greater than 15 percent: 20% vs. 3% (p = 0.035) (control vs. study group). Conclusion: High-dose remifentanil added to sevoflurane-sufentanil anesthesia suppresses the sympathoadrenergic response to sternotomy and sternal spread better than high-dose sufentanil alone.