Effect of remifentanil on systemic vascular resistance in patients undergoing cardiopulmonary bypass / 中华麻醉学杂志

ABSTRACT

Objective To investigate the mechanism by which remifentanil decreases blood pressure during cardiopulmonary bypass (CPB).Methode Twenty-six ASA Ⅱ or Ⅲ patients (NYHA's classification grade Ⅱ or Ⅲ ) of both sexes and aged 20-55 years were randomized to receive remifentanil (group R, n = 13) or normal saline (group C, n = 13). Remifentanil 10 μg/kg or equal volume of normal saline was administered via a venous reservoir when cardiac arrest was induced with cardioplegic solution. The flow rate resistance (SVR) were measured and arterial blood samples were taken for determination of plasma concentrations of histamine,nitric oxide (NO) and 6-keta-prostaglandin F1α(PGF1α) before T0 and at 5, 10, 15 min (T5.10.15) after remifentanil administration.Results Remifentanil administration was associated with a significant decrease in MAP and SVR at T5 and T10 as compared with the baseline values at T0 ( P ＜ 0.05); whereas in control group, MAP and SVR were significantly increased at T5, T10 and T15 as compared with the baseline values at T0 . There were no significant differences in plasma histamine, NO and PGF1α concentrations between the two groups.Conclusion Remifentanil reduces SVR and causes a decrease in BP but without altering plasma concentrations of histamine, NO or PGl2.