[Effects of fentanyl on cytokines and MDA during cardiopulmonary bypass in patients undergoing valve replacement]

Abstract

Objective: To investigate the effect of fentanyl on cytokines and MDA in valve replacement surgery during cardiopulmonary bypass ( CPB).

Methods: Thirty ASA II approximately III adult patients scheduled for cardial valve replacement were randomly divided into 3 groups: Group A (fentanyl 30 microg/ kg), Group B (fentanyl 60 microg/kg), and Group C (fentanyl 100 microg/kg). Anesthesia was induced with medazalam 0.1 mg/kg, fentanyl 10 microg/kg and vecuronium 0.1 mg/kg Administered intravenously. After tracheal intubation the patients were mechanically ventilated with pure oxygen. P(ET)CO2 was maintained between 35 approximately 45 mmHg. Anesthesia were maintained with fentanyl infusion combined with intermittent intravenous bolus of midazolam and vecuronium. MAP, CVP, HR, P(ET)CO2, SPO2, nasal and rectal temperature were monitored continuously. Remained dose of fentanyl was infused before the CPB. Blood Samples were taken before the operation (T1 ), before the CPB ( T2 ), 30 min after aortic declamping (T3 ) , 2 h after aortic declamping (T4 ), and 24 h (T5 ) after the operation for determination of plasma levels of tumor necrosis factor (TNF-alpha), interteukin IL-6 and IL-10, MDA.

Results: There was no significant change in the age, body weight, aortic cross-clomp time, CPB time, and operation time. Levels of TNF-alpha, IL-6, IL-10 and MDA after the CPB in the 3 groups were significantly higher compared with T, (P <0.01 ), TNF-alpha, IL-6 and MDA levels at T3, T4 were significantly lower in Group B and C than those in Group A. IL-10 levels at T4, T5 were significantly higher in Group B and C than those in Group A, but levels of TNF-alpha, IL-6, IL-10 and MDA in Group B were not significantly different compared with those in Group C. The duration of stay in the ICU and time of endotracheal extubation were significantly longer in patients of Group C than those of Group A and B.

Conclusion: CPB leads to a proinflammatory and antiinflammatory response, as well as oxygen free radicals release. Larger dose fentanyl seemed to be effective in reducing CPB-induced inflammatory response and ischemic reperfusion injury, but the effect was not dependent on dose while fentanyl dose reaching some value, at the same time the duration of stay in ICU and time of endotracheal extubation is longer.