Effects of ulinastatin on cytoldnes and respiratory index during open heart surgery with CPB

Objective To investigate the effects of ulinastatin on pro- and anti-inflammatory cytokines and respiratory index during open heart surgery under CPB. Methods Twenty ASA Ⅱ- Ⅲ patients of either sex (9 males, 11 females) scheduled for elective valve replacement under CPB were randomly divided into two groups of 10 each : control group (C) and ulinastatin group (W) . Patients with hepato-renal dysfunction or taking glucocorticoid were excluded. The patients were premedicated with intramuscular phenobarbital 0.1 g and scopolamine 0.3 mg. Anesthesia was induced with midazolam 0.1 mg·kg-1 , fentanyl 10μg·kg-1 and vecuronium 0.1mg·kg-1 . After tracheal intubation anesthesia was maintained with midazolam and fentanyl. The patients were mechanically ventilated. VT was set at 8-12 ml·kg-1 , RR 10-12 bpm and I: E 1:2. PETCO2 was maintained at 35-45 mg. In ulinastatin group, the patients received ulinastatin 12 000 U·kg-1 of which half was given i.v. before CPB and half was added to the priming fluid, while group C received normal saline instead of ulinastatin. Blood samples were taken from radial artery for determination of plasma TNF-α, IL-6, and IL-10 concentrations and blood gas analysis before operation (T1 ) , 30 min after initiation of CPB (T2), 1 h (T3 ) , 4 h (T4 ) and 24 h (T5 ) after CPB. Respiratouy index (PA-aDO2/ PaO2) was calculated at T1-5 .Results There were no significant differences in sex, age, weight, height, duration of CPB, and aortic cross-clamping time between the two groups. In group C the plasma levels of TNF-α, IL-6 and IL-10 were significantly higher than the baseline values (T1 ) during and after CPB (P0.01). In group W the plasma levels of TNF-α, IL-6 and IL-10 did not increase until T3 and returned to baseline levels (TNF-α, IL-6) or were greatly decreased (IL-10) at T5. The plasma TNF-α and IL-6 concentrations were significantly higher while the plasma IL-10 concentration was significantly lower in group C than in group W after CPB ( P0.01) . The TNF-α/IL-10 ratio and IL-6/IL-10 ratio were significantly higher in group C than in group W after CPB (P0.01) . The respiratory index in control group was significantly higher than the baseline (T1) and that in group W after CPB (P0.01 or 0.05) . Plasma IL-10 concentration and respiratory index were positively correlated with plasma concentration of TNF-α and IL-6 whereas respiratory index was negatively correlated with the plasma IL-10 level. Conclusion Our results show that ulinastatin can effectively adjust the balance between pro- and anti-inflammatory cytokines and protect respiratory function.