Effects of ulinastatin preconditioning on protamine-induced pulmonary injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass

Abstract

Objective To evaluate the effects of ulinastatin preconditioning on protamine-induced pulmonary injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Sixty NYHA class Ⅱ or Ⅲ and ASA physical status Ⅱ or Ⅲ patients of sexes,aged 21-59 yr,scheduled for elective cardiac valve replacement under CPB,were randomly divided into 3 groups (n =20 each):group control one protamine given via central vein (group C1) ; group control two protamine given via ascending aorta (group C2) ;group ulinastatin preconditioning (group U).Heparin was neutralized with protamine after termination of CPB.Ulinastatin 20 000 U/kg was infused via the central vein at a rate of 500-1000 U· kg-1 · min-1 starting from the time point after tracheal intubation until 10 min before cross-clamping of superior vena cava and inferior vena cava in group U.At 10 min after termination of CPB,protamine 4 mg/kg was infused over 8 min via the right internal jugular vein in groups C1 and U,or via the aortic root in group C2.Blood samples were obtained from the left atrium and right atrium at 5 min before neutralization of heparin with protamine (T1) and 15 min after neutralization of heparin with protamine (T2) for determination of polymorphonuclear leukocyte (PMN) and platelet (Plt) counts,and plasma concentrations of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1α (6-keto-PGF1α).Blood samples were obtained from the left atrium at T1 and T2 for determination of the levels of TNF-α,IL-1,IL-8,CD11b/CD18,C3a,C5a,and malondialdehyde (MDA) and superoxide dismutase (SOD) activity and for blood gas analysis.Alveolar-arterial oxygen gradiant (A-aDO2),respiratory index (RI) and oxygenation index (OI) were calculated.Pulmonary arterial pressure (PAP) was recorded.Results Plt and PMN counts in the blood obtained from the left atrium were significantly lower,and plasma TXB2 concentrations in the blood obtained from the left atrium were higher at T2 in group C1,and the plasma 6-keto-PGF1α concentrations and SOD activity in the blood obtained from the left atrium were higher at T2 in groups C2 and U than those in the blood obtained from the right atrium (P ＜0.05).Compared with group C1,Plt and PMN counts and plasma 6-keto-PGF1α concentrations were significantly increased,the levels of plasma TXB2,TXB2/6-keto-PGF1α,TNF-α,IL-1,IL-8,C3a,C5a and MDA were decreased,CD11b/CD18 expression was down-regulated,PAP,A-aDO2 and RI were decreased,and OI was increased at T2 in C2 and U groups (P ＜ 0.05).There were no significant differences in the parameters mentioned above between groups C2 and U (P ＞ 0.05).Conclusion Ulinastatin preconditioning can inhibit protamine-induced pulmonary injury in patients undergoing cardiac valve replacement under CPB,and the effect is similar to that of protamine administered via the aorta. Key words: Trypsin inhibitors; Respiratory distress syndrome, adult; Protamine; Cardiopulmonary bypass; Heart valve prosthesis implantation; Preconditioning