心内直视手术中地塞米松的心肌保护作用

Protective effects of dexamethasone on myocardium in patients undergoing open heart surgery

目的 :观察地塞米松对心内直视手术心肌缺血再灌注一氧化氮 (NO)及氧自由基 (OFR)导致心肌细胞损伤的保护作用。方法 :1 6例心内直视手术者 ,随机分为对照组 ( 组 ,8例 )和地塞米松组 ( 组 ,8例 )。 组于主动脉阻断前 2 0分钟静注地塞米松 0 .4m g/ kg, 组给等容量平衡液。 2组分别于主动脉阻断前、阻断 30分钟及开放后 30分钟采血 ,测定血浆 NO、丙二醛 (MDA)含量 ,肌酸磷酸激酶 (CPK)、乳酸脱氢酶 (L DH)活性。结果 :心肌缺血再灌注期间 , 组 NO、MDA、CPK及 L DH较 组显著降低 ,开放后 30分钟 ,NO 组 (77.2±2 1 .7)μmol/ L , 组 (5 7.0± 1 6 .3)μm ol/ L ,P<0 .0 5。阻断 30分钟 ,MDA 组 (4.92± 0 .79)μm ol/ L , 组 (4.0 0± 0 .32 )μmol/ L ,P<0 .0 1 ;开放后 30分钟 , 组 (7.32± 0 .48)μm ol/ L , 组 (4.94± 1 .1 8)μm ol/ L ,P<0 .0 0 1。阻断 30分钟 ,CPK 组 (2 5 .40± 3.6 9) U/ L , 组 (2 1 .30± 3.34 ) U / L ,P<0 .0 5 ;开放后 30分钟 , 组 (97.80±1 3.90 ) U/ L, 组 (44 .90± 9.73) U/ L,P<0 .0 0 1。阻断 30分钟 ,L DH 组 (3.6 9± 0 .5 6 ) μmol· s- 1· L- 1 , 组(2 .92± 0 .44 ) μmol· s- 1· L- 1 ,P<0 .0 1 ;开放后 30分钟 , 组 (4.74± 0 .34 ) μm ol· s-

Objective:To observe the protective effect of dexamethasone (DXM) on myocardial injuries induced by nitric oxide (NO) and oxygen free radicals (OFR) from ischemiareperfusion in patients undergoing open heart surgery.Methods:16 patients were randomly divided into control group ( n =8) and treatment group ( n =8).Patients in treatment group were given DXM 0 4 mg/kg intravenously 20 minutes prior to occlusion of the aorta while those in control group received the same volume of balanced saline.Plasma levels of NO,malondialdehyde (MDA),creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) were measured before the occlusion of aorta,30 minutes of occlusion and 30 minutes after release,respectively.Results:There was no significant difference in all parameters studied between two groups before clamping of aorta.During myocardial ischemiareperfusion,plasma levels of NO,MDA,CPK and LDH were much higher in control group than those in treatment group ( P <0 05 or P <0 001).Conclusions:DXM could effectively attenuate lipid peroxidation and protect myocardium from ischemia and ischemiareperfusion by reducing tissue production of NO and OFR.