The Effect Of Different Amount Of Pre-and Post-Dilution In Continuous Vena-venous Hemofiltration Solute Clearance

Objective:To observe the effect of different dose and different pre-/post-dilution ratio in continuous vena-venous hemofiltration on the solute clearance.Method:167cases of CVVH treatment for critically ill patients were enrolled. They were randomly assigned the dose of replacement fluid at predilution4000ml/h(group Al,n=30), predilution3000ml/h and postdilution1000ml/h(group A2,n=27), predilution2000ml/h and postdilution2000ml/h (group A3,n=31) or predilution6000ml/h(group B1,n=25), predilution4500ml/h and postdilution1500ml/h(group B2,n=27), predilution3000ml/h and postdilution3000ml/h (group B3,n=26).Clinical status prior to CVVH and the technique and method of CVVH(modality,dosage,type of hemofilter,vascular access and category of anticoagulant) were recorded. Take blood samples at5min,4h and8h after the CVVH started.Test the serum creatinine。Choose7sample in every group randomly,test the serum IL-6and IL-10concentration. Analyze the variation of these concentration and solute decline rate between different groups.Results:1.Before the treatment, all groups were similar in type of hemofilter,vascular access and category of anticoagulant. 2.1n the first4hours and the second4hours, the serum Cr and IL-6decline rate of group B1,B2and B3are higher than group A1,A2and A3respectively (p<0.05).When the total amount of replacement fluid was4000ml/h or6000ml/h,the serum Cr decline rate in the second4hours was lower than in the first4hours.While the serum IL-6decline rate in the second4hours was higher than in the first4hours. With the growth of the ratio of postdilution,the serum Cr and IL-6decline rate gets higher (p <0.05).3.Althought there is no significance in the decrease of serum IL-10concentration.But we also found that in the first4hours and the second4hours, the serum IL-10decline rate of group B1,B2and B3are higher than group A1,A2and A3respectively (p<0.05).Conclusion:1.In the CVVH treatment, when the amount of replacement fluid was6000ml/h,the decline rate of serum Cr and IL-6in group B were higher than the amount of replacement fluid was4000ml/h.2. When the amount of replacement fluid was fixed,the solute decline rate increased with the increase of the postdilution fluid.3.In this research,no matter the amount of replacement fluid was4000ml/h or6000ml/h,when the pre-/post-dilution ratio was1:1,it gets the best clearance of solute.4.1t is better to prolong the duration of the CVVH to increase the clearance of the middle molecule inflammatory factors.