The Influence Of High Flux Hemodialysis On Residual Renal Function Of Maintenance Hemodialysis Patients

Objective:Residual renal function (RRF) is the filtration and endocrine function of residual renal tissue after kidney is destroyed. RRF is very important for hemodialysis patients,but it will gradually decrease over time.Through observing the influence of high flux hemodialysis (HFHD) and low flux hemodialysis (LFHD) on RRF of maintenance hemodialysis (MHD) patients,we confirm whether HFHD is better than LFHD on protecting RRF.Method:We selected twenty-four uremic patients who dialysed in the hemopurification center of Fourth hospital of Hebei Medical university from 2006.1 to 2006.12,among them there were 18 men and 6 women. Permission criterion:1 Dialys is time had been beyond 3 months;2 All of patients adopted pol- ysulphone dialysis membrance;3 Blood pressuer was steady in both intradialysis and interdialysis,neither hypertension nor hy- potension occurred;4 No nephrotoxins were applied,no hyper- protein and hyperlipid diet was eaten;5 No large proteinuria;6 No infection and heart failure occurred.The patients were rando- mly devided into two groups: HFHD and HFHD group . In HFH D group:twelve patients:five Chronic glomerulonephritis; two benign arteriolar nephrosclerosis;one polycystic kidney disea- se ;one IgA nephrology;one Alport syndrome;two diabetic neph- rology.The age was from 38 to 75years old, the average age was 62.3 years old, dialysis time was from 4 to 46 months,the average dialysis time was 19 months, F60 polysulphone dial- yzer with ultrafiltration coefficient of 40ml/h·mmHg and an area of 1.3m2, three times per week,time for dialysis session was 4-4.5 hours; In LFHD group: twelve patients:5 Chronic glomeru lonephritis; two benign arteriolar nephrosclerosis;one drug-int- errelated kidney disease; one polycystic kidney disease ;two IgA nephrology; two diabetic nephrology.The age was from 27 to 76 years old, the average age was 51.6 years old, dialysis time was from 3 to 22 months, the average dialysis time was 17 mo- nths, F6 polysulphone dialyzer with ultrafiltration coefficient of 5.5ml/h·mmHg and an area of 1.3m2, three times per week,time for dialysis session was 4-4.5 hours. During the period of tr- ial ,one patient was dead,three patients dropped from the trial,among them two patients converted to other hospital,one patient operated transplant. At last 20 patietnts completed the trial.Ther- e were 10 patients in HFHD and LFHD group respectively.In tw o groups, all patients adopted internal arteriovenous fistula, dial- ysis solution was carbonate dialysis solution , the blood flow was 250 ml/min and the dialysate flow was 500ml/min. The dialysis machine was Fresenius 4008S. Average reuse times of F60 dialyzer was 10, average reuse times of F6 dialyzer was 6. Disinfector was Renalin. In order to confirm there was no brine and heparin before gather blood sample ,the blood sample of predialysis was gained from the artery tubule before connected artery tubule and washed the needle.The blood sample of post- dialysis was gained from the artery tubule after hemodialysis was over ,blood flow rate decreased to 50 ml/min before the blood sample was gained from the artery tubule that was closest to the patients.2 ml blood was gathered once.We collected all of urine interdialysis, urine was antisepticised by xylene,we recor- ded urine volume and kept back the mixed urine sample for examination, recorded interdialysis time(precise to minute). The consistency of creatinine and urea in both blood and urine was examinated by conventional biochemistry method.According to the equation:KRU(residual renal urea clearence rate)(ml/min) = 2(UID×VID)/TID(Cpos+Cpre),we calculated RRF at zero mo- nth and after 6 months respectively. UID represents the consist- ency of urea in urine interdialysi(smmol/l).VID represents urine volume interdialysis(ml).TID represents time interdialysis(min), Cpos represents blood urea consistency of postdialysis(mmol/l), Cpre represents blood urea consistency of predialysis next ti- me(mmol /l).Likely,we can also calculated RRF according to creantine consistency. However because urea could be rea- dsorbed by renal small tubule and creatnine was excreted by renal small tubule while RRF was low, RRFurea and RRFcreatinine was influenced,so we calculated RRF according to creantine and urea respectiv- ely,then calculated the average which represents RRF,this could eliminate error maximumly.In addition,we collected blood sample to examinate serum phosphorus,CHOL and TG,in order to confirm the influence of HFHD and LFHD on serum phosphorus,CHOL and TG.Result:1 At zero month, RRF was similar between HFHD and LFHD group(1.57±1.09,1.50±1.22),there was no statistical significanc- e(P>0.05). RRF after 6 months was obvious lower than that at zero month in LFHD group(1.50±1.22,0.538±0.410),there was statistical significance(P<0.05). RRF after 6 months was also obvious lower than that at zero month in HFHD group (1.57±1.09,1.167±0.810),there was statistical significance(P<0.05). A- fter 6 months ,RRF was obvious difference between HFHD and LFHD group(1.167±0.810,0.538±0.410),there was statisticals- ignificance(P<0. 05).After 6 months ,the declining rate of RRF was obvious lower in HFHD group than in LFHD group(0.269±0.086,0.575±0.1 58),there was statistical signifycance(P <0. 05).2 Linerelation analysis showed: There existed plus relationship between urine volume and RRF (r=0.8141).Linear regression equation was as follow: Y=0.4813+0.0026X,Y repressents RR F,X represents urine volume of 24 hours.3 Linerelation analysis showed: There existed minus relatioship between dialysis time and RRF (r=-0.5535).4 At zero month, the consistency of serum phosphorus,TG and CHOL was similar between HFHD and LFHD group (1.924±0.2 31, 2.035±0.351), (1.476±0.521,1.603±0.415),(3.901±0.651, 4.036±0.318),there was no statistical significance(P>0.05).After 6 months , the consistency of serum phosphorus,TG and CHOL in HFHD group was obvious lower than that in HFHD group (1.616±0.312,1.991±0.286)(0.841±0.471,1.651±0.472),(3.8145±0.801,4.701±0.735),there was statistical significan- ce(P<0.05).Conclusion:1 RRF decrease in the course of hemodialysis,but the declining rate is obvious lower in HFHD group than in LFHD group,this hint HFHD is better than LFHD on protecting RRF.2 HFHD can decrease the level of serum phosphorus,TG and CHOL in hemodialysis patients.3 We can cursorily assess RRF in hemodialysis patients acco- rding to urine volume.