Dry weight evaluation in hemodialysis patients / 中华肾脏病杂志

ABSTRACT

Objective To estimate dry weight (DW) and prevent dialysis-related hypotension and hypertension with the on-line monitoring of relative blood volume (RBV) and other judgments.Methods One hundred and eight maintenance hemodialysis patients were assigned to three groups according to their blood pressurenormal blood pressure group (A group,n=43),hypotension group (B group,n=35) and hypertension group (C group,n=35).The level of hemoglobin,serum albumin,dialysis adequacy were determined.Systolic blood pressure,diastolic blood pressure,mean arterial pressure,heart rate,ultrafiltration volume,relative blood volume changes and the corresponding clinical symptoms were monitored during hemodialysis in all patients.Each of the patients was continuously monitored of the indicators above for 10-12 times.At the observing period,the inferior vena cava diameter (IVCD),brain natriuretic peptide (BNP) and cardiothoracic ratio(CTR) were measured.Then according to the monitoring results,appropriate clinical interventions were given under on-line blood volume monitoring guidance.Results (1)The shape of RBV curve in group A showed doubleexponential curve early,then down to the final linear decling ended during hemodialysis.(2)The RBV curve in group B was stable in the former two hours,then rapidly linear declined.RBV changes were significantly higher in group B than group A (P ＜ 0.05),but when changes in RBV were plotted against ultrafiltration volume,there was no significant difference in the two groups.The level of RBV reduction at which symptomatic hypotension occurred showed considerable inter-individual variability (P ＜ 0.05,coefficient of variation=0.28).(3)The RBV curve in group C slowly linear declined.At the end of dialysis,RBV changes were significantly lower in group C than group A (P ＜ 0.05).(4)The IVCD values in three groups of patients before dialysis were greater than normal,significantly decreased after the dialysis (P ＜ 0.05),but that in group B and group C were still greater than that in group A (P ＜ 0.05).The BNP values were significantly greater in three groups before and after dialysis (P ＜ 0.05),but after dialysis,the values decreased significantly than that before dialysis (P ＜ 0.05).(5)After appropriate clinical intervention were given under on-line blood volume monitoring in hemodialysis,the patients of group B controlled weight gain,and even cut dry weight,the RBV change significantly decreased at the end of dialysis and significantly reduced the incidence of hypotension events (P ＜ 0.05); When the patients of group C cut dry weight,increased ultrafiltration,the RBV change increased,the mean arterial pressure decreased significantly than before (P＜ 0.05).Conclusions (1)Hemodialysis patients with symptomatic hypotension show larger RBV decline rate in the forth hour and lager total RBV changes,which provides important information for forecasting the symptomatic hypotension in hemodialysis.(2)IVCD and CTR have certain significance to the adjustment of dry weight,but the BNP has guiding significance to volume change.(3)On-line monitoring of RBV can effectively guide the adjustment of dry weight,reduction of symptomatic hypotension occruence,and controlling of refractory hypertension in hemodialysis.