Maintenance Hemodialysis Patients With Blood Pressure And Its Influencing Factors, Single-center Study

Background: As an important risk factor for cardiovascular diseases,hypertension prevails in chronic hemodialysis(HD) patients and is difficult to control.Further, intradialytic hypotension and hypertension bring patients additional risks andresult in hemodialysis inadequacy.Objectives: (1) To estimate the prevalence of hypertension, overview theanti-hypertensive medication, and observe the change of blood pressure over time inchronic hemodialysis patients in our hemodialysis center. (2)To elucidate potentialcontributing factors of hypertension in HD patients. (3) To evaluate the frequency ofepisodes of intradialytic hypotension and hypertension.Methods: (1) Cross sectional study including 164 hemodialysis patients wasperformed in our hemodialysis center in March 2007. Blood pressure, pre-dialysisheart rate, ratio of weight loss during dialysis and estimated dry weight(WL/EDW),KT/V, weekly dosage of rHuEPO, Hgb, serum sodium and serum calcium wererecorded and averaged over a three month period. T-test and multifactorial regressionwere performed to identify the predicting factors of hypertension. (2) Intradialytichypotension or intradialytic hypertension events were recorded in 5503 dialysis visitsof all the subjects from Jan 2007 to March 2007. T-test and Logistic regression wereperformed to sort out the predicting factors of intradialytic hypotension orintradialytic hypertension.Results:(1) Hypertension had a prevalence of 91%in chronic hemodialysis patients inour hemodialysis center and only 24% hypertensive patients was well controlled.Average 3±1 antihypertensive drugs were used for each hypertensive patient andcalcium channel blockers were used in 75% of the patients.(2) Age (P=0.004) was negatively correlated with pre-dialysis Mean ArterialPressure(MAP), while amount of antihypertensive drugs used(P＜0.01) and pre-dialysis heart rate(P=0.020) were positively. Age(P＜0.01) and WL/EDW(P=0.034)were negatively correlated with post-dialysis MAP, while amount of antihypertensivedrugs used.(3) The incidence of intradialytic hypotension was 12.7% and was significantlyhigher in the patients older than 65 (14.4%). 50% episodes occurred during the firsthour of hemodialysis. Both T test and Logistic regression identified higher WL/EDWand higher pre-dialysis MAP as predicting factors of intradialytic hypotension(P＜0.01).(4) The incidence of intradialytic hypertension was 1.1%, and was significantlyhigher in the patients younger than 45 (3.2%). 47.5% episodes occurred at the end ofhemodialysis. Both T test and Logistic regression revealed faster heart rate and lowerpre-dialysis MAP as predicting factors of intradialytic hypertension (P＜0.01).Conclusion:(1) Hypertension had a high prevalence in chronic hemodialysis patients in ourhemodialysis center.(2) Fluid overload played a important role in hypertension of HD patients, andsympathetic hyperactivity might be related to hypertension.(3) age≥65, higher pre-dialysis MAP and weight loss during hemodialysismight be the predicting factors of intradialytic hypotension.(4) age＜45, faster heart rate and lower pre-dialysis MAP might be thepredicting factors of intradialytic hypertension.