Objective To study the short-term clinical efficacy and its possible mechanism of refractory hypertension(RH) treated by continuous veno-venous hemofiltration (CVVH) in maintenance hemodialysis (MHD) patients. Methods Thirty-four MHD patients with RH treated with CVVH enrolled in the treatment group,all these patients were treatment of 2 -3 times,each time 8 - 10 hours. Thirty MHD patients with wellcontroled blood pressure were recruited as control. Changes of blood pressure, dry weight, plasma levels of parathyroid hormone (PTH), renin ( RA), angiotensin Ⅰ , Ⅱ ( AT Ⅰ , AT Ⅱ ), aldosterone ( Ald ) were observed before and after hemodialysis. Results In the treatment group,compared with pre-treatment, the blood pressure decreased significantly with an effective rate of 64.7% and efficient rate of 100. 0%. Before treatment, plasma RA was ([1.10 ±0.25] μg/(L · h)and [0:78 ±0.26] μg/(L · h),AT Ⅰ was [0.89 ±0.21] μg/L and [ 0. 52 ± 0. 14 ] μg/L, AT Ⅱ was [ 177.68 ± 89.46 ] ng/L and [ 89. 25 ± 12. 84 ] ng/L, Ald was [72. 06 ± 11.47 ]ng/L and [ 48.92 ± 8. 65 ] ng/L, PTH was [ 306. 81 ± 69. 37 ] ng/L and [ 248.76 ± 134. 62 ] ng/L in the treatment and control group respectively. All the measurements in the treatment group were significantly higher than those in the control group (P ＜ 0. 05 ). In the treatment group, compared to pre-treatment, plasma RA significantly decreased ( [ 1.10 ± 0. 25 ]μg/ ( L · h) vs [ 0. 76 ± 0. 17 ] μg/( L · h ), as well as AT Ⅰ ( [ 0. 89 ±0.21]μg/L vs [0.50 ±0.12] μg/L),ATⅡ([177.68±89.46]ng/L vs [ 87.13±14.22] ng/L),Ald ([72.06±11.47]ng/Lvs [ 46. 01± 9. 86 ] ng/L ) and PTH ( [ 306. 81 ±69.37]ng/L vs [ 186.53 ±32.93 ] ng/L) ( P ＜ 0. 05 ). However, there was no significant changes in the above mentioned measurements between before and after hemodialysis in the control group (P ＞ 0. 05). Conclusion CVVH may be an effective methods in the treatment of MHD patients with RH, and its antihypertensive mechanisms may be that CVVH can effectively remove the excess water in the body, and reduce plasma RA, AT Ⅰ , AT Ⅱ ,Ald and PTH levels.

Objective To investigate disorders in calcium and phosphorus metabolism and abnormity in parathyroid function and their related factors in maintenance hemodialysis(MHD)patients.Methods We collected serum Hb,SCr,BUN,calcium,phosphorus,iPTH,high sensitivity C-reactive protein(hs-CRP),albumin and calculated albumin-corrected Ca and Kt/V from 198 patients with MHD in Jing'an District Central Hospital,Shanghai from Jan.2009 to Dec.2010.The calcium and phosphorus metabolism and parathyroid function were evaluated according to the guidelines of bone metabolism and controlling of bone disease in Kidney Disease Outcome Quality Initiative(KDOQI)recommended by National Kidney Foundation of the United States.198 patients were classified into the standard group(150-300 ng/L),lower than the standard group(＜150 ng/L)and higher than the standard group(＞ 300 ng/L)according to serum iPTH levels.Results In the 198 cases,110 cases were normal in serum Ac-Ca(55.6％); 118 cases were normal in serum phosphorus (59.6％); 143 cases were normal in Ca × P(72.3％); 39 cases were normal in iPTH(19.7％).All four items up to the standard were 28 cases(14.1％)among 198 cases.However,132(66.7％)patients showed lower than 150 ng/L in serum iPTH.The average serum iPTH gradually decreased with age.The senior patients demonstrated the highest average serum Hs-CRP,the lowest average serum phosphorus and the lowest albumin.There were no statistical significance in sex,hemodialysis duration,diabetes,blood pressure,Hb,Bun,SCr,Ac-Ca and Kt/V among three groups.Conclusion The disorders in calcium and phosphorus metabolism and abnormity in parathyroid function is common in the MHD patients.We should pay attention to hypofunction of parathyroid gland in the patients with MHD,which may be related to aging,malnutrition and potential infection.These findings need further investigation.