关键词: 肾透析, 死亡, 血pH, 肾疾病

Abstract: Background　The mortality of maintenance hemodialysis（MHD） patients is significantly higher than that of the general population.Acid-base balance disorder is one of the important factors causing protein energy consumption，inflammation，endocrine disorders and abnormal bone metabolism.Better control and maintenance of acid-base balance in the body is helpful for the survival rate of patients.Current research focuses more on the bicarbonate level before hemodialysis，however，there are relatively few studies on other indicators that affect acid-base balance，such as changes in blood pH before and after dialysis，and its impact on the clinical prognosis of MHD patients.Objective　To investigate the relationship between the blood pH difference between postdialysis and predialysis and the all-cause death and cardiovascular death in MHD patients.Methods　A total of 162 patients with stable MHD who underwent hemodialysis at the Hemodialysis Center of the People's Hospital of Ningxia Hui Autonomous Region from March 2014 to June 2014 were selected as the research subjects.General data of the patients were collected，including gender，age，dialysis age，follow-up time，serum albumin，hemoglobin，fasting blood glucose，high sensitivity C-reactive protein（hs-CRP），blood calcium，blood phosphorus，full parathyroid glands，B-type brain natriuretic peptide，creatinine，urea nitrogen，uric acid，urea clearance index（spKt/V），total cholesterol，triacylglycerol，low density lipoprotein，high density lipoprotein，serum iron，total iron binding capacity，ferritin，systolic blood pressure，diastolic blood pressure，pH before and after dialysis，CO2 before and after dialysis，HCO3- before and after dialysis.According to the median of ΔpH，patients were divided into ΔpH<0.099 5 group and ΔpH≥0.099 5 group.The patients were followed up for a long time，once per 3 months.The end of the follow-up event was the death of the patient （including all-cause death and cardiovascular disease death）.The deadline for follow-up was May 2019.Analyze the relationship between the pH difference of patients and all-cause deaths and deaths from cardiovascular diseases.Results　In the end，142 patients were enrolled，including 39 all-cause deaths and 26 cardiovascular deaths.Compared with patients in ΔpH<0.099 5 group，patients had a higher serum phosphorus，creatinine，urea nitrogen，uric acid，spKt/V and postdialysis pH in ΔpH≥0.099 5 group，but predialysis pH，postdialysis CO2 and predialysis HCO3-，all-cause mortality and cardiovascular mortality were lower.COX regression analysis showed that high sensitive CRP〔HR=3.736，95%CI（1.699，8.213），P=0.001〕，predialysis diastolic pressure〔HR=0.372，95%CI（1.699，0.760），P=0.007〕，and ΔpH〔HR=0.496，95%CI（0.252，0.974），P=0.042〕are independent risk factors for all-cause mortality.Morover，high sensitive CRP〔HR=2.464，95%CI（1.063，5.711），P=0.035〕 and ΔpH〔HR=0.412，95%CI（0.178，0.955），P=0.039〕 are independent risk factors for death from cardiovascular disease in MHD patients.Kaplan-Meier survival analysis showed all-cause deaths and deaths from cardiovascular diseases in the ΔpH≥0.099 5 group were lower than those in the ΔpH<0.099 5 group （P<0.05）.Conclusion　Patients with MHD patients with larger ΔpH have a lower risk of all-cause death and cardiovascular disease death，and more adequate correction of blood pH may help improve the survival rate of MHD patients.

Key words: Renal dialysis, Death, Blood pH, Kidney diseases