透析液钠浓度与钠梯度对维持性血液透析患者的影响

The impact of sodium concentration in dialysate and sodium gradient on maintenance hemodialysis patients

目的维持性血液透析（MHD）患者心血管发病率及死亡率高,其危险因素包括水负荷过重,临床上常表现为透析间期体质量增长（IDWG）过多。钠梯度为透析液钠浓度与透析前血清钠浓度的差值,本研究拟研究钠梯度与MHD患者水负荷关系。方法选取2013年3~12月在四川省人民医院血液净化中心维持性血液透析的患者81例,血液透析3次/周,尿量〈500ml/天。收集患者期间透析前及透析后血清钠数据、钠梯度、IDWG、IDWG%及透析中低血压的发生率。结果所有患者透析前血清钠浓度为[138.81±3.27（130.2~145.0）]mmol/L,透析后血清钠浓度为[137.81±2.88（132.5~146.0）]mmol/L,透析液钠浓度为135mmol/L,钠梯度绝对值为[3.92±2.69（0~10.0）]mmol/L,透析前后钠浓度差绝对值[2.79±2.14（0.1~8.6）]mmol/L,IDWG为[2.06±0.82（0.50~4.20）]kg,IDWG%为[3.71±1.42（1.01~8.42）]%。钠梯度绝对值与IDWG及IDWG%均显著相关（r=0.349,P=0.001;r=0.269,P=0.013）,钠梯度绝对值为0时,MHD患者IDWG最低,透析对患者的钠负荷及水负荷影响最小。年龄与透析前钠浓度、钠梯度绝对值、IDWG及IDWG%显著负相关。低血压的发生率与钠梯度绝对值、IDWG等无显著相关。结论维持性血液透析患者钠梯度绝对值与IDWG显著正相关,对MHD患者透析液钠浓度的个体化处方,可能改善MHD患者的水负荷。

Background Maintenance hemodialysis （MHD） patients are associated with higher incidence of cardiovascular morbidity and mortality, for which the risk factors include hypertension, overhydration, etc. More interdialytic weight gain （IDWG） usually reflects water overload in MHD patients. Sodium gradient is defined as the difference of sodium concentration in dialysate and in predialysis serum. We hypothesize that lower absolute sodium gradient is associated with lower IDWG, and try to figure out the correlation of sodium gradient with water load and interdialytic hypotention in MHD patients. Methods We conducted a retrospec- tive study on 81 MHD patients in our hemodialysis center from Mar. to Dec. in 2013. Basic clinic data, predi- alysis and postdialysis serum sodium concentrations, sodium gradient, IDWG, IDWG% （IDWG/dry body weight× 100%）, and the prevalence of interdialytic hypotension were recorded and analyzed. Results The di- alysate sodium was 135 mmol/L for all patients, and the predialytic serum sodium was 138.81-4-3.27 （130.2~ 145.0） mmol/L with the absolute sodium gradient of 3.92±2.69 （0~ 10.0） mmol/L. IDWG and IDWG% were 2.06±0.82 （0.50~4.20） kg, and 3.71±1.42 （1.01 ~8.42） %, respectively. The absolute sodium gradient was positively correlated with IDWG （r=0.349, P=0.001） and IDWG% （r=0.269, P=0.013）. The incidence of inter- dialytic hypotension had no significant correlation with absolute sodium gradient and IDWG. Age was nega- tively correlated with predialysis serum sodium, absolute sodium gradient, IDWG and IDWG%. Conclusions The absolute sodium gradient was directly associated with IDWG, and higher absolute sodium gradient was associated with higher IDWG. Individualized sodium concentration in dialysate for each MHD patient may be useful for the prevention of overhydration in MHD patients.