The relationship between prescription of ultrafiltration and intradialytic hypotension in Chinese hemodialysis patients

Background: Intradialytic hypotension (IDH) remains the most frequent severe side effect of hemodialysis (HD) and increases patient morbidity and mortality. Excessive ultrafiltration (UF) is considered the leading cause of IDH. This study developed a suitable prescription of UF to reduce the incidences of IDH episodes. Methods: A retrospective study was performed to analyze 33,224 HD/hemodiafiltration (HDF) treatments in 312 patients. The prescription of UF were determined following the International Society of Peritoneal Dialysis ( ISPD) guideline. The Pearson's method was used to study the correlation between relative variables. The receiver operating characteristic (ROC) curve was used to predict the value of the UF/weight ratio (UF/Wt) for IDH in all patients to establish a diagnostic cut- off point. Univariate and multivariate logistic regression analyses were applied to study the risk factors of IDH. Results: Twelve thousand five hundred and fifty-eight sessions of IDH (38.7%) were identified, among which 1,224 (3.6%) were recorded with intervention against IDH. Both the systolic blood pressure (SBP) and mean arterial pressure (MAP) of the hemodialytic patients were positively correlated with the UF quantity and the UF/Wt, but negatively correlated with blood flow. The ROC curve showed that UF/Wt =0.04 was the cut-off point for IDH. Age [per 10-year increment, odds ratio (OR) =1.005, 95% confidence interval (CI): 1.004 to 1.007, P=0.000], diabetes mellitus (OR =1.209, 95% CI: 1.122 to 1.303, P=0.000), and UF/Wt >0.04 (OR =1.605, 95% CI: 1.532 to 1.682, P=0.000) were all independently associated with higher incidences of IDH. Conclusions: IDH commonly occurs during HD in Chinese patients. Unchangeable factors such as diabetes and age, and modifiable factors including UF were associated with IDH. A UF/Wt threshold more than 0.04 may be a potential alert for avoiding IDH, especially in the elderly and diabetic patients.