Association of Ultrafiltration Rate with Mortality in Incident Hemodialysis Patients

Abstract

Background/Aims: Ultrafiltration rate (UFR) appears to be associated with mortality in prevalent hemodialysis (HD) patients. However, the association of UFR with mortality in incident HD patients remains unknown. Methods: We examined a US cohort of 110,880 patients who initiated HD from 2007 to 2011. Baseline UFR was divided into 5 groups (<4, 4 to <6, 6 to <8, 8 to <10, and ≥10 mL/h/kg body weight [BW]). We examined predictors of higher baseline UFR using logistic regression and the association of baseline UFR and all-cause and cardiovascular (CV) mortality using Cox proportional hazard models with adjustments for demographics, comorbidities, and markers of malnutrition-inflammation-cachexia syndrome. Results: Patients were 63 ± 15 years, with 43% women, 32% African Americans, and had a mean baseline UFR of 7.5 ± 3.1 mL/h/kg BW. In the fully adjusted logistic regression models, factors associated with higher UFR (≥7.5 mL/h/kg BW) included Hispanic ethnicity, diabetes, and higher dietary protein intake. There was a linear association between UFR and all-cause and CV mortality, where UFR ≥10 mL/h/kg BW (reference UFR 6–<8 mL/h/kg BW) conferred the highest risk in both unadjusted (HR 1.15 [95% CI 1.10–1.19]) and adjusted models (HR 1.23 [95% CI 1.16–1.31]). The linear association with all-cause mortality remained consistent across strata of age, urine volume, and treatment time. Conclusions: Higher UFR is independently associated with higher all-cause and CV mortality in incident HD patients. Clinical trials are warranted to examine the effects of lowering UFR on outcomes.

Association of Net Ultrafiltration Rate With Mortality Among Critically Ill Adults With Acute Kidney Injury Receiving Continuous Venovenous Hemodiafiltration

“…Among critically ill patients receiving CVVHDF, we found that an NUF rate greater than 1.75 mL/kg/h compared with an NUF rate less than 1.01 mL/kg/h was associated with lower risk-adjusted 90-day survival between day 7 and day 90. These findings are aligned with several recent studies in outpatients with end-stage renal disease 10 , 11 , 12 , 13 that found that higher NUF rates are associated with decreased survival.…”

“…In contrast, emerging evidence from outpatients with end-stage renal disease receiving hemodialysis suggests that an NUF rate greater than 13 mL/kg/h per session compared with an NUF rate of 10 mL/kg/h or less is associated with mortality. 10 , 11 , 12 , 13 However, the implications and generalizability of these study findings to patients undergoing continuous NUF are unclear.…”

Recovery Time after Hemodialysis Is Inversely Associated with the Ultrafiltration Rate

“…It remains to be investigated whether the reduction of recovery time may be obtained with the increase of the UFR in the routine clinical practice and whether this is appropriate. In fact, it is well known that a higher UFR has been associated with increased mortality [19][20][21] and with hemodynamic effects such as reduced myocardial blood and myocardial stunning [22][23][24]. Nevertheless, an ideal UFR has not yet been identified [25].…”

Association between Ultrafiltration Rate and Clinical Outcome Is Modified by Muscle Mass in Hemodialysis Patients

“…Various risk factors for worse survival rates have been reported [3][4][5][6][7][8][9]. High ultrafiltration rate (UFR), that is, rapid fluid removal, is recognized as one of the risk factors responsible for these poor outcomes [10][11][12][13][14]. High UFR could increase the development of intradialytic hypotension (IDH), which might be associated with end-organ ischemia of the heart, brain, DOI: 10.1159/000509350 and gut, and this may consequently lead to increased mortality risk [15][16][17][18].…”