Dialysate Sodium: Rationale for Evolution over Time

Oligo-anuric individuals receiving hemodialysis (HD) are dependent on the dialysis machine to regulate sodium and water balance. Interest in adjusting the dialysate sodium concentration to promote tolerance of the HD procedure dates back to the early years of dialysis therapy. Evolution of dialysis equipment technologies and clinical characteristics of the dialysis population have prompted clinicians to increase the dialysate sodium concentration over time. Higher dialysate sodium concentrations generally promote hemodynamic stabilization and reduce intradialytic symptoms but often do so at the expense of stimulating thirst and promoting volume expansion. The opposite may be true for lower dialysate sodium concentrations. Observational data suggest that the association between dialysate sodium and outcomes may differ by serum sodium levels, supporting the trend toward individualization of the dialysate sodium prescription. However, lack of randomized controlled clinical trial data, along with operational safety concerns related to individualized dialysate sodium prescriptions, have prevented expert consensus regarding the optimal approach to the dialysate sodium prescription

Shorter length dialysis sessions are associated with increased mortality, independent of body weight

Hemodialysis patients have high rates of mortality that may be related to aspects of the dialytic procedure. In prior studies, shorter length dialysis sessions have been associated with decreased survival, but these studies may have been confounded by body size differences. Here we tested whether in-center thrice-weekly hemodialysis patients with adequate urea clearances but shorter dialysis session length is associated with mortality independent of body size. Data were taken from a large national cohort of patients from a large dialysis organization undergoing thrice-weekly, in-center hemodialysis. In the primary analysis, patients with prescribed dialysis sessions greater and less than 240 minutes were pair-matched on post-dialysis weight as well as on age, gender, and vascular access type. Compared to prescribed longer dialysis sessions, session lengths less than 240 minutes were significantly associated with increased all-cause mortality (adjusted hazard ratio 1.26). The association was consistent across strata of age, gender, and dialysis post-weight. Secondary analyses found a dose-response between prescribed session length and survival. Thus, among patients with adequate urea clearance, shorter dialysis session lengths are associated with increased mortality independent of body weight

Ultrafiltration Rates and the Quality Incentive Program: Proposed Measure Definitions and Their Potential Dialysis Facility Implications

Rapid ultrafiltration rates are associated with adverse outcomes among patients on hemodialysis. The Centers for Medicare and Medicaid Services is considering an ultrafiltration rate quality measure for the ESRD Quality Incentive Program. Two measure developers proposed ultrafiltration rate measures with different selection criteria and specifications. We aimed to compare the proposed ultrafiltration rate measures and quantify dialysis facility operational burden if treatment times were extended to lower ultrafiltration rates

Ultrafiltration Rate and Mortality in Maintenance Hemodialysis Patients

Observational data have demonstrated an association between higher ultrafiltration (UF) rates and greater mortality among hemodialysis (HD) patients. Prior studies were small and did not consider potential differences in the association across body sizes and other related subgroups. No study has investigated UF rates normalized to anthropometric measures beyond body weight. Also, potential methodological shortcomings in prior studies have led to questions about the veracity of the UF rate–mortality association

Intradialytic Blood Pressure Abnormalities: The Highs, The Lows and All That Lies Between

Frequent blood pressure (BP) measurements are necessary to ensure patient safety during hemodialysis (HD) treatments. Intradialytic BPs are not optimal diagnostic tools for hypertension and cardiovascular risk stratification, but they do have critical clinical and prognostic significance. We present evidence associating intradialytic BP phenomena including fall, rise, and variability with adverse clinical outcomes and review related pathophysiologic mechanisms and potential management strategies

Rapid ultrafiltration rates and outcomes among hemodialysis patients: re-examining the evidence base

This review critically summarizes the evidence linking ultrafiltration (UF) rates to adverse outcomes among hemodialysis (HD) patients and provides research recommendations to address knowledge gaps

The Effect of Bicarbonate Administration via Continuous Venovenous Hemofiltration on Acid-Base Parameters in Ventilated Patients

Background. Acute kidney injury (AKI) and metabolic acidosis are common in the intensive care unit. The effect of bicarbonate administration on acid-base parameters is unclear in those receiving continuous venovenous hemofiltration (CVVH) and mechanical ventilatory support. Methods. Metabolic and ventilatory parameters were prospectively examined in 19 ventilated subjects for up to 96 hours following CVVH initiation for AKI at an academic tertiary care center. Mixed linear regression modeling was performed to measure changes in pH, partial pressure of carbon dioxide (pCO2), serum bicarbonate, and base excess over time. Results. During the 96-hour study period, pCO2 levels remained stable overall (initial pCO2 42.0 ± 14.6 versus end-study pCO2 43.8 ± 16.1 mmHg; P=0.13 for interaction with time), for those with initial pCO2 ≤40 mmHg (31.3 ± 5.7 versus 35.0 ± 4.8; P=0.06) and for those with initial pCO2 >40 mmHg (52.7 ± 12.8 versus 53.4 ± 19.2; P=0.57). pCO2 decreased during the immediate hours following CVVH initiation (42.0 ± 14.6 versus 37.3 ± 12.6 mmHg), though this change was nonsignificant (P=0.052). Conclusions. We did not detect a significant increase in pCO2 in response to the administration of bicarbonate via CVVH in a ventilated population. Additional studies of larger populations are needed to confirm this finding

Target weight achievement and ultrafiltration rate thresholds: potential patient implications

Abstract Background Higher ultrafiltration (UF) rates and extracellular hypo- and hypervolemia are associated with adverse outcomes among maintenance hemodialysis patients. The Centers for Medicare and Medicaid Services recently considered UF rate and target weight achievement measures for ESRD Quality Incentive Program inclusion. The dual measures were intended to promote balance between too aggressive and too conservative fluid removal. The National Quality Forum endorsed the UF rate measure but not the target weight measure. We examined the proposed target weight measure and quantified weight gains if UF rate thresholds were applied without treatment time (TT) extension or interdialytic weight gain (IDWG) reduction. Methods Data were taken from the 2012 database of a large dialysis organization. Analyses considered 152,196 United States hemodialysis patients. We described monthly patient and dialysis facility target weight achievement patterns and examined differences in patient characteristics across target weight achievement status and differences in facilities across target weight measure scores. We computed the cumulative, theoretical 1-month fluid-related weight gain that would occur if UF rates were capped at 13 mL/h/kg without concurrent TT extension or IDWG reduction. Results Target weight achievement patterns were stable over the year. Patients who did not achieve target weight (post-dialysis weight ≥ 1 kg above or below target weight) tended to be younger, black and dialyze via catheter, and had shorter dialysis vintage, greater body weight, higher UF rate and more missed treatments compared with patients who achieved target weight. Facilities had, on average, 27.1 ± 9.7% of patients with average post-dialysis weight ≥ 1 kg above or below the prescribed target weight. In adjusted analyses, facilities located in the midwest and south and facilities with higher proportions of black and Hispanic patients and higher proportions of patients with shorter TTs were more likely to have unfavorable facility target weight measure scores. Without TT extension or IDWG reduction, UF rate threshold (13 mL/h/kg) implementation led to an average theoretical 1-month, fluid-related weight gain of 1.4 ± 3.0 kg. Conclusions Target weight achievement patterns vary across clinical subgroups. Implementation of a maximum UF rate threshold without adequate attention to extracellular volume status may lead to fluid-related weight gain

Predictors of 30-Day Hospital Readmission among Maintenance Hemodialysis Patients: A Hospitals Perspective

Over 35% of patients on maintenance dialysis are readmitted to the hospital within 30 days of hospital discharge. Outpatient dialysis facilities often assume responsibility for readmission prevention. Hospital care and discharge practices may increase readmission risk. We undertook this study to elucidate risk factors identifiable from hospital-derived data for 30-day readmission among patients on hemodialysis