Peritoneal Dialysis Technique Survival: A Cohort Study.

RATIONALE & OBJECTIVE: Reasons for transfer from peritoneal dialysis (PD) to hemodialysis (HD) remain incompletely understood. Among incident and prevalent patients receiving PD, we evaluated the association of clinical factors, including prior treatment with HD, with PD technique survival. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adults who initiated PD at a Dialysis Clinic, Inc (DCI) outpatient facility between January 1, 2010, and September 30, 2019. EXPOSURE: The primary exposure of interest was timing of PD start, categorized as PD-first, PD-early, or PD-late. Other covariates included demographics, clinical characteristics, and routine laboratory results. OUTCOME: Modality switch from PD to HD sustained for more than 90 days. ANALYTICAL APPROACH: Multivariable Fine-Gray models with competing risks and time-varying covariates, stratified at 9 months to account for lack of proportionality. RESULTS: Among 5,224 patients who initiated PD at a DCI facility, 3,174 initiated dialysis with PD ("PD-first"), 942 transitioned from HD to PD within 90 days ("PD-early"), and 1,108 transitioned beyond 90 days ("PD-late"); 1,472 (28%) subsequently transferred from PD to HD. The PD-early and PD-late patients had a higher risk of transfer to HD as compared with PD-first patients (in the first 9 months: adjusted hazard ratio [AHR], 1.51 [95% CI, 1.17-1.96] and 2.41 [95% CI, 1.94-3.00], respectively; and after 9 months: AHR, 1.16 [95% CI, 0.99-1.35] and AHR, 1.43 [95% CI, 1.24-1.65], respectively). More peritonitis episodes, fewer home visits, lower serum albumin levels, lower residual kidney function, and lower peritoneal clearance calculated with weekly Kt/V were additional risk factors for PD-to-HD transfer. LIMITATIONS: Missing data on dialysis adequacy and residual kidney function, confounded by short PD technique survival. CONCLUSIONS: Initiating dialysis with PD is associated with greater PD technique survival, though many of those who initiate PD-late in their dialysis course still experience substantial time on PD. Peritonitis, lower serum albumin, and lower Kt/V are risk factors for PD-to-HD transfer that may be amenable to intervention. PLAIN-LANGUAGE SUMMARY: Peritoneal dialysis (PD) is an important kidney replacement modality with several potential advantages compared with in-center hemodialysis (HD). However, a substantial number of patients transfer to in-center HD early on, without having experienced the quality-of-life and other benefits that come with sustained maintenance of PD. Using retrospective data from a midsize national dialysis provider, we found that initiating dialysis with PD is associated with longer maintenance of PD, compared with initiating dialysis with HD and a later switch to PD. However, many of those who initiate PD-late in their dialysis course still experience substantial time on PD. Peritonitis, lower serum albumin, and lower small protein removal are other risk factors for PD-to-HD transfer that may be amenable to intervention.

Anemia management and association of race with mortality and hospitalization in a large not-for-profit dialysis organization.

BACKGROUND: The optimal hemoglobin target and possible toxicity of epoetin therapy in hemodialysis patients are controversial. Previous studies suggest that African American patients use higher doses of epoetin and have better survival compared with white hemodialysis patients. STUDY DESIGN: Retrospective longitudinal cohort. SETTING & PARTICIPANTS: Epoetin-exposed incident hemodialysis patients (N = 12,733; African Americans, n = 4,801; white, n = 7,386) treated in Dialysis Clinic Inc facilities during 2000 to 2006. PREDICTORS: Hemoglobin, epoetin, iron. OUTCOMES: Mortality, hospitalization. MEASUREMENTS: Proportional hazards models with time-varying covariates. RESULTS: Hemoglobin concentrations less than 10 g/dL in whites and less than 11 g/dL in African Americans were associated with increased mortality and hospitalization versus the referent hemoglobin level of 11 to 11.9 g/dL. Hemoglobin levels of 13 g/dL or greater in whites were associated with decreased noncardiovascular mortality. Six-month cumulative epoetin doses of 20,000 U/wk or greater were associated with increased mortality and hospitalization versus the referent group (8,000 to 12,499 U/wk). Epoetin doses less than 8,000 U/wk were associated with decreased risk. Higher epoetin doses were associated with increased mortality at hemoglobin concentrations of 10 to 12.9 g/dL and with increased hospitalization at all hemoglobin concentrations of 10 g/dL or greater. Higher epoetin doses were associated with increased mortality and hospitalization within each tertile of serum albumin concentration. These patterns did not differ by race. LIMITATIONS: Treatment-by-indication bias and unidentified confounders cannot be excluded. Small sample sizes in the highest and lowest hemoglobin strata decrease statistical power. CONCLUSIONS: Relationships between hemoglobin concentration and mortality differed between African Americans and whites. Additionally, the relationship of lower mortality with greater achieved hemoglobin concentration seen in white patients was observed for all-cause, but not cardiovascular, mortality. A higher cumulative epoetin dose was associated with worse outcomes, even in patients with albumin levels greater than 4 g/dL. There were no statistically significant interactions between race and epoetin dose. Further studies are needed to confirm and to define the mechanism of these findings.

Reducing versus discontinuing erythropoietin at high hemoglobin levels.

A 2006 change in Medicare policy allowed reimbursement for erythropoietin (EPO) in dialysis patients whose most recent hemoglobin exceeded 13 g/dl. We investigated the effects of a change in dosing algorithm implemented in response to this policy, in which EPO dosages were reduced instead of temporarily discontinued for hemoglobin levels > or =13 g/dl. Among 1688 individuals in 18 hemodialysis units, the reduction protocol resulted in more hemoglobin levels > or =13 g/dl (P < 0.0001), fewer levels between 11 and 12.9 g/dl (P < or = 0.004), no difference in the proportion of levels <11 g/dl, and more EPO administered per session (P < 0.0001) than the discontinuation protocol. In view of the expense of erythropoiesis stimulating agents and the uncertainty of the safety of using EPO to achieve high hemoglobin targets, this study suggests that discontinuation, rather than reduction, of EPO treatment is appropriate when hemoglobin reaches 13 g/dl in hemodialysis patients.

Which targets in clinical practice guidelines are associated with improved survival in a large dialysis organization?

Professional organizations have developed practice guidelines in the hope of improving clinical outcomes. The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has set targets for dialysis dosage (single-pool Kt/V), hematocrit, serum albumin, calcium, phosphorus, parathyroid hormone, and BP for hemodialysis (HD) patients. Several guidelines are largely based on results from observational studies. In contrast to other parameters, BP values within the KDOQI guidelines have been associated with increased mortality. Therefore, it was postulated that having multiple parameters that satisfy the current guidelines, except those for BP, is associated with improved survival among HD patients. A retrospective analysis was conducted of incident HD patients who were treated at facilities operated by Dialysis Clinic Inc., a not-for-profit dialysis provider, between January 1, 1998, and December 31, 2004 (n = 13,792). Cox proportional hazards models were used to assess the association between satisfying guidelines and mortality. Values within guidelines for single-pool Kt/V, hematocrit, serum albumin, calcium, phosphorus, and parathyroid hormone were associated with decreased mortality (P < or = 0.0001). The largest survival benefit was found for serum albumin (hazard ratio [HR] 0.27; 95% confidence interval [CI] 0.24 to 0.31). Satisfying these six guidelines simultaneously was associated with an 89% reduction in mortality (HR 0.11; 95% CI 0.06 to 0.19]). Conversely, BP values satisfying the guideline were associated with increased mortality (HR 1.90; 95% CI 1.73 to 2.10). Because this target was largely extrapolated from the general population, a randomized, controlled trial is needed to identify the optimal BP for HD patients.

Changing relationship of blood pressure with mortality over time among hemodialysis patients.

High BP is a major risk factor for atherosclerotic cardiovascular disease mortality in the general population. Surprising, studies that have been conducted among hemodialysis (HD) patients have yielded conflicting data on the relationship between BP and mortality. This study explores two hypotheses among HD patients: (1) The relationship between BP and mortality changes over time, and (2) mild to moderate hypertension is well tolerated. Incident HD patients who were treated at Dialysis Clinic Inc. facilities between 1993 and 2003 were studied. Primary end points were atherosclerotic cardiovascular disease and all-cause mortality. The relationship between BP and mortality was analyzed in two sets of Cox proportional hazards models. Model-B explored the relationship between baseline BP and mortality in sequential time periods. Model-TV assessed the relationship between BP, treated as time-varying, and mortality. The study sample (n = 16,959) was similar in characteristics to the United States Renal Data Systems population, although black patients were slightly overrepresented. Model-B demonstrated that the relationship between baseline BP and mortality changes over time. Low systolic BP (<120 mmHg) was associated with increased mortality in years 1 and 2. High systolic BP (> or =150 mmHg) was associated with increased mortality among patients who survived > or =3 yr. Low pulse pressure was associated with increased mortality. Model-TV demonstrated that mild to moderate systolic hypertension may be relatively well tolerated. In conclusion, the relationship between baseline BP and mortality changes over time. Mild to moderate systolic hypertension was associated with only modest increases in mortality.

The peritoneal dialysis experience: insights from long-term patients.

This exploratory-descriptive study identifies dimensions of self-management demonstrated by patients with end stage renal disease (ESRD) who have been successfully treated with peritoneal dialysis (PD) for more than 4 years (range = 4.1 to 13.1 years, mean = 7.5 years). After IRB review, semi-structured interviews were conducted with 18 individuals, 10 male and 8 female; 11 Caucasian, 6 African-American, and 1 Hispanic. Respondents ranged in age from 33 to 86 years (mean = 54.4 years). Interviews were audio-recorded and verbatim transcriptions were analyzed according to a content analytic procedure, with movement from specific to general. Two broad domains of self-management were identified: autonomy/control in health care and normality in everyday life. Autonomy/control was comprised of three specific dimensions: partnership in care, self-care, and self-care self-efficacy. Normality in everyday life included the dimensions of flexibility/freedom, interpretation of illness severity, and perception of body image. Although the small sample size and methodology limit generalizability, insights into the lived self-management experience on PD were identified. Such insights lay the groundwork for development of interventions to facilitate informed decision-making regarding dialysis modality, to teach tactics for effective self-management on PD, and to help health care professionals to support the self-management efforts of patients on PD.

Cardiac surgery after renal transplantation.

Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease has a high prevalence in this patient population. This study reviews the factors and outcomes associated with cardiac surgery in renal transplant recipients. We performed a retrospective review of all patients at our institution with a functioning renal allograft at the time of their cardiac surgical procedure. Between June 1971 and April 2000, 2343 patients underwent renal transplantation at Vanderbilt University Medical Center. Twenty-six patients with a functioning renal allograft subsequently underwent a cardiac procedure requiring cardiopulmonary bypass. There were 11 women and 15 men. Twenty-four patients underwent coronary bypass, one had a double valve replacement, and one had a combined coronary bypass/valve replacement. The interval from renal transplant to heart surgery ranged between 0.6 and 227 months (mean 79.1). Operative mortality was zero but there were two hospital deaths: one due to multisystem organ failure and one due to pulmonary embolism. Six additional patients died late with only one due to heart disease. Four patients required perioperative dialysis, and one of these went on to require permanent dialysis. Two additional patients returned to dialysis late postoperatively. The requirement for acute perioperative dialysis was predicted by preoperative creatinine, hematocrit, and intraoperative urine output. The overall survival is 69 per cent (18 of 26) with a median follow-up of 38 months. The majority of long-term survivors have minimal cardiac symptoms. Standard cardiac surgery procedures can be performed with relative safety in patients with functioning renal allografts. The incidence of perioperative and late development of renal failure requiring dialysis is low. The long-term survival and symptomatic improvement achieved are favorable and warrant continued performance of cardiac surgery in patients with functioning renal allografts.