BACKGROUND Stationary hemodialysis machines hinder mobility and limit activities of daily life during dialysis treatments. New hemodialysis technologies are needed to improve patient autonomy and enhance quality of life. METHODS We conducted a FDA-approved human trial of a wearable artificial kidney, a miniaturized, wearable hemodialysis machine, based on dialysate-regenerating sorbent technology. We aimed to determine the efficacy of the wearable artificial kidney in achieving solute, electrolyte, and volume homeostasis in up to 10 subjects over 24 hours. RESULTS During the study, all subjects remained hemodynamically stable, and there were no serious adverse events. Serum electrolytes and hemoglobin remained stable over the treatment period for all subjects. Fluid removal was consistent with prescribed ultrafiltration rates. Mean blood flow was 42 ± 24 ml/min, and mean dialysate flow was 43 ± 20 ml/min. Mean urea, creatinine, and phosphorus clearances over 24 hours were 17 ± 10, 16 ± 8, and 15 ± 9 ml/min, respectively. Mean β2-microglobulin clearance was 5 ± 4 ml/min. Of 7 enrolled subjects, 5 completed the planned 24 hours of study treatment. The trial was stopped after the seventh subject due to device-related technical problems, including excessive carbon dioxide bubbles in the dialysate circuit and variable blood and dialysate flows. CONCLUSION Treatment with the wearable artificial kidney was well tolerated and resulted in effective uremic solute clearance and maintenance of electrolyte and fluid homeostasis. These results serve as proof of concept that, after redesign to overcome observed technical problems, a wearable artificial kidney can be developed as a viable novel alternative dialysis technology. TRIAL REGISTRATION ClinicalTrials.gov NCT02280005. FUNDING The Wearable Artificial Kidney Foundation and Blood Purification Technologies Inc.

Patients prioritized the physical symptoms of insomnia, fatigue, and cramping and the mood symptoms of anxiety, depression, and frustration as the top symptoms for which to find new therapies.

Home dialysis, which comprises peritoneal dialysis (PD) or home hemodialysis (home HD), offers patients with ESRD greater flexibility and independence. Although ESRD disproportionately affects racial/ethnic minorities, data on disparities in use and outcomes with home dialysis are sparse. We analyzed data of patients who initiated maintenance dialysis between 2007 and 2011 and were admitted to any of 2217 dialysis facilities in 43 states operated by a single large dialysis organization, with follow-up through December 31, 2011 (n=162,050, of which 17,791 underwent PD and 2536 underwent home HD for $91 days). Every racial/ethnic minority group was significantly less likely to be treated with home dialysis than whites. Among individuals treated with in-center HD or PD, racial/ethnic minorities had a lower risk for death than whites; among individuals undergoing home HD, only blacks had a significantly lower death risk than whites. Blacks undergoing PD or home HD had a higher risk for transfer to in-center HD than their white counterparts, whereas Asians or others undergoing PD had a lower risk than whites undergoing PD. Blacks irrespective of dialysis modality, Hispanics undergoing PD or in-center HD, and Asians and other racial groups undergoing in-center HD were significantly less likely than white counterparts to receive a kidney transplant. In conclusion, there are racial/ethnic disparities in use of and outcomes with home dialysis in the United States. Disparities in kidney transplantation evident for blacks and Hispanics undergoing home dialysis are similar to those with in-center HD. Future studies should identify modifiable causes for these disparities.

Uncorrected serum calcium concentration is the first mineral metabolism metric planned for use as a quality measure in the United States ESRD population. Few studies in patients undergoing either peritoneal dialysis (PD) or hemodialysis (HD) have assessed the association of uncorrected serum calcium concentration with clinical outcomes. We obtained data from 129,076 patients on dialysis (PD, 10,066; HD, 119,010) treated in DaVita, Inc. facilities between July 1, 2001, and June 30, 2006. After adjustment for potential confounders, uncorrected serum calcium ,8.5 and $10.2 mg/dl were associated with excess mortality in patients on PD or HD (comparison group uncorrected calcium 9.0 to ,9.5 mg/dl). Additional adjustment for serum albumin concentration substantially attenuated the all-cause mortality hazard ratios (HRs) associated with uncorrected calcium ,8.5 mg/dl (HR, 1.29; 95% confidence interval [95% CI], 1.16 to 1.44 for PD; HR, 1.17; 95% CI, 1.13 to 1.20 for HD) and amplified the HRs associated with calcium $10.2 mg/dl (HR, 1.65; 95% CI, 1.42 to 1.91 for PD; HR, 1.59; 95% CI, 1.53 to 1.65 for HD). Albumin-corrected calcium $10.2 mg/dl and serum phosphorus $6.4 mg/dl were also associated with increased risk for death, irrespective of dialysis modality. In summary, in a large nationally representative cohort of patients on dialysis, abnormalities in markers of mineral metabolism, particularly high concentrations of serum calcium and phosphorus, were associated with increased mortality risk. Additional studies are needed to investigate whether control of hypercalcemia and hyperphosphatemia in patients undergoing dialysis results in improved clinical outcomes.

Individuals receiving in-center maintenance hemodialysis bear a high burden of both physical and mood symptoms. More than half of patients on hemodialysis report sleep disturbance, muscle cramps, and fatigue. Patients describe symptoms as having a deleterious effect on their quality of life, suggesting that symptom alleviation may meaningfully improve patient-reported outcomes. Moreover, patients on hemodialysis have identified symptom management as a key area for research and innovation, prioritizing symptom alleviation over other health outcomes such as mortality and biochemical indices. Despite the importance of symptoms to patients, there has been little research explicitly geared toward improving patient symptoms, and therefore minimal innovation in symptom management. In general, the physiologic underpinnings of symptoms are poorly understood, hampering the development of targeted therapies. In fact, there have been few drugs or devices approved by the US Food and Drug Administration for the indication of improving any patient-reported outcomes for patients on hemodialysis. Recognizing this gap in innovation, the Kidney Health Initiative, a public-private partnership between the American Society of Nephrology and US Food and Drug Administration, convened a workgroup to first prioritize symptoms for the development of therapeutic interventions, and then identify near-term actionable research goals for the prioritized physical symptoms of insomnia, muscle cramps, and fatigue. This paper summarizes the pathophysiology of the three prioritized symptoms, identifies key knowledge gaps, acknowledges factors that challenge development of new therapies, and offers the nephrology community actionable research goals for insomnia, muscle cramps, and fatigue.