Machine Learning Case Study: Patterns of Kidney Function Decline and Their Association With Clinical Outcomes Within 90 Days After the Initiation of Renal Dialysis.

A case study explores patterns of kidney function decline using unsupervised learning methods first and then associating patterns with clinical outcomes using supervised learning methods. Predicting short-term risk of hospitalization and death prior to renal dialysis initiation may help target high-risk patients for more aggressive management. This study combined clinical data from patients presenting for renal dialysis at Fresenius Medical Care with laboratory data from Quest Diagnostics to identify disease trajectory patterns associated with the 90-day risk of hospitalization and death after beginning renal dialysis. Patients were clustered into 4 groups with varying rates of estimated glomerular filtration rate (eGFR) decline during the 2-year period prior to dialysis. Overall rates of hospitalization and death were 24.9% (582/2341) and 4.6% (108/2341), respectively. Groups with the steepest declines had the highest rates of hospitalization and death within 90 days of dialysis initiation. The rate of eGFR decline is a valuable and readily available tool to stratify short-term (90 days) risk of hospitalization and death after the initiation of renal dialysis. More intense approaches are needed that apply models that identify high risks to potentially avert or reduce short-term hospitalization and death of patients with a severe and rapidly progressive chronic kidney disease.

Assessing the impact of transitional care units on dialysis patient outcomes: A multicenter, propensity score-matched analysis.

INTRODUCTION: Inadequate predialysis care and education impacts the selection of a dialysis modality and is associated with adverse clinical outcomes. Transitional care units (TCUs) aim to meet the unmet educational needs of incident dialysis patients, but their impact beyond increasing home dialysis utilization has been incompletely characterized. METHODS: This retrospective study included adults initiating in-center hemodialysis at a TCU, matched to controls (1:4) with no TCU history initiating in-center hemodialysis. Patients were followed for up to 14 months. TCUs are dedicated spaces where staff provide personalized education and as-needed adjustments to dialysis prescriptions. For many patients, therapy was initiated with four to five weekly dialysis sessions, with at least some sessions delivered by home dialysis machines. Outcomes included survival, first hospitalization, transplant waiting-list status, post-TCU dialysis modality, and vascular access type. FINDINGS: The study included 724 patients initiating dialysis across 48 TCUs, with 2892 well-matched controls. At the end of 14 months, patients initiating dialysis in a TCU were significantly more likely to be referred and/or wait-listed for a kidney transplant than controls (57% vs. 42%; p < 0.0001). Initiation of dialysis at a TCU was also associated with significantly lower rates of receiving in-center hemodialysis at 14 months (74% vs. 90%; p < 0.0001) and higher rates of arteriovenous access (70% vs. 63%; p = 0.003). Although not statistically significant, TCU patients were more likely to survive and less likely to be hospitalized during follow-up than controls. DISCUSSION: Although TCUs are sometimes viewed as only a means for enhancing utilization of home dialysis, patients attending TCUs exhibited more favorable outcomes across all endpoints. In addition to being 2.5-fold more likely to receive home dialysis, TCU patients were 42% more likely to be referred for transplantation. Our results support expanding utilization of TCUs for patients with inadequate predialysis support.

Predictors of shorter- and longer-term mortality after COVID-19 presentation among dialysis patients: parallel use of machine learning models in Latin and North American countries.

BACKGROUND: We developed machine learning models to understand the predictors of shorter-, intermediate-, and longer-term mortality among hemodialysis (HD) patients affected by COVID-19 in four countries in the Americas. METHODS: We used data from adult HD patients treated at regional institutions of a global provider in Latin America (LatAm) and North America who contracted COVID-19 in 2020 before SARS-CoV-2 vaccines were available. Using 93 commonly captured variables, we developed machine learning models that predicted the likelihood of death overall, as well as during 0-14, 15-30, > 30 days after COVID-19 presentation and identified the importance of predictors. XGBoost models were built in parallel using the same programming with a 60%:20%:20% random split for training, validation, & testing data for the datasets from LatAm (Argentina, Columbia, Ecuador) and North America (United States) countries. RESULTS: Among HD patients with COVID-19, 28.8% (1,001/3,473) died in LatAm and 20.5% (4,426/21,624) died in North America. Mortality occurred earlier in LatAm versus North America; 15.0% and 7.3% of patients died within 0-14 days, 7.9% and 4.6% of patients died within 15-30 days, and 5.9% and 8.6% of patients died > 30 days after COVID-19 presentation, respectively. Area under curve ranged from 0.73 to 0.83 across prediction models in both regions. Top predictors of death after COVID-19 consistently included older age, longer vintage, markers of poor nutrition and more inflammation in both regions at all timepoints. Unique patient attributes (higher BMI, male sex) were top predictors of mortality during 0-14 and 15-30 days after COVID-19, yet not mortality > 30 days after presentation. CONCLUSIONS: Findings showed distinct profiles of mortality in COVID-19 in LatAm and North America throughout 2020. Mortality rate was higher within 0-14 and 15-30 days after COVID-19 in LatAm, while mortality rate was higher in North America > 30 days after presentation. Nonetheless, a remarkable proportion of HD patients died > 30 days after COVID-19 presentation in both regions. We were able to develop a series of suitable prognostic prediction models and establish the top predictors of death in COVID-19 during shorter-, intermediate-, and longer-term follow up periods.

Choices in hemodialysis therapies: variants, personalized therapy and application of evidence-based medicine.

The extent of removal of the uremic toxins in hemodialysis (HD) therapies depends primarily on the dialysis membrane characteristics and the solute transport mechanisms involved. While designation of 'flux' of membranes as well toxicity of compounds that need to be targeted for removal remain unresolved issues, the relative role, efficiency and utilization of solute removal principles to optimize HD treatment are better delineated. Through the combination and intensity of diffusive and convective removal forces, levels of concentrations of a broad spectrum of uremic toxins can be lowered significantly and successfully. Extended clinical experience as well as data from several clinical trials attest to the benefits of convection-based HD treatment modalities. However, the mode of delivery of HD can further enhance the effectiveness of therapies. Other than treatment time, frequency and location that offer clinical benefits and increase patient well-being, treatment- and patient-specific criteria may be tailored for the therapy delivered: electrolytic composition, dialysate buffer and concentration and choice of anticoagulating agent are crucial for dialysis tolerance and efficacy. Evidence-based medicine (EBM) relies on three tenets, i.e. clinical expertise (i.e. doctor), patient-centered values (i.e. patient) and relevant scientific evidence (i.e. science), that have deviated from their initial aim and summarized to scientific evidence, leading to tyranny of randomized controlled trials. One must recognize that practice patterns as shown by Dialysis Outcomes and Practice Patterns Study and personalization of HD care are the main driving force for improving outcomes. Based on a combination of the three pillars of EBM, and particularly on bedside patient-clinician interaction, we summarize what we have learned over the last 6 decades in terms of best practices to improve outcomes in HD patients. Management of initiation of dialysis, vascular access, preservation of kidney function, selection of biocompatible dialysers and use of dialysis fluids of high microbiological purity to restrict inflammation are just some of the approaches where clinical experience is vital in the absence of definitive scientific evidence. Further, HD adequacy needs to be considered as a broad and multitarget approach covering not just the dose of dialysis provided, but meeting individual patient needs (e.g. fluid volume, acid-base, blood pressure, bone disease metabolism control) through regular assessment-and adjustment-of a series of indicators of treatment efficiency. Finally, in whichever way new technologies (i.e. artificial intelligence, connected health) are embraced in the future to improve the delivery of dialysis, the human dimension of the patient-doctor interaction is irreplaceable. Kidney medicine should remain 'an art' and will never be just 'a science'.

Optimizing serum total carbon dioxide concentration during short and nocturnal frequent hemodialysis using lactate as dialysate buffer base.

INTRODUCTION: Definitive clinical studies to determine the optimal dialysate lactate concentration to prescribe during frequent hemodialysis when using the NxStage System One dialysis delivery system at low dialysate flow rates have not been reported. METHODS: We used clinical data from patients who transferred from in-center thrice-weekly hemodialysis (ICHD) to daily home hemodialysis using the NxStage System One and the H+ mobilization model to calculate acid generation rates in patient sub-groups during the FREEDOM study. Assuming those acid generation rates were representative, we then predicted using the H+ mobilization model the effect of using dialysate lactate concentrations of 40 and 45 mEq/L on predialysis serum total carbon dioxide (tCO2 ) concentrations in patients who transfer from ICHD to short and nocturnal frequent hemodialysis prescriptions used in current clinical practice; the prescriptions evaluated varied by treatment frequency, dialysate volume per treatment, and treatment times. FINDINGS: With frequencies of four to six treatments per week and treatment times of 170 to 210 minutes per treatment, the effect of dialysate lactate concentration was primarily dependent on weekly dialysate volume. For weekly dialysate volumes of 150 to 160 L per week, use of dialysate lactate concentrations of 45 mEq/L, but not 40 mEq/L, resulted in an increase of predialysis serum tCO2 concentration. When longer treatment times typical of nocturnal frequent hemodialysis were evaluated, model predictions showed that the use of dialysate lactate concentration of 45 mEq/L may not be appropriate for many patients because of excessive increases in predialysis serum tCO2 concentration. Reducing dialysate volume from 60 to 30 L may limit the increase in predialysis serum tCO2 concentration when patients transfer from ICHD to nocturnal frequent hemodialysis. DISCUSSION: Predictions from the H+ mobilization model show that dialysate lactate concentration and weekly dialysate volume are the primary prescription parameters for optimizing predialysis serum tCO2 concentration during short and nocturnal frequent hemodialysis.

Acid-base kinetics during hemodialysis using bicarbonate and lactate as dialysate buffer bases based on the H+ mobilization model.

BACKGROUND: The H+ mobilization model has been recently reported to accurately describe intradialytic kinetics of plasma bicarbonate concentration; however, the ability of this model to predict changing bicarbonate kinetics after altering the hemodialysis treatment prescription is unclear. METHODS: We considered the H+ mobilization model as a pseudo-one-compartment model and showed theoretically that it can be used to determine the acid generation (or production) rate for hemodialysis patients at steady state. It was then demonstrated how changes in predialytic, intradialytic, and immediate postdialytic plasma bicarbonate (or total carbon dioxide) concentrations can be calculated after altering the hemodialysis treatment prescription. RESULTS: Example calculations showed that the H+ mobilization model when considered as a pseudo-one-compartment model predicted increases or decreases in plasma total carbon dioxide concentrations throughout the entire treatment when the dialysate bicarbonate concentration is increased or decreased, respectively, during conventional thrice weekly hemodialysis treatments. It was further shown that this model allowed prediction of the change in plasma total carbon dioxide concentration after transfer of patients from conventional thrice weekly to daily hemodialysis using both bicarbonate and lactate as dialysate buffer bases. CONCLUSION: The H+ mobilization model can predict changes in plasma bicarbonate or total carbon dioxide concentration during hemodialysis after altering the hemodialysis treatment prescription.

Effect of dialysate potassium and lactate on serum potassium and bicarbonate concentrations during daily hemodialysis at low dialysate flow rates.

BACKGROUND: Observational studies of hemodialysis patients treated thrice weekly have shown that serum and dialysate potassium and bicarbonate concentrations are associated with patient outcomes. The effect of more frequent hemodialysis on serum potassium and bicarbonate concentrations has rarely been studied, especially for treatments at low dialysate flow rate. METHODS: These post-hoc analyses evaluated data from patients who transferred from in-center hemodialysis (HD) to daily HD at low dialysate flow rates during the FREEDOM Study. The primary outcomes were the change in predialysis serum potassium and bicarbonate concentrations after transfer from in-center HD (mean during the last 3 months) to daily HD (mean during the first 3 months). RESULTS: After transfer from in-center HD to daily HD (data from 345 patients, 51 ± 15 years of age, mean ± standard deviation), predialysis serum potassium decreased (P < 0.001) by approximately 0.4 mEq/L when dialysate potassium concentration during daily HD was 1 mEq/L; no change occurred when dialysate potassium concentration during daily HD was 2 mEq/L. After transfer from in-center HD to daily HD (data from 284 patients, 51 ± 15 years of age), predialysis serum bicarbonate concentration decreased (P = 0.0022) by 1.0 ± 3.3 mEq/L when dialysate lactate concentration was 40 mEq/L but increased (P < 0.001) by 2.5 ± 3.5 mEq/L when dialysate lactate concentration was 45 mEq/L. These relationships were dependent on serum potassium and bicarbonate concentrations during in-center HD. CONCLUSIONS: Control of serum potassium and bicarbonate concentrations during daily HD at low dialysate flow rates is readily achievable; the choice of dialysate potassium and lactate concentration can be informed when transfer is from in-center HD to daily HD.

Intensive Hemodialysis, Blood Pressure, and Antihypertensive Medication Use.

Hypertension is a cardinal feature of end-stage renal disease (ESRD). Hypertensive nephropathy is the primary cause of ESRD for nearly 30% of patients, and the prevalence of hypertension is >85% in new patients with ESRD. In contemporary hemodialysis (HD) patients, mean predialysis systolic blood pressure (SBP) is nearly 150mmHg, and about 70%, 50%, and 40% use ß-blockers, calcium channel blockers, and renin-angiotensin system inhibitors, respectively. Predialysis SBP generally exhibits a U-shaped association with mortality risk. Interdialytic ambulatory SBP is more strongly associated with risk. Hypertension is multifactorial; key causes include persistent hypervolemia and elevated peripheral resistance. With 3 HD sessions per week, blood pressure (BP) climbs during the interdialytic interval, in step with interdialytic weight gain, particularly among elderly patients and those with higher dry weight. Elevated peripheral resistance can be attributed to inappropriate activation of the sympathetic nervous system due to higher plasma norepinephrine concentrations. Multiple randomized clinical trials show that intensive HD reduces BP and the need for oral medications indicated for hypertension. In the first 2 months of the Frequent Hemodialysis Network trial, the short daily schedule reduced predialysis SBP by 7.7mmHg, whereas the nocturnal schedule reduced predialysis SBP by 7.3mmHg, both relative to 3 sessions per week. Improvements were sustained after 12 months. Both schedules reduced antihypertensive medication use relative to 3 sessions per week. In FREEDOM (Following Rehabilitation, Economics, and Everyday-Dialysis Outcome Measurements), a prospective cohort study of short daily HD, the mean number of prescribed antihypertensive agents decreased from 1.7 to 1.0 in 1 year, whereas the percentage of patients not prescribed antihypertensive agents increased from 21% to 47%. Nocturnal HD appears to markedly reduce total peripheral resistance and plasma norepinephrine and restore endothelium-dependent vasodilation. In conclusion, intensive HD reduces BP and the need for antihypertensive medications.

Intensive Hemodialysis and Health-Related Quality of Life.

Diminished health-related quality of life (HRQoL) is common in dialysis patients and associated with increased risks for morbidity and mortality. Patients may present limitations in both physical and mental HRQoL. Poor physical HRQoL may be defined by limited physical function, role limitations due to physical health, dissatisfaction with physical ability, and impaired mobility. Sleep disorders such as obstructive sleep apnea, restless legs, and fatigue are typical manifestations of poor physical HRQoL in dialysis patients. Poor mental HRQoL may be defined by depressive thinking, lack of positive affect, anxiety, and feelings of social isolation. The prevalence of depression is high in dialysis patients. Intensive hemodialysis (HD) can positively address HRQoL. In 3 randomized clinical trials, relative to conventional HD, intensive HD increased physical and mental component summary scores from the 36-Item Short-Form Health Survey (SF-36), although individual treatment effects of daily nocturnal HD were not statistically significant. In another large prospective study, initiation of short daily HD therapy was followed after 12 months by improvements in all SF-36 domains, sleep quality, and restless legs symptoms. In a small study of nocturnal HD, apnea and hypopnea episodes per hour decreased by almost 70% after conversion from conventional HD. Intensive HD is also associated with a large reduction in postdialysis recovery time. In contrast, 2 randomized clinical trials failed to demonstrate statistically significant effects of intensive HD on the Beck Depression Inventory score despite a significant decrease in Beck Depression Inventory score in the prospective study of short daily HD. Furthermore, intensive HD may not improve objective physical performance and can increase burden on caregivers in the home setting. In conclusion, intensive HD potentially can address both physical and mental aspects of poor HRQoL relative to conventional HD. However, more studies are needed to understand the effects of intensive HD, including specific schedules, on HRQoL.

Intensive Hemodialysis and Potential Risks With Increasing Treatment.

Although intensive hemodialysis (HD) can address important clinical problems, increasing treatment also introduces risks. In this review, we assess risks pertaining to 6 domains: vascular access complications, infection, mortality, loss of residual kidney function, solute balance, and patient and care partner burden. In the Frequent Hemodialysis Network (FHN) trials, short daily and nocturnal schedules increased the incidence of access complications, although the incidence of access loss was not statistically higher. Observational studies indicate that infection-related hospitalization is an ongoing challenge with short daily HD. Excess risk may be catalyzed by poor infection control practices in the home setting in which intensive HD is typically delivered, but with fixed probability of bacterial contamination per cannulation, greater treatment frequency necessarily increases the risk for infectious complications. Buttonhole cannulation may increase the risk for metastatic infections. However, intensive HD in the home setting is associated with lower risk for infection than peritoneal dialysis. Data regarding mortality are equivocal. With extended follow-up of individuals in the FHN trials, short daily HD was associated with lower risk relative to the usual schedule, whereas nocturnal HD was associated with higher risk. In many, but not all, observational studies, short daily HD has been associated with lower risk than both in-center HD and peritoneal dialysis; however, observational studies are subject to unmeasured confounding. Intensive HD can accelerate the loss of residual kidney function in new dialysis patients with substantial urine output and can deplete solutes (eg, phosphorus) to the extent that supplementation is necessary. Finally, intensive HD may increase burden on patients and caregivers, possibly leading to technique failure. Some of these problems might be addressed with careful monitoring, so that relevant interventions (eg, antibiotics, retraining, and respite care) can be delivered. Ultimately, intensive HD is not a panacea for end-stage renal disease. Potential benefits and risks of treatment should be jointly considered.

Laparoscopic Renal Denervation for Uncontrolled Hypertension Due to Medication Intolerance: A Case Report.

Resistant hypertension is challenging to treat, and most patients with the condition fail to achieve blood pressure control, putting them at increased risk for adverse long-term outcomes. We present the case of a 59-year-old woman with resistant hypertension due to intolerance to nearly all antihypertensive medications. After failure to achieve blood pressure control over a 5-year period, with blood pressures as high as 220/110mmHg, the patient underwent surgical treatment with bilateral laparoscopic renal denervation. Immediately after the procedure, as well as at the 1-, 3-, 9-, and 12-month follow-ups, the patient's blood pressure was reduced to the range of 120-140/80-90mmHg.

Gentamicin pharmacokinetics and pharmacodynamics during short-daily hemodialysis.

BACKGROUND/AIMS: Gentamicin pharmacokinetics have not been described in patients undergoing short-daily hemodialysis (SDHD). The aim of this study is to describe gentamicin pharmacokinetics and dialytic clearance (Cl(dial)) in SDHD patients and simulate gentamicin exposure after six dosing regimens to help guide future dosing. METHODS: Six anuric patients undergoing SDHD were enrolled. Patients received intravenous infusion of 2 mg/kg gentamicin on day 1 after the first HD session followed by HD sessions on days 2, 3, and 4. Blood samples for determination of gentamicin concentrations were serially collected. Gentamicin pharmacokinetic parameters and Cl(dial) and interindividual variability terms (IIV) were estimated using NONMEM VII. Influence of patient weight on systemic clearance (Cl(s)) and central volume of distribution (V(c)) and influence of urea removal estimates on Cl(dial) were assessed. The model was used to simulate gentamicin concentrations after six dosing regimens including pre- and postdialysis as well as daily and every-other-day dosing. RESULTS: A two-compartment model with first-order elimination from central compartment described gentamicin pharmacokinetics. Population estimates for Cl(s) and Cl(dial) were 7.6 and 134 ml/min, respectively. Patient weight was statistically significantly associated with Cl(s) and V(c). Predialysis every-other-day regimens were as effective (C(max) ≥8 mg/l and AUC(48 h) ≥140 mg·h/l) and less toxic (C(min) <2 mg/l and AUC(48 h) <240 mg·h/l) than postdialysis regimens. CONCLUSIONS: Estimated gentamicin Cl(dial) is higher than previous estimates with thrice-weekly regimens. Predialysis every-other-day dosing may be recommended during SDHD.

At-home short daily hemodialysis improves the long-term health-related quality of life.

Patients with chronic kidney disease treated by in-center conventional hemodialysis (3 times per week) have significant impairments in health-related quality of life measures, which have been associated with increased morbidity and mortality. FREEDOM is an ongoing prospective cohort study measuring the potential benefits of at-home short daily (6 times per week) hemodialysis. In this interim report we examine the long-term effect of short daily hemodialysis on health-related quality of life, as measured by the SF-36 health survey. This was administered at baseline, 4 and 12 months after initiation of short daily hemodialysis to 291 participants (total cohort), of which 154 completed the 12-month follow-up (as-treated cohort). At the time of analysis, the mean age was 53 years, 66% were men, 58% had an AV fistula, 90% transitioned from in-center hemodialysis, and 45% had diabetes mellitus. In the total cohort analysis, both the physical- and mental-component summary scores improved over the 12-month period, as did all 8 individual domains of the SF-36. The as-treated cohort analysis showed similar improvements with the exception of the role-emotional domain. Significantly, in the as-treated cohort, the percentage of patients achieving a physical-component summary score at least equivalent to the general population more than doubled. Hence, at-home short daily hemodialysis is associated with long-term improvements in various physical and mental health-related quality of life measures.

Impact of short daily hemodialysis on restless legs symptoms and sleep disturbances.

BACKGROUND AND OBJECTIVES: Restless legs syndrome (RLS) and sleep disturbances are common among in-center hemodialysis patients and are associated with increased morbidity/mortality. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The FREEDOM study is an ongoing prospective cohort study investigating the benefits of home short daily hemodialysis (SDHD) (6 times/week). In this interim report, we examine the long-term effect of SDHD on the prevalence and severity of RLS, as measured by the International Restless Legs Syndrome (IRLS) Study Group rating scale, and sleep disturbances, as measured by the Medical Outcomes Study sleep survey. RESULTS: 235 participants were included in this report (intention-to-treat cohort), of which 127 completed the 12-month follow-up (per-protocol cohort). Mean age was 52 years, 55% had an arteriovenous fistula, and 40% suffered from RLS. In the per-protocol analysis, among patients with RLS, the mean IRLS score improved significantly at month 12, after adjustment for use of RLS-related medications (18 versus 11). Among patients with moderate-to-severe RLS (IRLS score ≥15), there was an even greater improvement in the IRLS score (23 versus 13). The intention-to-treat analysis yielded similar results. Over 12 months, there was decline in the percentage of patients reporting RLS (35% versus 26%) and those reporting moderate-to-severe RLS (59% versus 43%). There was a similar and sustained 12-month improvement in several scales of the sleep survey, after adjustment for presence of RLS and use of anxiolytics and hypnotics. CONCLUSIONS: Home SDHD is associated with long-term improvement in the prevalence and severity of RLS and sleep disturbances.

Effect of daily hemodialysis on depressive symptoms and postdialysis recovery time: interim report from the FREEDOM (Following Rehabilitation, Economics and Everyday-Dialysis Outcome Measurements) Study.

BACKGROUND: Clinical depression and postdialysis fatigue are important concerns for patients with kidney failure and can have a negative impact on quality of life and survival. STUDY DESIGN: The FREEDOM (Following Rehabilitation, Economics and Everyday-Dialysis Outcome Measurements) Study is an ongoing prospective cohort study investigating the clinical and economic benefits of daily (6 times per week) hemodialysis (HD). In this interim report, as part of an a priori planned analysis, we examine the long-term impact of daily HD on depressive symptoms, measured using the Beck Depression Inventory (BDI) survey, and postdialysis recovery time, measured using a previously validated questionnaire. SETTING & PARTICIPANTS: Adult patients initiating daily HD with a planned 12-month follow-up. OUTCOMES & MEASUREMENTS: The BDI survey and postdialysis recovery time question were administered at baseline, and changes were assessed at months 4 and 12. RESULTS: 239 participants were enrolled (intention-to-treat cohort) and 128 completed the study (per-protocol cohort). Mean age was 52 years, 64% were men, 55% had an arteriovenous fistula, and 90% transitioned from in-center HD therapy. In the per-protocol cohort, there was a significant decrease in mean BDI score over 12 months (11.2 [95% CI, 9.6-12.9] vs 7.8 [95% CI, 6.5-9.1]; P<0.001). For robustness, the intention-to-treat analysis was performed, yielding similar results. The percentage of patients with depressive symptoms (BDI score>10) significantly decreased during 12 months (41% vs 27%; P=0.03). Similarly, in the per-protocol cohort, there was a significant decrease in postdialysis recovery time over 12 months (476 [95% CI, 359-594] vs 63 minutes [95% CI, 32-95]; P<0.001). The intention-to-treat analysis yielded similar results. The percentage of patients experiencing prolonged postdialysis recovery time (>or=60 minutes) also significantly decreased (81% vs 35%; P=0.001). LIMITATIONS: Observational study with lack of control arm. CONCLUSIONS: Daily HD is associated with long-term improvement in depressive symptoms and postdialysis recovery time.

Vancomycin pharmacokinetics and pharmacodynamics during short daily hemodialysis.

BACKGROUND AND OBJECTIVES: Short daily hemodialysis (SDHD) is an alternative to thrice-weekly HD because of its putative physiologic benefits. The purpose of this study was to investigate the effect of SDHD on the pharmacokinetics and pharmacodynamics of vancomycin. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Six noninfected adults who had anuria and were treated with SDHD were studied and received four dialysis sessions over 4 days. After completion of the first SDHD, each patient received vancomycin 15 mg/kg by intravenous infusion. Blood samples were collected over the ensuing 3 days during each subsequent inter- and intradialytic period. Pharmacokinetic parameters were determined. Serum concentration-time profiles were simulated for four vancomycin regimens with maintenance doses administered after every other SDHD. Area under the serum-concentration time curve (AUC) from 0 to 48 hours, 48 to 96 hours, and 96 to 144 hours were calculated, and Monte Carlo simulations were performed to determine the probability of target attainment at an AUC/minimum inhibitory concentration (MIC) ratio ≥800 for each 48-hour AUC at MICs ranging from 0.5 to 2.0 µg/ml. RESULTS: Median (range) systemic clearance was 7.2 ml/min (5.3 to 10.0 ml/min), and dialytic clearance was 104 ml/min (94 to 106 ml/min). The steady-state volume of distribution was 55.4 L (34.8 to 77.2 L). At MICs ≤1 µg/ml, probability of target attainment was >90% for each 48-hour AUC when vancomycin was administered as a 20-mg/kg loading dose followed by 10 mg/kg after every other SDHD. CONCLUSIONS: Vancomycin pharmacokinetic parameters in SDHD are consistent with data from thrice-weekly HD. A loading dose of 20 mg/kg followed by 10 mg/kg after every other SDHD provides adequate exposure for pathogens with MICs ≤1 µg/ml.

Merging health literacy with computer technology: self-managing diet and fluid intake among adult hemodialysis patients.

OBJECTIVE: The Dietary Intake Monitoring Application (DIMA) is an electronic dietary self-monitor developed for use on a personal digital assistant (PDA). This paper describes how computer, information, numerical, and visual literacy were considered in development of DIMA. METHODS: An iterative, participatory design approach was used. Forty individuals receiving hemodialysis at an urban inner-city facility, primarily middle-aged and African American, were recruited. RESULTS: Computer literacy was considered by assessing abilities to complete traditional/nontraditional PDA tasks. Information literacy was enhanced by including a Universal-Product-Code (UPC) scanner, picture icons for food with no UPC code, voice recorder, and culturally sensitive food icons. Numerical literacy was enhanced by designing DIMA to compute real-time totals that allowed individuals to see their consumption relative to their dietary prescription. Visual literacy was considered by designing the graphical interface to convey intake data over a 24-h period that could be accurately interpreted by patients. Pictorial icons for feedback graphs used objects understood by patients. PRACTICE IMPLICATIONS: Preliminary data indicate the application is extremely helpful for individuals as they self-monitor their intake. If desired, DIMA could also be used for dietary counseling.

Selection of dialysate and replacement fluids and management of electrolyte and Acid-base disturbances.

Often, too little consideration is given to the fluids used in all forms of continuous renal replacement therapy (CRRT). However, errors in fluid prescription, delivery, or creation can be rapidly fatal; in addition, fluid associated expenses can be the overriding cost in continuous renal replacement therapies. While a standard solution is frequently acceptable in most clinical circumstances, specific electrolyte and acid-base disturbances may direct changes in fluid delivery and composition. Decisions regarding fluids, whether dialysate versus replacement, including generation and composition of therapy are discussed in this review.