Download the Free Unbound MEDLINE PubMed App to your smartphone or tablet.
Available for iPhone, iPad, iPod touch, and Android.
Am J Kidney Dis [journal]
- Vancomycin-Resistant Enterococci Colonization Among Dialysis Patients: A Meta-analysis of Prevalence, Risk Factors, and Significance. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 16.
Vancomycin-resistant enterococci (VRE) have become important nosocomial pathogens causing outbreaks worldwide. Patients undergoing dialysis represent a vulnerable population due to their comorbid conditions, frequent use of antibacterial agents, and frequent contact with health care settings.Systematic review and meta-analysis of cross-sectional studies of screening for VRE colonization.Patients receiving long-term dialysis treatment.We performed a systematic literature search of PubMed and EMBASE databases to identify studies performing screening for VRE colonization among dialysis patients.Region, recent use of vancomycin or other antibiotics, previous hospitalization.(1) VRE colonization and (2) rate of VRE infection among colonized and noncolonized individuals. Relative effects were expressed as ORs and 95% CIs.We identified 23 studies that fulfilled the inclusion criteria and provided data for 4,842 dialysis patients from 100 dialysis centers. The pooled prevalence of VRE colonization was 6.2% (95% CI, 2.8%-10.8%), with significant variability between centers. The corresponding number for North American centers was 5.2% (95% CI, 2.8%-8.2%). Recent use of any antibiotic (OR, 3.62; 95% CI, 1.22-10.75), particularly vancomycin (OR, 5.15; 95% CI, 1.56-17.02), but also use of antibiotics other than vancomycin (OR, 2.92; 95% CI, 0.99-8.55) and recent hospitalization (OR, 4.55; 95% CI, 1.93-10.74) significantly increased the possibility of a VRE-positive surveillance culture. Colonized patients had a significantly higher risk of VRE infection (OR, 21.62; 95% CI, 5.33-87.69) than their noncolonized counterparts.In 19 of 23 studies, a low percentage of dialysis patients (<80%) consented to participate in the screening procedure. 4 of 8 studies in which patients were followed up for more than 1 month reported VRE infections and only 5 of 23 studies provided extractable data for antibiotic consumption prior to screening.VRE colonization is prevalent in dialysis centers. Previous antibiotic use, in particular vancomycin, and recent hospitalization are important predicting factors of colonization, whereas the risk of VRE infection is significantly higher for colonized patients.
- Kidney Function and Population-Based Outcomes of Initiating Oral Atenolol Versus Metoprolol Tartrate in Older Adults. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 15.
Atenolol and metoprolol tartrate are commonly prescribed β-blockers. Atenolol elimination depends on kidney function, whereas metoprolol tartrate does not. We hypothesized that compared to metoprolol tartrate, initiating oral atenolol treatment would be associated with more adverse events in older adults, with the association most pronounced in patients with lower baseline estimated glomerular filtration rates (eGFRs).Population-based matched retrospective cohort study.Older adults (mean age, 75 years) in Ontario, Canada, prescribed oral atenolol versus metoprolol tartrate from April 2002 through December 2011. The 2 groups were well matched (n=75,257 in each group), with no difference in 31 measured baseline characteristics. Patients with end-stage renal disease were ineligible, and 4.6% of patients had chronic kidney disease (median eGFR, 38mL/min/1.73m(2) assessed through a database algorithm).β-Blocker type and eGFR.A composite outcome of hospitalization with bradycardia or hypotension and all-cause mortality were assessed in 90-day follow-up.Compared to metoprolol tartrate, initiating atenolol treatment was not associated with higher risk of hospitalization with bradycardia or hypotension (incidence, 0.71% vs 0.79%; relative risk, 0.90; 95%CI, 0.80-1.01). Atenolol treatment initiation was associated with lower 90-day risk of mortality than metoprolol tartrate (incidence, 0.97% vs 1.44%; relative risk, 0.68; 95%CI, 0.61-0.74). Lower eGFR did not modify either association (P for interaction=0.5 and 0.6, respectively).Heart rate and blood pressure were not available in our data sources, and effects ascertained from observational studies are subject to residual confounding.Contrary to our expectation, we found that atenolol versus metoprolol tartrate was associated with lower 90-day risk of mortality in patients regardless of eGFR, with no difference in risk of hospitalization with bradycardia or hypotension.
- Protein Carbamylation in Kidney Disease: Pathogenesis and Clinical Implications. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 15.
Carbamylation describes a nonenzymatic posttranslational protein modification mediated by cyanate, a dissociation product of urea. When kidney function declines and urea accumulates, the burden of carbamylation naturally increases. Free amino acids may protect proteins from carbamylation, and protein carbamylation has been shown to increase in uremic patients with amino acid deficiencies. Carbamylation reactions are capable of altering the structure and functional properties of certain proteins and have been implicated directly in the underlying mechanisms of various disease conditions. A broad range of studies has demonstrated how the irreversible binding of urea-derived cyanate to proteins in the human body causes inappropriate cellular responses leading to adverse outcomes such as accelerated atherosclerosis and inflammation. Given carbamylation's relationship to urea and the evidence that it contributes to disease pathogenesis, measurements of carbamylated proteins may serve as useful quantitative biomarkers of time-averaged urea concentrations while also offering risk assessment in patients with kidney disease. Moreover, the link between carbamylated proteins and disease pathophysiology creates an enticing therapeutic target for reducing the rate of carbamylation. This article reviews the biochemistry of the carbamylation reaction, its role in specific diseases, and the potential diagnostic and therapeutic implications of these findings based on recent advances.
- Segmental Kidney Volumes Measured by Dynamic Contrast-Enhanced Magnetic Resonance Imaging and Their Association With CKD in Older People. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 10.
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a potentially powerful tool for analysis of kidney structure and function. The ability to measure functional and hypofunctional tissues could provide important information in groups at risk for chronic kidney disease (CKD), such as the elderly.Observational study with a cross-sectional design.493 volunteers (aged 72-94 years; 278 women; mean estimated glomerular filtration rate [eGFR], 67±15mL/min/1.73m(2); 40% with CKD) in the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study.DCE-MRI kidney segmentation data.eGFR, urine albumin-creatinine ratio (ACR), and risk factors for and complications of CKD.After adjustment for age, sex, and height, eGFR was related to kidney volume (ΔR²=0.19; P<0.001), cortex volume (ΔR²=0.14; P<0.001), medulla volume (ΔR²=0.18; P<0.001), and volume percentages of fibrosis (ΔR²=0.03; P<0.001) and fat (ΔR²=0.01; P=0.03). In similarly adjusted models, log(ACR) was related to kidney volume (ΔR²=0.02; P<0.001) and fibrosis volume percentage (ΔR²=0.03; P<0.001). Using multivariable regression models adjusted for eGFR, ACR, age, sex, and height, kidney volume was related positively to body mass index (B=29.9±2.1[SE]mL; P<0.001), smoking (B=19.7±7.7mL; P=0.01), and diabetes mellitus (B=14.8±7.1mL; P=0.04) and negatively to hematocrit (B=-4.4±2.1mL; P=0.04 [model R²=0.72; P<0.001]); relations were per 1-SD greater value of the variable. Fibrosis volume percentage was associated positively with body mass index (B=0.28±0.03; P<0.001), cardiac output (B=0.15±0.03; P<0.001), and heart rate (B=0.08±0.03; P=0.01) and negatively with hematocrit (B=-0.07±0.3; P=0.02) and augmentation index (B=-0.06±0.03; P=0.04 [model R²=0.49; P<0.001]); again, relations are per 1-SD greater value of the variable.Automatic segmentations were not validated by histology. The limited age range prevented meaningful interpretation of age effects on measured data or the automatic segmentation procedure.Kidney volume, cortex volume, and hypofunctional volume fraction assessed by DCE-MRI may provide information about CKD risk and prognosis beyond that provided by eGFR and urine ACR.
- Angiotensin Blockade and Progressive Loss of Kidney Function in Hemodialysis Patients: A Randomized Controlled Trial. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 8.
Glomerular filtration rate (GFR) declines during long-term dialysis treatment. In peritoneal dialysis, blockade of the renin-angiotensin-aldosterone system reduces GFR decline. Observational studies suggest that similar treatment may preserve kidney function in hemodialysis (HD).A multicenter, randomized, placebo-controlled, double-blinded trial, with 1-year follow-up.Adult HD patients with urine output >300mL/24h, HD vintage less than 1 year, and cardiac ejection fraction >30%. Patients were included from 6 HD centers.Patients were randomly assigned to placebo or the angiotensin II receptor blocker irbesartan, 300mg daily. Target systolic blood pressure (BP) was 140mm Hg.Primary outcomes were change in GFR measured as the mean of creatinine and urea renal clearance together with urine volume. Secondary outcomes were change in albuminuria, renin-angiotensin II-aldosterone hormone plasma levels, and time to anuria.Of 82 patients randomly assigned (41 patients in each group), 56 completed 1 year of treatment. The placebo and irbesartan groups were comparable at baseline in terms of sex balance (26 vs 30 men), mean age (62 vs 61 years), median HD vintage (137 vs 148 days), mean HD time (10 vs 11h/wk), median urine volume (1.19 vs 1.26L/d), and mean GFR (4.8 vs 5.7mL/min/1.73m(2)). The target BP level was reached in both groups and BP did not differ significantly between groups over time. Adverse-event rates were similar. GFR declined by a mean of 1.7 (95% CI, 1.2-2.3) and 1.8 (95% CI, 1.1-2.4) mL/min/1.73m(2) per year in the placebo and irbesartan groups, respectively. Mean difference (baseline values minus value at 12 months) between groups was -0.0 (95% CI, -0.8 to 0.8). In each group, 4 patients became anuric.GFR decline rates were lower than expected, reducing the power.At equal BP levels, we found that irbesartan treatment did not affect the decline in GFR or urine volume significantly during 1 year of treatment in HD patients. Irbesartan treatment was used safely in the studied population.
- Erythropoiesis-Stimulating Agent Use Among Non-Dialysis-Dependent CKD Patients Before and After the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT) Using a Large US Health Plan Database. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 8.
In a landmark study, TREAT (Trial to Reduce Cardiovascular Events With Aranesp Therapy) examined the use of erythropoiesis-stimulating agent (ESA) therapy to treat anemia among patients with chronic kidney disease (CKD) and found no benefit compared to placebo.A retrospective observational design was used to determine the impact of TREAT on clinical practice.A large US health plan database with more than 1.2 million claims for patients with non-dialysis-dependent CKD stages 3 and 4.ESA prescribing 2 years before and after publication of TREAT.Rate of ESA prescribing for ESA-naive and -prevalent cohorts.(1) Monthly ESA prescribing in the 2 years before and after publication of TREAT (ordinary least squares regression), (2) adjusted likelihood of prescribing ESA after TREAT (clustered logistic regression), and (3) probability of receiving ESA therapy based on anemia status (χ(2) test).For patients with CKD stage 3, the proportion prescribed ESA therapy declined from 17% pre-TREAT to 11% post-TREAT (a 38% decline), and for those with CKD stage 4, from 34% to 27% (a 22% decline). Prescribing of ESA therapy was declining even before TREAT, but the decline accelerated in the post-TREAT period (stage 3: change of slope, -0.08 [P<0.001]; stage 4: change of slope, -0.16 [P<0.001]). ESA prescribing declined after TREAT regardless of anemia status; among patients with hemoglobin levels <10g/dL, only 25% of patients with CKD stage 3 and 33% of patients with stage 4 were prescribed ESAs 2 years after TREAT, a notable 50% decline. After adjusting for all covariates, the probability of prescribing ESAs was 35% lower during the 2-year period after versus before publication of TREAT (OR, 0.65; 95% CI, 0.63-0.67).The cumulative effect of adverse safety concerns in the period before TREAT also influenced physician prescribing of ESA therapy and could not be separated from the influence of TREAT.TREAT appears to be a watershed study that was followed by a marked decline in ESA prescribing for patients with CKD.
- Extracorporeal Treatment for Barbiturate Poisoning: Recommendations From the EXTRIP Workgroup. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 3.
The EXTRIP (Extracorporeal Treatments in Poisoning) Workgroup conducted a systematic review of barbiturate poisoning using a standardized evidence-based process to provide recommendations on the use of extracorporeal treatment (ECTR) in patients with barbiturate poisoning. The authors reviewed all articles, extracted data, summarized key findings, and proposed structured voting statements following a predetermined format. A 2-round modified Delphi method was used to reach a consensus on voting statements, and the RAND/UCLA Appropriateness Method was used to quantify disagreement. 617 articles met the search inclusion criteria. Data for 538 patients were abstracted and evaluated. Only case reports, case series, and nonrandomized observational studies were identified, yielding a low quality of evidence for all recommendations. Using established criteria, the workgroup deemed that long-acting barbiturates are dialyzable and short-acting barbiturates are moderately dialyzable. Four key recommendations were made. (1) The use of ECTR should be restricted to cases of severe long-acting barbiturate poisoning. (2) The indications for ECTR in this setting are the presence of prolonged coma, respiratory depression necessitating mechanical ventilation, shock, persistent toxicity, or increasing or persistently elevated serum barbiturate concentrations despite treatment with multiple-dose activated charcoal. (3) Intermittent hemodialysis is the preferred mode of ECTR, and multiple-dose activated charcoal treatment should be continued during ECTR. (4) Cessation of ECTR is indicated when clinical improvement is apparent. This report provides detailed descriptions of the rationale for all recommendations. In summary, patients with long-acting barbiturate poisoning should be treated with ECTR provided at least one of the specific criteria in the first recommendation is present.
- Association of Albumin-Creatinine Ratio and Cystatin C With Change in Ankle-Brachial Index: The Multi-Ethnic Study of Atherosclerosis (MESA). [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 3.
Low ankle-brachial index (ABI) is a reflection of atherosclerotic disease, and high ABI is an indicator of calcified vessels. The associations of albuminuria and cystatin C level with incidence of either low or high ABI are unknown.Prospective longitudinal cohort study.MESA (Multi-Ethnic Study of Atherosclerosis) enrolled community-dwelling adults (N=6,814) aged 45-84 years who were free of clinical cardiovascular disease at baseline.Baseline albumin-creatinine ratio (ACR) and serum cystatin C level.Development of low (<0.90), and high (>1.40) ABI using multinomial regression among persons with ABI of 0.90-1.40 at baseline.During 9.8 years of follow-up, 221 and 89 participants progressed to low and high ABIs, respectively. Baseline ACR and cystatin C level were higher among progressors compared with nonprogressors. In multivariable analyses, doubling of ACR was associated with increased risk of progression to low (OR, 1.08; 95% CI, 0.99-1.20) and high (OR, 1.16; 95% CI, 1.01-1.32) ABIs. Compared to the lowest quintile, the highest quintile of ACR had a significantly increased risk of progression to low (OR, 1.79; 95% CI, 1.03-3.12) and high (OR, 2.76; 95% CI, 1.32-5.77) ABIs. Higher cystatin C levels were associated with progression to low (OR per 1-SD greater, 1.12; 95% CI, 1.00-1.26) but not high (OR per 1-SD greater, 1.01; 95% CI, 0.81-1.25) ABI, but the highest quintile of cystatin C was not associated independently with either outcome.Single measure of albuminuria and low number of progressors to high ABI.In adults free of clinical cardiovascular disease, albuminuria was a strong independent risk factor for the development of both high and low ABIs, important and different measures of peripheral artery disease.
- Development and Evaluation of the CAHPS (Consumer Assessment of Healthcare Providers and Systems) Survey for In-Center Hemodialysis Patients. [JOURNAL ARTICLE]
- Am J Kidney Dis 2014 Jul 3.
The US Centers for Medicare & Medicaid Services assess patient experiences of care as part of the end-stage renal disease prospective payment system and Quality Incentive Program. This article describes the development and evaluation of the Consumer Assessment of Healthcare Providers and Systems (CAHPS) In-Center Hemodialysis Survey.We conducted formative research to generate survey questions and performed statistical analyses to evaluate the survey's measurement properties.Formative research included focus groups, cognitive interviews, and field testing the survey with dialysis patients.We assessed internal consistency reliability (Cronbach alpha) and center-level reliability for 3 multi-item scales. We evaluated construct validity using correlations of the scales with global ratings of the kidney doctor, staff, and dialysis center.Response rate was 46% (1,454 completed surveys). Analyses support 3 multi-item scales: Nephrologists' Communication and Caring (7 items, alpha=0.89), Quality of Dialysis Center Care and Operations (22 items, alpha=0.93), and Providing Information to Patients (11 items, alpha=0.75). The communication scale was correlated the most strongly with the global rating of the "kidney doctor" (r=0.78). The Dialysis Center Care and Operations scale was correlated most strongly with global ratings of staff (r=0.75) and the center (r=0.69). Providing Information to Patients was correlated most strongly with the global rating of the staff (r=0.41).A relatively small number of patients completed the survey in Spanish.This study provides support for the reliability and validity of the CAHPS In-Center Hemodialysis Survey for assessing patient experiences of care at dialysis facilities. The survey can be used to compare care provided at different facilities.
- Diagnosis and Treatment of Hyponatremia. [EDITORIAL]
- Am J Kidney Dis 2014 Jul 2.