Kevin C. Abbott

Association of Prescription of Oral Sodium Polystyrene Sulfonate With Sorbitol in an Inpatient Setting With Colonic Necrosis: A Retrospective Cohort Study

BACKGROUNDnColonic necrosis has been reported after sodium polystyrene sulfonate (SPS)/sorbitol use, but the incidence and relative risk (RR) are not established.nnnSTUDY DESIGNnRetrospective cohort study.nnnSETTING & PARTICIPANTSn123,391 adult inpatients at a tertiary medical center.nnnPREDICTORnReceipt of SPS prescriptions (exposed) or a prescription other than SPS (unexposed internal comparison group) between September 1, 2001, and October 31, 2010.nnnOUTCOMESnThe main outcome measure was tissue-confirmed diagnosis of colonic necrosis, considered SPS-associated if SPS was prescribed 30 or fewer days before tissue accession date.nnnMEASUREMENTSnDemographics, serum chemistry test results, hospital location, and International Classification of Diseases, Ninth Revision diagnostic codes.nnnRESULTSnSPS was prescribed to 2,194 inpatients. 82 inpatient colonic necrosis cases were identified. 3 received oral SPS (1 gram per 4 milliliters of 33% sorbitol) 30 or fewer days before the colonic necrosis accession date (3.7% of inpatient colonic necrosis cases). The data were linked with 123,391 individuals who received inpatient prescriptions between the same dates. Colonic necrosis incidence was 0.14% (95% CI, 0.03%-0.40%) in those prescribed SPS versus 0.07% (95% CI, 0.05-0.08%) in those not prescribed SPS (RR, 2.10; 95% CI, 0.68-6.48; P = 0.2). The number needed to harm was 1,395 (95% CI, 298-5,100). Subgroup analysis (age >65 years; estimated glomerular filtration rate, <30 mL/min/1.73 m(2), intensive care unit admission, or surgical ward status) did not show significant associations. Sample-size analysis indicated that 4,974 SPS-treated individuals older than 65 years and a comparison group 10 times larger would be required for rigorous multivariate analysis of SPS-associated colonic necrosis risk.nnnLIMITATIONSnIndividuals with colonic necrosis admitted to non-Department of Defense hospitals would not have been ascertained. Only individuals who had colonic biopsy or surgical tissue submitted for pathologic review could be ascertained as having colonic necrosis.nnnCONCLUSIONSnSPS-associated colonic necrosis is rare, and inpatient SPS/sorbitol prescription was not associated significantly with an increased RR of colonic necrosis in this retrospective cohort analysis. Multivariate analysis would require retrospective clinical cohorts from larger or more than one hospital system(s).

Survival Disparity of African American Versus Non–African American Patients With ESRD Due to SLE

BACKGROUNDnA recent study showed an increased risk of death in African Americans compared with whites with end-stage renal disease (ESRD) due to lupus nephritis (LN). We assessed the impact of age stratification, socioeconomic factors, and kidney transplantation on the disparity in patient survival among African American versus non-African American patients with LN-caused ESRD, compared with other causes.nnnSTUDY DESIGNnRetrospective cohort study.nnnSETTING & PARTICIPANTSnUsing the US Renal Data System database, we identified 12,352 patients with LN-caused ESRD among 1,132,202 patients who initiated maintenance dialysis therapy from January 1, 1995, through December 31, 2006, and were followed up until December 31,xa02010.nnnPREDICTORSnBaseline demographics and comorbid conditions, Hispanic ethnicity, socioeconomic factors (employment status, Medicare/Medicaid insurance, and area-level median household income based on zip code as obtained from the 2000 US census), and kidney transplantation as a time-dependent variable.nnnOUTCOMEnAll-cause mortality.nnnMEASUREMENTSnMultivariable Cox and competing-risk regressions.nnnRESULTSnMean duration of follow-up in the LN-caused ESRD and other-cause ESRD cohorts were 6.24±4.20 (SD) and 4.06±3.61 years, respectively. 6,106 patients with LN-caused ESRD (49.43%) and 853,762 patients with other-cause ESRD (76.24%) died during the study period (P<0.001). Patients with LN-caused ESRD were significantly younger (mean age, 39.92 years) and more likely women (81.65%) and African American (48.13%) than those with other-cause ESRD. In the fully adjusted multivariable Cox regression model, African American (vs non-African American) patients with LN-caused ESRD had significantly increased risk of death at age 18 to 30 years (adjusted HR, 1.43; 95% CI, 1.24-1.65) and at age 31 to 40 years (adjusted HR, 1.17; 95% CI, 1.02-1.34). Among patients with other-cause ESRD, African Americans were at significantly increased risk at age 18 to 30 years (adjusted HR, 1.17; 95% CI, 1.11-1.22).nnnLIMITATIONSnWe used zip code-based median household income as a surrogate for patient income. Residual socioeconomic confounders may exist.nnnCONCLUSIONSnAfrican Americans are at significantly increased risk of death compared with non-African Americans with LN-caused ESRD at age 18 to 40 years, a racial disparity risk that is 10 years longer than that in the general ESRD population. Accounting for area-level median household income and transplantation significantly attenuated the disparity in mortality of African American versus non-African American patients with LN-caused ESRD.

Elevated Subclinical Double-Stranded DNA Antibodies and Future Proliferative Lupus Nephritis

BACKGROUND AND OBJECTIVESnElevated anti-double-stranded DNA (dsDNA) antibody and C-reactive protein are associated with proliferative lupus nephritis (PLN). Progression of quantitative anti-dsDNA antibody in patients with PLN has not been compared with that in patients with systemic lupus erythematosus (SLE) without LN before diagnosis. The temporal relationship between anti-dsDNA antibody and C-reactive protein elevation has also not been evaluated.nnnDESIGN, SETTING, PARTICIPANTS, & MEASUREMENTSnThis case-control Department of Defense Serum Repository (established in 1985) study compared longitudinal prediagnostic quantitative anti-dsDNA antibody and C-reactive protein levels in 23 patients with biopsy-proven PLN (Walter Reed Army Medical Center, 1993-2009) with levels in 21 controls with SLE but without LN matched for patient age, sex, race, and age of serum sample. The oldest (median, 2601 days; 25%, 1245 days, 75%, 3075 days), the second to last (368; 212, 635 days), and the last (180; 135, 477 days) serum sample before diagnosis were analyzed.nnnRESULTSnMore patients with PLN had an elevated anti-dsDNA antibody level than did the matched controls at any point (78% versus 5%; P<0.001), <1 year (82% versus 8%; P<0.001), 1-4 years (53% versus 0%; P<0.001), and >4 years (33% versus 0%; P=0.04) before diagnosis. A rate of increase >1 IU/ml per year (70% versus 0%; P<0.001) was most specific for PLN. The anti-dsDNA antibody levels increased before C-reactive protein did in most patients with an antecedent elevation (92% versus 8%; P<0.001).nnnCONCLUSIONSnElevated anti-dsDNA antibody usually precedes both clinical and subclinical evidence of proliferative LN, which suggests direct pathogenicity. Absolute anti-dsDNA antibody level and rate of increase could better establish risk of future PLN in patients with SLE.

Risk of intracranial hemorrhage associated with autosomal dominant polycystic kidney disease in patients with end stage renal disease

BackgroundAn analysis of intracranial hemorrhage (ICH) in a national sample of autosomal dominant polycystic kidney disease (ADPKD) patients receiving long-term dialysis has not been reported. It is often assumed that patients with ADPKD are not at increased risk of ICH after starting dialysis. We hypothesized that patients with ADPKD would have a higher subsequent risk of ICH even after the start of chronic dialysis.MethodsRetrospective cohort study of Medicare primary patients with and without ADPKD in the United States Renal Data System (USRDS), initiated on chronic dialysis or transplanted between 1 January 1999 and 3 July 2009, and followed until 31 December 2009. Covariates included age, gender, race, prior stroke, diabetes mellitus, dialysis modality, body mass index, serum albumin and other co-morbid conditions from the Medical Evidence Form. Primary outcome was ICH, based on inpatient and outpatient Medicare claims, and all-cause mortality. Kaplan-Meier analysis was used for unadjusted assessment of time to events. Cox regression was used for assessment of factors associated with ICH and mortality. We performed competing risk regression using kidney transplant and death as competing risks. Kidney transplant was also modeled as a time-dependent covariate in Cox regression.ResultsCompeting risk regression demonstrated that ADPKD had a subhazard ratio 2.97 for ICH (95% CI 2.27-3.89). Adjusted Cox analysis showed that ADPKD patients had an AHR for death of 0.59 vs. non-ADPKD patients (95% CI 0.57-0.61).ConclusionsADPKD is a significant risk factor for ICH among patients on maintenance dialysis. Our Medicare primary cohort was older than in previous studies of intracranial aneurysm rupture among ADPKD patients. There are also limitations inherent to using the USRDS database.

Practice Patterns in Evaluation of Living Kidney Donors in United Network for Organ Sharing-Approved Kidney Transplant Centers

Introduction: The current pattern of evaluation for living kidney donors was investigated. Methods: We designed a 37-question electronic survey to collect information about living kidney donor evaluation. Of the 181 United Network for Organ Sharing (UNOS)-approved centers, 72 responded. Survey responses were coded and downloaded into SPSS. Data was expressed as means and standard deviations or the percentage of centers with specific responses. Results: 66% of the centers used a cut-off of <80 ml/min for exclusion of living kidney donors. 24-hour urine measuring creatinine clearance (CrCl) was the most common screening method for glomerular filtration rate (GFR) assessment in potential living donors. 56% of the centers excluded donors with blood pressure (BP) >140/90, whereas 22.7 and 7.1% excluded patients with pre-hypertension with a cut-off BP of 130/85 and 120/80, respectively. 66% of the centers used 24-hour urine creatinine to assess for proteinuria. 20% of the centers accepted living kidney donors with microalbuminuria and 84% accepted patients with a history of nephrolithiasis. 24% of the centers reported use of formal cognitive testing of potential living donors. Discussion: There were significant variations in exclusion criteria based on GFR, history of kidney stones, body mass index, BP and donors with urinary abnormalities. The definitions for hematuria and proteinuria were variable. There is a need for uniformity in selection and for a living donor registry. We also recommend raising the cut-off for estimated GFR to 90 ml/min to account for 10–15% overestimation when CrCl is used.

Impact of isometric handgrip exercises on cephalic vein diameter in non-AVF candidates, a pilot study

Purpose Incident arteriovenous fistula (AVF) rates remain low. AVF placement is often not attempted because of small cephalic vein (CV) diameter. We postulated that isometric handgrip exercises would increase forearm CV diameter and allow successful AVF creation in non-AVF candidates. Methods Adult subjects without prior vascular access (eGFR<25mL/min/1.73m2; CV<2.5mm) were prospectively enrolled. They performed daily handgrip exercises in the preferred access arm (EA), with the nonexercised arm (NEA) as control. Adherence was assessed by exercise logs and grip strength. CV diameter was measured at baseline, four and eight weeks by ultrasound. The primary endpoint was the mean increase in CV diameter. Secondary endpoints were mean CV diameter increase from baseline, increased proportion of potential AVF sites and successful AVF placement. Results A total of 17 subjects were enrolled and 15 completed the study. EA grip strength increased significantly. Mean CV diameter increased in both the EA and NEA by 0.48-0.59 and 0.71-0.81 mm (P=NS), respectively. Compared to baseline, all CV diameters increased significantly (P<.05) after four weeks. In the EA, mean distal and proximal CV increased from 1.66 to 2.13 mm and from 2.22 to 2.81 mm, respectively. Similar changes were noted in the NEA. There were also significant increases in the number of sites and subjects eligible for AVF creation. Five subjects had successful AVF placement. Conclusions Isometric handgrip exercises resulted in significant CV diameter increases after four weeks, in both the EA and the NEA and potentially allows for AVF creation in those not previously deemed candidates.

Implementation of nephrology subspecialty curricular milestones.

Beginning in the 2014-2015 training year, the US Accreditation Council for Graduate Medical Education (ACGME) required that nephrology Clinical Competency Committees assess fellows progress toward 23 subcompetency context nonspecific internal medicine subspecialty milestones. Fellows advancement toward the ready for unsupervised practice target milestone now is tracked in each of the 6 competencies: Patient Care, Medical Knowledge, Professionalism, Interpersonal Communication Skills, Practice-Based Learning and Improvement, and Systems-Based Practice. Nephrology program directors and subspecialty societies must define nephrology-specific curricular milestones, mapped to the nonspecific ACGME milestones. Although the ACGME goal is to produce data that can discriminate between successful and underperforming training programs, the approach is at risk to produce biased, inaccurate, and unhelpful information. We map the ACGME internal medicine subspecialty milestones to our previously published nephrology-specific milestone schema and describe entrustable professional activities and other objective assessment tools that inform milestone decisions. Mapping our schema onto the ACGME subspecialty milestone reporting form allows comparison with the ACGME subspecialty milestones and the curricular milestones developed by the American Society of Nephrology Program Directors. Clinical Competency Committees may easily adapt and directly translate milestone decisions reached using our schema onto the ACGME internal medicine subspecialty competency milestone-reporting format.

Outcomes After Post-Traumatic AKI Requiring RRT in United States Military Service Members

BACKGROUND AND OBJECTIVESnMortality and CKD risk have not been described in military casualties with post-traumatic AKI requiring RRT suffered in the Iraq and Afghanistan wars.nnnDESIGN, SETTING, PARTICIPANTS, & MEASUREMENTSnThis is a retrospective case series of post-traumatic AKI requiring RRT in 51 military health care beneficiaries (October 7, 2001-December 1, 2013), evacuated to the National Capital Region, documenting in-hospital mortality and subsequent CKD. Participants were identified using electronic medical and procedure records.nnnRESULTSnAge at injury was 26±6 years; of the participants, 50 were men, 16% were black, 67% were white, and 88% of injuries were caused by blast or projectiles. Presumed AKI cause was acute tubular necrosis in 98%, with rhabdomyolysis in 72%. Sixty-day all-cause mortality was 22% (95% confidence interval [95% CI], 12% to 35%), significantly less than the 50% predicted historical mortality (P<0.001). The VA/NIH Acute Renal Failure Trial Network AKI integer score predicted 60-day mortality risk was 33% (range, 6%-96%) (n=49). Of these, nine died (mortality, 18%; 95% CI, 10% to 32%), with predicted risks significantly miscalibrated (P<0.001). The area under the receiver operator characteristic curve for the AKI integer score was 0.72 (95% CI, 0.56 to 0.88), not significantly different than the AKI integer score model cohort (P=0.27). Of the 40 survivors, one had ESRD caused by cortical necrosis. Of the remaining 39, median time to last follow-up serum creatinine was 1158 days (range, 99-3316 days), serum creatinine was 0.85±0.24 mg/dl, and eGFR was 118±23 ml/min per 1.73 m(2). No eGFR was <60 ml/min per 1.73 m(2), but it may be overestimated because of large/medium amputations in 54%. Twenty-five percent (n=36) had proteinuria; one was diagnosed with CKD stage 2.nnnCONCLUSIONSnDespite severe injuries, participants had better in-hospital survival than predicted historically and by AKI integer score. No patient who recovered renal function had an eGFR<60 ml/min per 1.73 m(2) at last follow-up, but 23% had proteinuria, suggesting CKD burden.

Expanding the Role of Objectively Structured Clinical Examinations in Nephrology Training

Objectively structured clinical examinations (OSCEs) are widely used in medical education, but we know of none described that are specifically for nephrology fellowship training. OSCEs use simulation to educate and evaluate. We describe a technically simple, multidisciplinary, low-cost OSCE developed by our program that contains both examination and training features and focuses on management and clinical knowledge of rare hemodialysis emergencies. The emergencies tested are venous air embolism, blood leak, dialysis membrane reaction, and hemolysis. Fifteen fellows have participated in the OSCE as examinees and/or preceptors since June 2010. All have passed the exercise. Thirteen responded to an anonymous survey in July 2013 that inquired about their confidence in managing each of the 4 tested emergencies pre- and post-OSCE. Fellows were significantly more confident in their ability to respond to the emergencies after the OSCE. Those who subsequently saw such an emergency reported that the OSCE experience was somewhat or very helpful in managing the event. The OSCE tested and trained fellows in the recognition and management of rare hemodialysis emergencies. OSCEs and simulation generally deserve greater use in nephrology subspecialty training; however, collaboration between training programs would be necessary to validate such exercises.

Assessing Achievement in Nephrology Training: Using Clinic Chart Audits to Quantitatively Screen Competency

BACKGROUNDnEntrustable professional activities (EPAs) are complex tasks representing vital physician functions in multiple competencies, used to demonstrate trainee development along milestones. Managing a nephrology outpatient clinic has been proposed as an EPA for nephrology fellowship training.nnnSTUDY DESIGNnRetrospective cohort study of nephrology fellow outpatient clinic performance using a previously validated chart audit tool.nnnSETTING & PARTICIPANTSnOutpatient encounter chart audits for training years 2008-2009 through 2012-2013, corresponding to participation in the Nephrology In-Training Examination (ITE). A median of 7 auditors (attending nephrologists) audited a mean of 1,686±408 (SD) charts per year. 18 fellows were audited; 12, in both of their training years.nnnPREDICTORSnProportion of chart audit and quality indicator deficiencies.nnnOUTCOMESnLongitudinal deficiency and ITE performance.nnnMEASUREMENTS & RESULTSnAmong fellows audited in both their training years, chart audit deficiencies were fewer in the second versus the first year (5.4%±2.0% vs 17.3%±7.0%; P<0.001) and declined between the first and second halves of the first year (22.2%±6.4% vs 12.3%±9.5%; P=0.002). Most deficiencies were omission errors, regardless of training year. Quality indicator deficiencies for hypertension and chronic kidney disease-associated anemia recognition and management were fewer during the second year (P<0.001). Yearly audit deficienciesxa0≥5% were associated with an ITE score less than the 25th percentile for second-year fellows (P=0.03), with no significant association for first-year fellows. Auditor-reported deficiencies declined between the first and second halves of the year (17.0% vs 11.1%; P<0.001), with a stable positive/neutral comment rate (17.3% vs 17.8%; P=0.6), suggesting that the decline was not due to auditor fatigue.nnnLIMITATIONSnRetrospective design and small trainee numbers.nnnCONCLUSIONSnManaging a nephrology outpatient clinic is an EPA. The chart audit tool was used to assess longitudinal fellow performance in managing a nephrology outpatient clinic. Failure to progress may be quantitatively identified and remediated. The tool identifies deficiencies in all 6 competencies, not just medical knowledge, the primary focus of the ITE and the nephrology subspecialty board examination.