Clinical and Analytical Impact of Moving from Jaffe to Enzymatic Serum Creatinine Methodology.

BACKGROUND: Identification and monitoring of chronic kidney disease (CKD) requires accurate quantification of serum creatinine. The poor specificity of Jaffe creatinine methods is well documented, and guidelines recommend enzymatic methodology. We describe our experience of moving from Jaffe to enzymatic creatinine methodology. We present comparison of >5000 paired Jaffe and enzymatic creatinine results, examine interferences, and attempt to assess clinical consequences of changing methodology. METHODS: Overall, 5303 serum samples received for routine creatinine measurement were analyzed using Jaffe and enzymatic methods with an Abbott Architect autoanalyzer. Associated results for glucose, total bilirubin, triglycerides, total protein, and hemolytic, icteric, and lipemic indexes were extracted from the laboratory database. CKD staging was estimated for each sample to assess potential clinical effects. RESULTS: The methods correlated well (r = 0.996) and showed good agreement (Passing-Bablok fit, y = 0.935x + 0.074). Paired analysis, however, showed significant differences (P < 0.001), and approximately 20% of results differed by more than ±10%. Multivariate analysis demonstrated independent associations between difference in creatinine results, glucose (P < 0.0001), and hemolytic index (P = 0.009). Glucose demonstrated positive interference in the Jaffe method, and hemolysis produced negative interference in the enzymatic method. Little or no association was observed with other analytes. CKD staging differed in 4% of samples. CONCLUSIONS: Differences between Jaffe and enzymatic serum creatinine results exceed the recommended 5% target for a significant proportion of samples, particularly at concentrations <1.13 mg/dL (100 µmol/L). Both glucose and hemolysis contribute to the variance in results. Although the clinical impact of these differences seems small, laboratories should continue moving toward enzymatic creatinine estimation to ensure the best estimate of renal function.

Idiopathic membranous nephropathy and nephrotic syndrome: outcome in the era of evidence-based therapy.

BACKGROUND: Contemporary studies analysing the long-term outcomes of patients with idiopathic membranous nephropathy and nephrotic syndrome in the era of evidence-based antiproteinuric and immunosuppressive therapies are sparse. Controversy also persists regarding which immunosuppression (IS) regimen to use. In this retrospective cohort study, we aimed to characterize time to partial remission (PR), complete remission (CR), requirement for renal replacement therapy (RRT) or death. We aimed to assess which factors predicted RRT or death and determine the impact of IS on outcome. METHODS: Ninety-five consecutive adult patients attending two centres between 1997 and 2008 were identified. Baseline demographics and subsequent treatment and outcome were recorded. RESULTS: Ninety-five percent of patients were prescribed angiotensin-converting enzyme inhibitors and/or angiotensin-receptor blocker (ACEI/ARB) therapy, 78% statin therapy, 70% antiplatelets and 38% IS. The 5-year actuarial rates for PR, CR, RRT and death were 76.4, 24.4, 11.9 and 16.8%, respectively. In patients achieving at least one PR, the 5-year actuarial risk of relapse was 32.8%. Using multivariate survival analysis, achievement of remission was the factor most strongly associated with reduced risk of RRT or death. There was no significant difference in outcomes between patients who did or did not receive IS, although patients receiving IS had more severe disease. Contrary to published findings, 81.8% of patients treated with the Ponticelli regimen (6 months of alternating prednisolone and cyclophosphamide or chlorambucil) suffered significant treatment-related complications compared with 19% of patients prescribed the Cattran regimen (prolonged combined low-dose prednisolone and cyclosporine). CONCLUSIONS: Using an approach of widespread ACEI/ARB treatment and targeted IS, 76% of patients can expect to have achieved at least one PR by 5 years. Achievement of remission is the factor most strongly associated with reduced risk of RRT and death. Treatment with IS is associated with significant treatment complications.

A prospective observational study of catheter-related bacteraemia and thrombosis in a haemodialysis cohort: univariate and multivariate analyses of risk association.

BACKGROUND: Central venous catheterization is a fundamental component in delivering haemodialysis yet is associated with significantly higher complication rates than other methods of vascular access. In this study, we report results of univariate and multivariate analyses designed to identify and quantify independent risk association for catheterization type, clinical variables and laboratory variables with regard to the development of catheter-related bacteraemia (CRB) and catheter failure due to poor haemodialysis flow. METHODS: A 2-year prospective study of all incident haemodialysis vascular access catheter insertions was conducted. Laboratory and clinical variables were recorded at catheter insertion, and the clinical course was followed up to the point of catheter removal. CRB and catheter failure due to poor flow were recorded as outcome events. Univariate and multivariate analyses were used to test for association between clinical and laboratory variables and outcome. RESULTS: Forty-four thousand five hundred seventy-six catheter days were accumulated over the study period. Multivariate analysis demonstrated an independent association between non-tunnelled catheterization procedures and adverse outcomes compared with tunnelled central venous catheter insertions. Elevated modified Charlson comorbidity score was independently associated with the development of CRBc. Elevated C-reactive protein and low haemodialysis blood pump flow were independently associated with catheter failure due to poor flow. CONCLUSIONS: The data demonstrate that tunnelled central venous catheter insertions have an association with lower complication rates than non-tunnelled central venous catheter insertions that is independent of whether patients have acute or chronic renal failure, or high levels of comorbidity.

The influence of comorbidity on the risk of access-related bacteremia in chronic hemodialysis patients.

Access-related bacteremia is an important cause of morbidity in chronic hemodialysis patients. The incidence of bacteremia is higher in patients dialyzing through a tunneled central venous catheter (TCVC) compared with an arteriovenous fistula (AVF). Our aim was to explore if this is explained by patient comorbidity. Two groups of chronic hemodialysis outpatients were compared: all patients who dialyzed through a TCVC at any time during 2003 and were fit enough to subsequently have a functioning AVF or renal transplant even if it was after 2003 (Group 1; n=93); and all patients who dialyzed through a TCVC in 2003 and were not fit enough to have a functioning AVF or renal transplant (Group 2; n=119). Episodes of bacteremia (n=71) were identified and those not related to access were excluded. Patients in Group 1 were younger than Group 2 (57.5 years vs. 64.8 years; P=0.001). The incidences of bacteremia in Groups 1 and 2 were, respectively, 0.31 and 0.44 episodes per 1000 patient days while dialyzing through an AVF (P=0.77), and 2.21 and 2.27 per 1000 days while dialyzing through a TCVC (P=0.91). The 3-year actual survival from January 1, 2003 to January 1, 2006 was significantly higher in Group 1 than in Group 2 (80.6% vs. 26.1%; P<0.0001) confirming the higher comorbidity of the patients in Group 2. Patients dialyzing through a TCVC (compared with an AVF) have a significantly higher risk of access-related bacteremia, irrespective of comorbidity.

Palliative nurses' perceptions of the nature and effects of their work.

This paper presents some of the qualitative findings from a recent research project, which explored the nature and effects of palliative nursing care for nurses, in New South Wales, Australia. By using story telling as the research methodology the participants related their experiences about palliative care nursing practice in which they felt they did or did not make a difference to the people in their care. The results of this project clearly demonstrated that the nature of palliative nursing is expressed by nurses dealing with death, making connections, making contracts, demonstrating advocacy, building interpersonal relationships, requiring family and colleague support and involvement in issues. The effects of palliative nursing were described as whether nurses were able to find solutions; facilitate breakthroughs, acceptance and support; reflect of their values and feelings.