Diameter of inflow as a predictor of radiocephalic fistula flow.

INTRODUCTION:: The optimal method for vascular access surveillance is largely unknown. A previous case-control study suggested a simplified anatomical measure obtained by Doppler ultrasound-the narrowest segment of the circuit or "minimal luminal diameter" may identify patients with a dysfunctional radiocephalic arteriovenous fistula. The relationship between minimal luminal diameter and access flow (Qa) in the radiocephalic arteriovenous fistula has not previously been studied. METHODS:: Patients undergoing Doppler ultrasound of a radiocephalic arteriovenous fistula over an 8-month period were identified retrospectively. Minimal luminal diameter was identified and demographic and clinical data were collected. Qa was estimated by Doppler estimation of brachial artery flow. The relationship between minimal luminal diameter and Qa was examined by correlation and using different levels of minimal luminal diameter as a simplified measure to detect or exclude low Qa (<600 mL/min). RESULTS:: A total of 81 Doppler ultrasound scans were performed. In all, 26 scans demonstrated brachial artery flow <600 mL/min. Simple logistic regression indicated a weak statistical relationship between the minimal luminal diameter and Qa (R2 = 0.27, p < 0.01). Minimal luminal diameter performed poorly as a marker of low Qa with low specificity, however, showed high negative predictive value for ruling out low Qa at a minimal luminal diameter of 3.2 mm or higher (94%). Qa estimated by brachial artery flow correlated well with Qa estimated by indicator dilution (R2 = 0.83, p < 0.01) without significant mean difference or proportional bias. CONCLUSION:: Minimal luminal diameter correlates weakly with Qa. Low minimal luminal diameter values should not be used in isolation to determine low Qa for a radiocephalic arteriovenous fistula. Conversely, minimal luminal diameter >3.2 mm largely excludes a low-flow radiocephalic arteriovenous fistula in this cohort. Brachial artery flow is a reasonable measure of Qa in comparison with indicator dilution.

Patient experiences of training and transition to home haemodialysis: A mixed-methods study.

AIM: This study aims to describe patients' perspectives on the transition to home haemodialysis. METHODS: Up to three sequential semi-structured interviews were conducted with 20 patients during the transition to home haemodialysis at an Australian renal unit. Transcripts were analysed thematically. Participants completed a satisfaction questionnaire after commencing home haemodialysis. RESULTS: We identified six themes: persevering despite trepidations (diminishing intimidation of machinery, acquiescing to fatal risks, reconciling fears of cannulation, dispelling concerns of neglect and tolerating necessary concessions); optimizing the learning pathway (practising problem solving, learning from mistakes, grasping technical complexity, minimizing cognitive overload and progressing at own pace); developing confidence (believing in own abilities, adapting to independence, depending on caregiver partnership and faith in crisis support); interrupted transition momentum (lacking individual attention, language barriers, installation delays, interfering illness and complications and acclimatizing to new conditions); noticing immediate gains (reclaiming lifestyle normality, satisfying self-sufficiency, personalizing treatment regime and thriving in a positive environment); and depleting resources and energy (exhaustion with gruelling routine, confronting medicalization of the home, draining financial reserves and imposing family burden). Fewer than 30% of respondents indicated low satisfaction with staff availability domains, staff interpersonal domains or technical domains. CONCLUSION: Home haemodialysis training fosters confidence in patients; however, many patients experience stress because of medical isolation, treatment responsibilities, family impositions and financial difficulties. Addressing patient's on-going psychosocial concerns may alleviate burdens on patients and their families during the transition to home haemodialysis.

The CD40-CD154 co-stimulation pathway mediates innate immune injury in adriamycin nephrosis.

BACKGROUND: Blockade of CD40-CD40 ligand (CD154) interactions protects against renal injury in adriamycin nephropathy (AN) in immunocompetent mice. To investigate whether this protection relied on adaptive or cognate immunity, we tested the effect of CD40-CD154 blockade in severe combined immunodeficient (SCID) mice. METHODS: SCID mice were divided into three groups: normal, AN + hamster IgG (ADR+IgG group) and AN + anti-CD154 antibody (MR1) (ADR+MR1 group). AN was induced by tail vein injection of 5.2 mg/kg of adriamycin (ADR). Hamster IgG (control Ab) or MR1 was administered intraperitoneally on days 5, 7, 9 and 11 after ADR injection. Histological and functional data were collected 4 weeks after ADR injection. In vitro experiments tested the effect of soluble and cell-bound CD154 co-cultured with CD40-expressing cells [macrophages, mesangial cells and renal tubular epithelial cells (RTEC)]. RESULTS: All experimental animals developed nephropathy. Compared to the ADR+IgG group, ADR+MR1 animals had significantly less histological injury (glomerulosclerosis and tubular atrophy) and functional injury (creatinine clearance). Kidneys of ADR+MR1 animals had significantly less macrophage infiltration than those of ADR+IgG animals. Interestingly, expression of CD40 and CD41 (a platelet-specific marker) was significantly less in ADR+MR1 animals compared to ADR+IgG animals. In vitro, CD154 blockade significantly attenuated upregulation of CCL2 gene expression by RTEC stimulated by activated macrophage-conditioned medium. In contrast, platelet-induced upregulation of macrophage and mesangial cell proinflammatory cytokine gene expression were not CD154-dependent. CONCLUSION: CD40-CD154 blockade has a significant innate renoprotective effect in ADR nephrosis. This is potentially due to inhibition of macrophage-derived soluble CD154.