The International Quotidian Dialysis Registry: annual report 2006

Interest in short daily and nocturnal hemodialysis (HD) regimens continues to grow worldwide. Despite growing optimism that these therapies will afford better patient outcomes over conventional HD, the current literature has not been viewed as sufficiently compelling to affect widespread implementation in most jurisdictions. Before these therapies can gain wider acceptance, larger and more rigorous studies will likely be needed. In June 2004, the Quotidian Dialysis Registry, based at the Lawson Health Research Institute at the University of Western Ontario, Canada, began recruiting patients across North America. By using an Internet-based data entry platform, patients from various centers worldwide will eventually be recruited, and studied prospectively. This paper constitutes the second annual update on patient and center recruitment, patient and treatment characteristics, and future directions for the registry.     

Modality options for renal replacement therapy: the integrated care concept revisited

As the End-stage renal disease population continues to grow, innovative strategies that optimize patient outcomes while capitalizing on the relative strengths of the existing modalities must be sought. Renal transplantation remains the preferred form of renal replacement therapy, but given the limited supply of donor organs, dialytic therapies will continue to constitute a large part of the modality mix. Matching patients to the most suitable modalities requires that a number of factors be considered. These include the patient's autonomy, medical and social factors, system-related issues, patient outcomes, and finances. While peritoneal dialysis and hemodialysis (HD) have traditionally been viewed as competing modalities, we propose that they, along with home and frequent HD regimens, may be used in a complementary manner, which is based on current evidence, and may provide optimal outcomes while containing treatment costs. In this review, we attempt to synthesize the current literature describing the various issues that affect modality selection, and offer an approach to achieving a balance between these many competing factors.     

The International Quotidian Dialysis Registry: annual report 2005

The International Quotidian Dialysis Registry was designed to collect data describing treatments, characteristics, and outcomes of patients treated with quotidian hemodialysis (HD) worldwide. In July 2004, North American centers were first invited to enroll patients. By March 1, 2005, a total of 70 nocturnal and 8 short-daily HD patients from three Canadian and two US centers were enrolled. As recruitment continues, projected enrollment for 2005 may exceed 200 patients from North America alone. Preliminary analyses indicate that the current registry cohort is younger (mean age, 49.5 +/- 1.6 years) and carries a lower burden of comorbidity than the overall North American HD population. The low event rate expected in this cohort underlines the need for a large sample size if an appropriately powered survival study is to be undertaken. Increasing recruitment in the United States by including HD centers owned or managed by large dialysis organizations, and beginning overseas collaborations to include Australia, New Zealand, Europe, and South America will be the primary areas of focus for 2005.     

The International Quotidian Hemodialysis Registry: rationale and challenges

Outcomes from conventional thrice-weekly hemodialysis (CHD) are disappointing for a life-saving therapy. The results of the HEMO Study show that the recommended minimum dose (Kt/V) for adequacy is also the optimum attainable with CHD. Interest is therefore turning to alternative therapies exploring the effects of increased frequency and time of hemodialysis (HD) treatment. The National Institutes of Health have sponsored 2 randomized prospective trials comparing short hours daily in-center HD and long hours slow nightly home HD with CHD. An International Registry has also been created to capture observational data on patients receiving short hours daily in-center HD, long hours slow nightly home HD, and other alternative therapies. Participation by individual centers, other registries and the major dialysis chains is growing and currently data from nearly 3000 patients have been collected. Pitfalls in data collection have been identified and are being corrected. A matched cohort (patients in other registries) study is planned to obtain information regarding hard outcomes expected from these therapies. The Registry may become the most important source of information required by governments, providers, and the nephrological community in assessing the utility of such therapies.     

Hemodynamic and Volume Changes during Hemodialysis

Background: Volume overload is a factor in the hypertension of hemodialysis (HD) patients. Fluid removal is therefore integral to the hemodialysis treatment. Fluid removal by hemodialysis ultrafiltration (UF) may cause intradialytic hypotension and leg cramps. Understanding blood pressure (BP) and volume changes during UF may eliminate intradialytic hypotension and cramps. Studies (S1, S2, and S3) were carried out to determine the amount and direction of changes in body fluid compartments following UF and to determine the relationships between BP, changes in blood volume (ΔBV), central blood volume (CBV), cardiac output (CO), peripheral vascular resistance (PVR) plus total body water (TBW), and intra‐ and extracellular fluid volumes (ICF, ECF) in both the whole body and body segments (arms, legs, trunk). Methods: Indicator dilution technology (Transonic) was used for CBV, CO, and PVR; hematocrit monitoring (Crit‐Line) was used for ΔBV segmental bioimpedance (Xitron) for TBW, ICF, and ECF. Results: S1 (n = 21) showed UF sufficient to cause ΔBV of ?7% and lead to minor changes (same direction) in CBV and CO, and with cessation of UF, vascular refilling was preferential to CBV. S2 (n = 20) showed that predialysis HD patients are ECF‐expanded (ECF/ICF ratio = 0.96, controls = 0.74 [P < 0.0001]) and BP correlates with ECF (r = 0.47, P = 0.35). UF to cause ΔBV of ?7% was associated with a decrease in ECF (P < 0.0001) and BP directly (r = 0.46, P = 0.04) plus ΔBV indirectly (r = ?0.5, P = 0.024) correlated with PVR, while CBV and CO were maintained. S3 (n = 11) showed that following UF, total‐body ECF changes were correlated with leg ECF (r = 0.94) and arm ECF (r = 0.72) but not trunk ECF. Absolute ECF reduction was greatest from the legs. Conclusions: Predialysis ECF influences BP and UF reduces ΔBV and ECF, but CBV and BP are conserved by increasing PVR. ECF reduction is mainly from the legs, hence may cause cramps. Intradialytic hypotension is caused by failure of PVR response.     

International quotidian dialysis registry: Annual report 2009

The International Quotidian Dialysis Registry (IQDR) is a global initiative designed to study practices and outcomes associated with the use of hemodialysis regimens of increased frequency and/or duration. Several small studies suggest that compared with conventional hemodialysis (HD), short-daily, nocturnal, and long conventional HD regimens may improve surrogate endpoints and quality of life. However, methodologically robust comparisons on hard outcomes are sorely lacking. The IQDR represents the first-ever attempt to aggregate long-term follow-up data from centers utilizing alternative HD regimens worldwide, and will have adequate statistical power to examine the effects of these regimens on multiple clinical endpoints, including mortality. To date, the IQDR has enrolled patients from Canada, the United States, Australia, and New Zealand, with plans in place to begin linking with additional commercial databases and national registries. This fifth annual report of the IQDR describes (1) a proposed governance structure that will facilitate international collaboration, stakeholder input and funding; (2) data sources and participating registries; (3) recruitment to date and patient baseline characteristics; and (4) an agenda for future research.     

Experimental Analysis of Mechanical Behavior of Lintels with Murfor Reinforcement in Structural Masonry

The main goal of this study is analysis the mechanical behavior, failure mode and deflections of masonry beams lintels when subjected to concentrated loading. Walls were built using hollow clay blocks, using horizontal reinforcement on bed joint, and using of Murfor steel reinforcement. The conclusions of this work was： at middle of span, the load and displacement results present a linear behavior until failure; there two regions of failure, the region ＂A＂ presents the association of crushing and the region ＂B＂ shows the shear stress between block and mortar; the visual analysis of experimental tests shows the lost of adhesion between the mortar joint and blocks. It was not observed cracks on the mid-span produced by bending; it is possible to detach that the use of plane truss in Brazil as technological alternative is feasible and makes the masonry walls execution more rational, increasing the velocity of production.