ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose of reviewCurrent guidelines on dialysis adequacy for patients with acute renal failure are based upon extrapolation from end-stage renal disease. As a result, intermittent haemodialysis - the most commonly used modality of renal replacement therapy - is typically prescribed for 3 or 4 h three or more times per week. Recent data suggest that alternate day dialysis provides inadequate dialysis dosing in the majority of critically ill patients.Recent findingsMeasurements of urea kinetic modelling show that the delivered dose of dialysis is 20-30% lower than the prescribed dose and even less than adequate for a stable end-stage renal disease patient receiving haemodialysis three times per week. A recently published prospective comparison of two dialysis intensities (alternate day versus daily) demonstrated an association between increased treatment dose and improved outcome in critically ill patients. The beneficial effects of daily dialysis could be explained by lower uraemic toxicity, less fluid overload and a shorter duration of severe acute renal failure.SummaryThe limited data on the effects of dialysis dose on acute renal failure suggest that the relationship between acute renal failure comorbid conditions and death in critically ill patients is more complicated than generally recognized. There is no doubt that alternate day dialysis provides a suboptimal dose of dialysis with negative impact on the outcome. Significant differences render the use of most urea kinetic modelling equations problematic. Despite the current lack of further information we would recommend that haemodialysis should be dosed daily in many cases of hypercatabolic or anuric acute renal failure.

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose of reviewThe focus of the review is to delineate protocols for catheter removal, catheter replacement and duration of therapy when a catheter-related infection occurs, and to demonstrate possible means of preventing such infections.Recent findingsThe evidence supporting these views will be discussed in the light of our current practice.SummaryCuffed tunneled hemodialysis catheters have evolved for wide use as both temporary and semi-permanent hemodialysis access. The primary barriers to long-term catheter use are catheter-related infection and catheter dysfunction. Catheter-related infection has emerged as the primary barrier to long-term catheter use. Under both circumstances, however, catheter replacement or some form of intervention is often needed. Because of this, catheters are often removed and replaced, but the duration of therapy and the timing of replacement of these catheters is not completely clear.

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose of reviewThis review examines recent developments in the understanding of the effect of conventional, bioincompatible peritoneal dialysis fluids on structural and functional changes in the peritoneal membrane. Emphasis is placed on the clinically relevant outcome of failure of long-term peritoneal dialysis. Therapeutic strategies to prevent technique failure, including the use of new peritoneal dialysis fluids and continuous flow peritoneal dialysis, are explored.Recent findingsLong-term (greater than 6 months) exposure to new peritoneal dialysis fluids with physiologic pH, lower lactate concentrations, or lower concentrations of glucose degradation products results in improved leukocyte cytokine release, ultrafiltration, and mesothelial cell mass, respectively. Continuous flow peritoneal dialysis allows efficient small molecule removal using dialysate with lower glucose concentration and possibly less glucose degradation products. Recent technical advances include creation of a double-lumen peritoneal dialysis catheter, and methods of monitoring intra-abdominal pressure and ultrafiltration.SummaryThough initial reports with biocompatible peritoneal dialysis fluids are promising, the efficacy of these new solutions in preventing long-term peritoneal dialysis failure is unproven. Conditions in which new peritoneal dialysis fluids may be beneficial are suggested. Continuous flow peritoneal dialysis requires substantial technical improvements before this technique can be widely accepted.

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

There has been a necessary change in attitude to transplantation; there is much less concern with short-term outcome and more concern with long-term kidney function, overall health and quality of life. Nephrotoxicity is an invariable consequence of long-term treatment with calcineurin antagonists and it is one of the most underestimated causes of late graft loss; it has been reported as a serious threat to both patient and graft survival following heart, liver and bone marrow transplantation. Sirolimus has been shown in many recent studies to be of great value in allowing patients to be weaned from cyclosporine with excellent patient and graft survival at 24 months a signficant improvement in renal function with resolution of hirsutism and gum hyperplasia. Patients maintained on the combined regime of cyclosporine and sirolimus had signifcantly higher blood pressure, much more cyclosporine nephrotoxicity and hyperuricaemia at 12 months. The experimental studies have found cyclosporine and sirolimus potentiate with each other's good and adverse effects. Cyclosporine therefore augments hyperlipidaemia caused by sirolimus, and sirolimus augments nephrotoxicity caused by cyclosporine. The results of these studies indicate that sirolimus is a suitable replacement for cyclosporine or tacrolimus for long-term maintenance therapy. By contrast the use of sirolimus in combination with cyclosporine results in potentiation of side effects. The principal disadvantages being increased cyclosporine associated nephrotoxicity and sirolimus associated hyperlipidaemia

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose of reviewEvidence from several transplant centers indicates that a substantial proportion of acute and chronic renal allograft rejection is caused by antibodies to donor antigens. Antibody-mediated injury arises despite potent anti-T cell pharmacological agents, and probably requires different therapy.Recent findingsAcute humoral rejection occurs in 20-30% of acute rejection cases, has a poorer prognosis than cellular rejection, and is refractory to conventional immunosuppressive therapy. C4d deposition in peritubular capillaries of renal allografts has been demonstrated to be a sensitive and diagnostic in-situ marker of acute humoral rejection that correlates strongly with the presence of circulating donor-specific antibodies. Biopsies with chronic allograft arteriopathy or glomerulopathy also have a high frequency of C4d deposition and donor-specific antibodies. The vessels of other organs, notably the heart, can also be targets of humoral rejection. New polyclonal C4d antibodies work in paraffin sections. Pitfalls in C4d staining have been identified and must be considered in the valid interpretation of results.SummaryAs the histology is variable, the current diagnosis of humoral rejection in biopsies relies on the demonstration of C4d, a component of the classical complement pathway, in peritubular capillaries. The new classification of renal allograft rejection incorporates humoral and cellular mechanisms of injury, with the diagnostic criteria of each. This should prove useful in guiding clinical treatment, and stratifying drug trials, replacing obsolete terms such as ‘vascular rejection’. Specific therapeutic strategies for humoral rejection with controlled trials targeting the humoral limb of immunosuppression are needed.

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose of reviewInadequate cyclosporine exposure is a key risk factor for acute rejection, and may contribute to the development of chronic rejection and graft failure. Pre-dose monitoring does not accurately measure drug exposure because of extensive inter- and intra-patient variability in cyclosporine absorption and metabolism. Limited sampling, using individual timed specimens, offers a new, simple and accurate alternative for clinical monitoring of cyclosporine.Recent findingsThe area under the first 4 h of the concentration-time curve (AUC0-4) and the single-point concentration at 2 h post-dose (C2) are key measures of cyclosporine exposure. De novo studies show that achieving an AUC0-4value of more than 4400 μg.h/l or a C2 level of 1500-2000 μg/l during the first 5 days post-transplant minimizes the risk of rejection and improves graft function. Maintenance studies suggest that reducing the C2 level to approximately 800 μg/l after 3-6 months may improve the serum creatinine level, blood pressure, general well-being and reduce adverse effects.SummarySingle-point C2 monitoring can be implemented quickly and simply with appropriate site and patient training. The timing of phlebotomy is more critical, but immunoassay bias is lower with 2 h post-dose than with trough level measures. Single-point C2 monitoring may be effective in liver and heart replacement, but initial target levels for liver transplantation are lower because cyclosporine is transported directly to the liver via the portal system. C2 monitoring is now being widely adopted as an accurate and practical measure of drug exopsure, and can be combined with pharmacodynamic methods to optimize immunosuppression.

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose of reviewAs epidemiological and clinical studies have shown that damage of large arteries is a major contributory factor to the high cardiovascular morbidity of patients with end-stage renal disease, such a population is particularly appropriate for analysis the impact of arterial stiffness on cardiovascular risk assessment and reduction strategies.Recent findingsAortic pulse wave velocity, a marker of aortic stiffness, has been shown to be a strong independent predictor of cardiovascular and all-cause mortality in patients with end-stage renal disease on hemodialysis. Local arterial stiffness assessment, namely carotid distensibility was also shown to predict cardiovascular risk, both in end-stage renal disease patients and in renal transplant recipients. Furthermore, it was shown in a therapeutic trial that the lack of aortic pulse wave velocity attenuation, despite significant drug-induced reduction in mean blood pressure, was a significant predictor of cardiovascular death in subjects with end-stage renal disease. These results support the hypothesis that measurement of aortic pulse wave velocity could help, not only in risk assessment strategies, but also in risk reduction strategies by monitoring arterial stiffness under different pharmacological regimens. The drug-related reduction of aortic pulse wave velocity could then give prognostic information, in addition to blood pressure reduction.SummaryAortic stiffness measurements could serve as an important tool in identifying end-stage renal disease patients at higher risk of cardiovascular disease. The ability to identify these patients would lead to better risk stratification and earlier and more cost-effective preventive therapy.

ISSN:1062-4821    

出版商:OVID    

年代:2002

数据来源: OVID