Developments towards an artificial kidney

This article reviews the present state of renal failure and its treatment in the industrialized world. Novel and experimental therapies for the treatment of renal failure are covered, with special emphasis on a hybrid bioartificial kidney currently undergoing clinical trials in the USA. Preclinical data, results from human trials and work on miniaturization of the bioartificial kidney for implantation are presented. Research on microfluidics and nanotechnology applied to dialysis is ongoing in many academic centers, and several promising approaches are discussed. After 10 years of incremental improvements in end-stage renal disease care, several revolutionary technologies are on the horizon and approaching the marketplace.

[Corneal opacity in a contact lens wearer on hemodialysis for renal failure]

A 53-year-old contact lens wearer on renal dialysis developed visual impairment due to corneal opacity. The opacity was of a crystalline type and diffusely scattered in the anterior cornea. As oxalosis was suspected ascorbic acid was immediately omitted from the dialysis treatment schedule. Within a few weeks the visual acuity recovered and the corneas became nearly clear. The cornea is an uncommon manifestation site for oxalosis. Nevertheless, one should be aware of this possible sign for oxalosis, which can be a life-threatening complication of treatment with high dose ascorbic acid.

Chapitre B - Insuffisance rénale et vessie neurologique

Historically, impaired renal function was the leading cause of death in spinal cord injury patients. Although the management of these patients has considerably improved due to progress in functional rehabilitation and neurourology, renal failure remains a significant cause of morbidity in this population. In this article, the authors review and classify the diagnostic tools able to detect urological changes likely to induce irreversible impairment of renal function. Based on a review of the recent literature, they define the incidence of renal impairment (morphological or function) in spinal cord injury patients and describe the main risk factors for deterioration of renal function in these patients.

Implications of levels of serum mineral metabolism markers, albumin and C-reactive protein for treatment costs of patients on maintenance dialysis

BACKGROUND

Secondary hyperparathyroidism, malnutrition and inflammation have been reported to associate with adverse outcomes in dialysis patients. However, little is known about the implications of these conditions for treatment costs.

METHODS

The cost data of all adult patients who had entered dialysis therapy at Tampere University Hospital between 1991 and 1996 and had remained on dialysis for at least 1 year were collected. results of measurements of parathyroid hormone (PTH), calcium, phosphorus, albumin and C-reactive protein (CRP) were obtained from the database of the hospital.

RESULTS

Patients (n = 109), aged 57.0 +/- 14.9 years, included 57% men and 37% diabetics; 62% started on hemodialysis and 38% on peritoneal dialysis. Average daily costs were USD 161 (range 95-360). After controlling for patients' age, body mass index, gender, dialysis modality and primary renal disease, there was a positive correlation between average CRP and average costs and a negative correlation between albumin and costs. Correlations between mineral metabolism markers and costs were not found, but there was a trend towards lower cost among patients who achieved the Kidney Disease Outcomes Quality Initiative targets of calcium, phosphorus and PTH (USD 145 +/- 31) compared with those with nonoptimal levels (USD 165 +/- 48; p = 0.095). Costs of patients with at least one in-target PTH measurement were lower than costs of patients with constantly low PTH (USD 148 +/- 31 vs. 170 +/- 48; p = 0.01).

CONCLUSION

Serum levels of albumin and CRP correlated with dialysis patients' treatment costs. Achieving the Kidney Disease Outcomes Quality Initiative targets may be associated with lower costs.

Reduction in platelet activation by citrate anticoagulation does not prevent intradialytic hemodynamic instability

BACKGROUND

The etiology of intradialytic hemodynamic instability is multifactorial. Of the various factors involved, a rise in core temperature seems to be crucial. In this respect, the bioincompatibility of hemodialysis (HD) treatment might play an important role. The application of cool dialysate reduces the number of periods of intradialytic hypotension (IDH) considerably. In rats, roller pump perfusion caused hypotension by shear stress induced platelet aggregation and subsequent serotonin release. During clinical HD, citrate anticoagulation abolished platelet activation almost completely. Hence, citrate anticoagulation might reduce IDH, whereas the beneficial effect of cool dialysate might be partly explained by reduced platelet activation.

METHODS

In the present study, blood pressure, IDH episodes, platelet activation, platelet aggregation, and serotonin release were studied crossover in 10 patients during HD with dalteparin anticoagulation at normal and low dialysate temperatures and during HD with citrate.

RESULTS

Citrate strongly reduced platelet activation, but did not improve IDH. The blood pressure was best preserved during cool-temperature HD, despite manifest platelet activation. Platelet activation was not accompanied by a rise in the plasma serotonin concentration.

CONCLUSIONS

Three major conclusions can be drawn: (1) it is unlikely that platelet activation and subsequent serotonin release underlie IDH in the clinical situation; (2) the protective effects of cool dialysate on IDH appear to be independent of HD-induced platelet activation, and (3) extrapolating results from rat experiments to the human situation requires uppermost prudence.

[Long-term outcomes after acute vitamin D3 intoxication]

We observed 75 subjects with acute vitamin D3 intoxication (AVD3I). The clinical manifestations of this intoxication are kidneys disorders (65.0%), renal insufficiency (51.0%), gastrointestinal tract disorders (23.0%), arterial hypertension (52.0%). After this intoxication these patients are recommended prolonged rehabilitation.

Low-functioning hemodialysis patients improve with exercise training

The Renal Exercise Demonstration Project provided two different approaches to exercise programming to a group of hemodialysis patients. Physical functioning and self-reported health-related quality of life were measured at baseline, after 2 months of independent exercise, and again after 2 months of in-center cycling. This study compares the responses to intervention of patients who initially scored low (<34) on the Physical Component Scale (PCS) on the Medical Outcomes Study Short-Form 36 questionnaire to those who initially scored higher (>34) on the same scale. The high-PCS group scored higher on all physical function tests (normal gait speed, fast gait speed, and sit-to-stand test) at each testing time than the low-PCS group. The high-PCS group improved only on the sit-to-stand test, whereas the low-PCS group improved in all three physical function tests. There were significant differences between the groups in change over time in all the physical scales and the PCS over time, with the low-PCS group showing improvements in response to the intervention and the high-PCS group showing no change over time. No differences in change over time were noted between the groups on the mental scales in either group. We conclude that low-functioning hemodialysis patients can benefit from exercise counseling in both objective measures of physical functioning and self-reported physical functioning. The impact of such interventions seems to be more profound in the lowest functioning patients.

Exercise after renal transplantation

Renal transplant recipients experience troublesome side effects of the immunosuppression medication, many of which may be attenuated or ameliorated with regular physical activity. Preliminary data show that exercise training after transplantation increases exercise capacity and muscle strength and may contribute to higher quality of life after transplantation.

[Dysfunction of the peripheral and autonomic nervous systems in patients on long-term hemodialysis program]

Haemodialysis discloses complex mechanisms leading to the syndrome of biological equilibrium derangement, including dysfunctions of the autonomic, peripheral and central nervous systems. Neurological problems can appear in the patients undergoing haemodialysis treatment as its complications or as a consequence of metabolic disturbances. The degree of involvement of the peripheral nervous system is connected with the duration of dialysis treatment and with certain blood biochemical parameters. Systematic haemodialysis treatment leads to normalization of the changed electrophysiological parameters. Prolonged treatment with repeated haemodialyses increases the activity of the sympathetic nervous system, which manifests itself as increased sensitivity of baroreceptors. An evidence of changes in the vagal nerve system during prolonged haemodialysis treatment is decreased response to atropine. Dysfunction of the autonomic nervous system is rather labile, while peripheral nervous system disturbances are relatively stable and often refractory to therapy with haemodialyses.