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Background: Approximately 25% of haemodialysis (HD) patients use catheters as vascular access. Catheter-related bloodstream infections (CRBSI) are a major risk in this population. The objective of our study was to determine whether endoluminal catheter colonization (ECC) predicts CRBSI., Methods: We followed up a cohort of HD patients in our institution who underwent HD with tunnelled cuffed central venous catheters (TCC) between December 2006 and June 2008. Colonization of the inner catheter lumen was assessed every 15 days immediately before HD by culture of blood-heparin mixture and the time to positivity (TTP) was recorded by the BacT/Alert automated system. CRBSI was confirmed by differential TTP (> 2 h) between TCC and peripheral blood cultures., Results: We studied 51 patients who required 64 TCC. The incidence of CRBSI was 1.65 episodes per 1000 catheter-days, with Staphylococcus epidermidis being the most common cause of infection (76.2%). ECC was more frequent in the CRSBI group than in the non-CRBSI group (100 vs 5.4%, P < 0.001). For S. epidermidis CRBSIs, the median time from ECC to CRBSI was 31.5 days (interquartile range, 27.0-79.0). The sensitivity, specificity and negative and positive predictive values of arterial lumen cultures for S. epidermidis CRBSIs were 100, 96.3, 92.3 and 100%, respectively, while for venous culture, these values were 92.3, 96.3, 92.3 and 96.3%, respectively. For predicting S. epidermidis CRBSI, endoluminal cultures with a TTP of ≤ 14 h had sensitivity and specificity of 52.1 and 97.7%, respectively., Conclusions: This study shows that ECC may predict the risk of developing CRSBI. Surveillance cultures could, therefore, be used to triage individual HD patients who might benefit from specific intervention measures.

Lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic and cardiovascular complications in the general population and in hemodialysis patients. Increased Lp(a) levels have been also described as a possible predictor of vascular access occlusion in patients on chronic hemodialysis. We have studied prospectively the relationship between vascular access survival and Lp(a) levels in 40 hemodialysis patients. The Lp(a) plasma concentrations were measured by enzyme-linked immunosorbent assay in all patients in April 1993. Throughout the following year, evolution and survival of their vascular accesses were analyzed. Failure of vascular access was established when there were complications requiring surgical repair or transluminal angioplasty. Fourteen patients showed failure of vascular access, and the cumulative survival of vascular accesses after 1 year of follow-up was 63.8%. The Lp(a) levels were higher in patients with failure of vascular access than in the others (35.2 +/- 31 vs. 22.4 +/- 25 md/dl), but this difference did not reach statistical significance (p = 0.064). The vascular access survival in patients with Lp(a) levels > 75th percentile (52.5 mg/dl) was significantly lower than in the remaining patients (40 vs. 72%; p = 0.045). This difference increased when we analyzed the patients with Lp(a) levels > 90th percentile (76 md/dl; 25 vs. 68%; p = 0.002). Our results suggest that patients with the highest levels of Lp(a) are at risk of developing complications in their vascular accesses, and they also have lower vascular access survival.

Accidental hypothermia is defined as a spontaneous decrease in core temperature to 35 degrees C or below. Several techniques of active core rewarming have been described. We present the case of a 34-year-old man with severe hypothermia (27 degrees C) caused by cold environment exposure and barbiturate intoxication treated with general supportive measures and active core rewarming with hemodialysis. Core temperature increased by 2.15 degrees C/h with hemodialysis and became normal in 4 h. The clinical situation clearly improved during the hemodialysis session and the patient recovered without any defect. Hemodialysis is a rapid and effective treatment for accidental hypothermia.

Hepatitis B is a frequent complication in haemodialysis patients because of their repeated exposure to blood products, and their impaired cellular and humoral response; trials with plasma-derived hepatitis B vaccine (PDV) show lower immune responses than those in healthy adults. Using a yeast-derived hepatitis B vaccine (YDV), the immunogenicity of two different dose levels (20 and 40 micrograms) and three vaccination schedules were compared in over 270 seronegative dialysis patients. Vaccination with 40 micrograms gave slightly better results than with the 20 micrograms dose. Seroconversion rates were higher with four dose, 40 micrograms vaccination schedules than a three dose schedule, and ranged from 80 to 86%. As the 40 micrograms, 0, 1, 2, 6 month schedule leads to a more rapid rise in antibody levels than the 40 micrograms, 0, 1, 2, 12 month schedule, it appears to be the most appropriate schedule in this patient group.

In a multicenter study of hemodialysis patients in Spain, the immunogenicity of a yeast-derived recombinant deoxyribonucleic acid hepatitis B vaccine was evaluated. Two different vaccination schedules were examined: zero, one, two, six months and zero, one, two, 12 months. Two different dose levels (20 micrograms and 40 micrograms) were also compared. No serious adverse effects were reported by any of the vaccinees; the most frequently reported reaction was soreness at the injection site. This study also indicated that higher concentrations of antibodies are attained when more frequent doses of vaccine are administered. The yeast-derived vaccine produced an immune response similar to that of the plasma-derived vaccines.

In a retrospective study we have examined 20 liver specimens from haemodialysis patients with a mean time on treatment of 27 months. Thirteen specimens were biopsies, the remaining came from autopsies. The presence of refractile particles was found in 55 per cent of biopsies and 100 per cent of autopsies. Its presence was not constantly associated with morphological lesions of the liver. We believe that the deposition of this material could be a fortuitous finding with uncertain clinical implications.

16 chronic haemodialysis patients (group I), with non-microcytic anaemia (mean haemoglobin 7.2 g/dl, SD 1.0, range 5.8-9.8), moderate aluminium overload (serum aluminium 44 micrograms/l, SD 16, range 21-74), and normal or high iron stores (ferritin 800 micrograms/l SD 464, range 34-2013) were treated with intravenous desferrioxamine 1 g at the end of each dialysis for six months. 8 patients with similar characteristics served as controls (group II). After six months group I showed a rise in haemoglobin to 9.1 (SD 2.5) g/dl and a decrease in blood transfusion requirements, both significant, whereas group II showed no changes. Other significant changes observed in group I, but not group II, were a rise in reticulocytes and in red cell creatine and a fall in red cell protoporphyrin and serum ferritin. Ferritin decreased more in the patients whose anaemia improved. Minor increases in serum aluminium in group I did not differ from those in the control group. Desferrioxamine may benefit the anaemia of chronic haemodialysis patients through improvement of erythropoiesis. The effect seems not to be related to chelation of a heavy aluminium overload.