Complications of vascular access in hemodialysis (HD)--aged vs adult patients.

Reports on the success of permanent vascular access in elderly HD patients vary considerably. We reviewed the records of 149 patients [62F and 87M] aged 20-89 years old (median 59) who were on hemodialysis for 6-242 (49 median) months, and had undergone 202 vascular access procedures (177 Cimmino-Brescia fistulae and 25 PTFE grafts). Patients were divided into two groups according to the age they started HD. Group A: 48 patients, over 60 years old (range 60-83; median 70) on HD for 43.5, (6-140) months. Group B: 101 patients, under 60 years old, range (15-59) median 46, on HD for 54 (6-242) months. There were no differences between the two groups in terms of gender, primary renal disease, (except polycystic kidney disease), Hct and EPO administration. The initial choice of vascular access, the complications and the technique survival were examined in both groups. Cimmino-Brescia fistulae were used as the first choice of vascular access in all patients except one in group B. PTFE-grafts were the second or third choice in 7/48 (group A) and 15/101 (group B) (p: NS). The only reason for technique failure was vascular thrombosis in both groups (11/48 group A and 31/101 group B p: NS). Other complications were: aneurysms (10/48 and 14/101, p: NS), infections (0/48 and 2/101 p: NS) and edema (0/48 and 6/101, p: NS). Five-year technique survival of the first AV fistula in the two groups was 35% and 45% respectively (log-rank test, p: NS). These findings suggest that: a) A.V. fistula is the first choice of vascular access in aged HD patients; b) There is no difference in vascular access complications across age groups; c) Survival of the first A.V. fistula is independent of age.

Hepatitis E virus (HEV) infection in haemodialysis patients. The Multicentre Haemodialysis Cohort Study on Viral Hepatitis.

BACKGROUND: The aim of this study was to determine the prevalence of hepatitis E virus (HEV) infection among patients undergoing haemodialysis (HD) and to evaluate whether chronic haemodialysis is associated with an increased risk of HEV infection. METHODS: Serum samples from 420 HD patients and 316 healthy volunteers were tested for IgG and IgM antibodies to HEV (anti-HEV). Anti-HEV IgG positive sera were confirmed using synthetic peptides. RESULTS: Anti-HEV IgG was confirmed in 27/420 (6.4%) of the HD patients and in 7/316 (2. 2%) of the reference group (P=0.07). However, multiple logistic regression analysis showed that the prevalence of anti-HEV IgG was not significantly higher in HD patients compared with the reference group, after controlling for age and sex. No patient was found positive for anti-HEV IgM. The presence of anti-HEV was associated with sex in HD patients (P=0.04). No significant association was found between anti-HEV and underlying renal disease, anti-HCV, anti-HBc, blood transfusions, history of elevated transaminases, history of clinical hepatitis and renal transplantation. A marginal association, which was observed with the duration of haemodialysis in univariate analysis (P=0.07), was not confirmed in multivariate analysis. CONCLUSIONS: Chronic haemodialysis is not associated with an increased risk of exposure to HEV, and the high prevalence of anti-HEV IgG in HD patients reported in uncontrolled studies is possibly due to the confounding effect of age and sex.

The influence of parathyroid hormone on platelet-activating factor (PAF) blood levels in hemodialysis patients.

PAF represents a new family of glycerophospholipids and possesses multiple biological activities including platelet aggregation. Production of PAF has been demonstrated in a number of different cell types and in response to various stimuli. In this work an attempt is made to study the effect of parathyroid hormone (PTH) on PAF production. In 13 hemodialysis patients with severe secondary hyperparathyroidism, PAF levels in blood as well as intact PTH (iPTH) and total calcium in serum (tCa), before and 10 days after parathyroidectomy (PTHx), were measured. Our results indicate that PAF levels in blood as well as iPTH and tCa were higher before PTHx than after [a) PAF before 1.10 x 10(-4) +/- 9 x 10(-5) gamma/ml and after 2 x 10(-5) +/- 1 x 10(-5) gamma/ml, p < 0.001; b) iPTH before 880 +/- 392.9 pm/ml and after 121.6 +/- 61.9 pm/ml, p < 0.001; c) tCa before 9.96 +/- 0.35 mg/dl and after 8.38 +/- 0.30 mg/dl, p < 0.001]. Using stepwise regression analysis it seems that PAF is dependent on calcium which is dependent mainly on iPTH. Since a) platelet dysfunction is among the factors which are incriminated for bleeding in uremia and b) PAF which induces platelet aggregation acts via specific receptors, we checked the response of platelets in terms of their ability to aggregate in vitro following increasing doses of exogenous PAF in 5 of the above patients in order to investigate whether the high levels of PAF before PTHx may desensitize platelets.(ABSTRACT TRUNCATED AT 250 WORDS)