[Central vascular access: rational and results]. / I cateteri venosi centrali modello Tesio: razionale e risultati.

Central venous catheterization for hemodialysis using double cannula has become the preferred central vascular form in acute cases. Moreover, in chronic cases, this form of vascular access has replaced the internal arterio-venous fistula whenever the latter is difficult to realize, or when patient's cardio-circulatory condition would discourage its creation. The central vascular access presents frequent complications, compromising their efficiency and duration. Tesio's central venous catheters were thoroughly studied and manufactured to overcome these complications, allowing a long life span of the vascular access. In this study 108 patients with Tesio's internal jugular central venous catheters were followed-up in the period 1990 to 1994. All patients underwent hemodialysis in Pordenone Center. Central venous access survival fluctuated between 93% and 82% in the first year and the fifth year respectively. However, access survival dropped to 32% after seven years. The accurate choice of the catheters' manufacturing material as well as the correct technical positioning has determined a significant increase in the vascular access survival, thanks to the important decrease in prevalence and seriousness of complications. We believe that the decreased accuracy in catheter management over time is the major cause of delayed loss of the central vascular access.

Hepatitis C virus risk: a hepatitis C virus related syndrome.

BACKGROUND: The association between mixed cryoglobulinemia (MC) and hepatitis C virus (HCV) infection has been recently described in many reports. OBJECTIVE: The aim of this study was to evaluate the long-term prognosis of hepatitis C virus-positive patients affected by mixed cryoglobulinemia with or without kidney involvement. PATIENTS: At total of 119 hepatitis C virus-positive patients affected by mixed cryoglobulinemia were divided in two groups. Group A: mixed cryoglobulinemia without kidney involvement (103 cases); group B: mixed cryoglobulinemia with glomerulonephritis (GN) (16 cases). A further 37 patients affected by mesangio-proliferative glomerulonephritis (MPGN) were evaluated as controls (group C). METHODS: Anti-hepatitis C virus antibodies were determined by commercial kits and hepatitis C virus-RNA was detected by polymerase chain reaction (PCR) amplification of the 5' untranslated region (5'UTR) of the virus. The hepatitis C virus genotype was determined according to Okamoto. Liver biopsy was performed in 62 patients, bone marrow biopsy in 65 patients, and kidney biopsy in all patients with proteinuria. RESULTS: In group A, 46 patients (45%) were affected by chronic liver disease (CLD), 21 (20%) by low-grade non-Hodgkin's lymphoma (NHL) and 16 (15%) by both diseases. All patients of group B were affected by type I membrano-proliferative glomerulonephritis, 3 (19%) by chronic liver disease, 6 (37%) by low-grade non-Hodgkin's lymphoma, and 7 (44%) by both diseases. Several genotypes of hepatitis C virus were found, but Type 1b was prevalent. In group C, no patient showed chronic liver disease or non-Hodgkin's lymphoma. Younger age, higher mean blood pressure, lower C4 serum level, and poorer survival significantly distinguished group B from group A. Survival rates at 5 years were: 87.4% for group A, 89.5% for group C, and 50.0% for group B. None of the patients of group B developed kidney failure requiring dialysis, whilst infections were the leading cause of death. CONCLUSIONS: In hepatitis C virus-positive patients, the presence of mixed cryoglobulinemia associated with kidney involvement seems to indicate a new syndrome characterized by immune system impairment, lack of progression to kidney failure, and poor survival (hepatitis C virus-Risk syndrome).

Menopause, menstrual and reproductive history, and bone density in northern Italy.

STUDY OBJECTIVE: To analyse the relationship between menstrual and reproductive factors and the risk of low bone mineral density (BMD). DESIGN: This was a population based screening programme carried out between 1991 and 1993 among 1373 perimenopausal women in northern Italy by means of dual photon absorptiometry at the lumbar spine. MAIN RESULTS: BMD was strongly related to the age at menopause. In comparison with women reporting menopause below 45 years of age, the odds ratios (OR) of being in the lowest compared with the highest BMD tertile were 0.7 (95% confidence interval (CI) 0.3,1.5) and 0.3 (95% CI 0.1,0.8), respectively, in those with menopause at age 45-49 and above 50 years: the trend in risk was significant. Likewise, the risk of being in the lowest tertile increased with years since the menopause. Compared with women who reported they had undergone the menopause less than two years before interview, the OR of being in the lowest BMD tertile were 2.1 (95% CI 1.1,4.3), 2.3 (95% CI 1.1, 5.0), and 5.7 (95% CI 2.5,12.9) respectively in women who reported menopause 2-5, 6-9, and > or = 10 years earlier. The protective effect on bone density of late age at menopause was observed in different strata of years since menopause. Likewise, the increasing risk of a low BMD with increasing years since the menopause was evident in strata of different age at menopause. No relationships were observed between BMD and the age at menarche, characteristics of menstrual cycles, and the duration of menses. Likewise, no association emerged between reproductive history, including parity and age at first pregnancy, and BMD. CONCLUSIONS: In this Italian population the risk of being in the lowest BMD tertile decreased with increasing age at menopause and increased with years since menopause. No relationships emerged between BMD and other menstrual characteristics or reproductive factors.

Double catheterization of the internal jugular vein for hemodialysis: indications, techniques, and clinical results.

Central vascular catheters are used to access the central vascular system in both acute and chronic uremic patients undergoing hemodialysis. Among different approaches, the internal jugular vein seems to have less adverse effects. We describe our long-term experience with a two-catheter system. Percutaneous jugular vein cannulation was performed using Medcomp silicone rubber catheters. The study included 108 patients undergoing hemodialysis. One- and 2-year survival was 93 and 91%, respectively; 36 died because of unrelated causes. Blood flow rate was 284 mL/min; venous pressure at 1 year was 90 mm Hg. Complications included accidental withdrawal (6), dysfunction (4), catheter clotting (11), mediastinal hematoma (2), pneumothorax (1), and sepsis (7). Good long-term survival and a low complication rate make this system a safe and reliable method of access for long-term hemodialysis.

Does continuous ambulatory peritoneal dialysis induce hypercholesterolemia?

Hypercholesterolemia has been recognized as a significant risk factor for atherosclerosis and coronary artery disease. The aim of this study was to evaluate the prevalence of hypercholesterolemia and the role, if any, of type of dialysis. In 19 hemodialysis (HD) and 20 continuous ambulatory peritoneal dialysis (CAPD) subjects, body weight, body mass index (BMI), arm muscle area (AMA), total cholesterol (C), HDL and LDL fractions, triglycerides, C/HDL ratio, glycosylated hemoglobin, and apolipoproteins AI, AII, B, CII, CIII, and E were evaluated. Hypercholesterolemia was defined as cholesterol greater than 220 mg/dL and LDL greater than 150 mg/dL. Body weight, body mass index, and arm muscle area were higher (p < 0.05) in CAPD as compared with HD; so were total cholesterol, LDL, C/HDL ratio, and glycosylated hemoglobin (Hbalc). Hypercholesterolemia prevalence was 3/19 in HD and 11/20 in CAPD (p < 0.05). A relationship between Hbalc and C/HDL ratio was found in the CAPD group (r = 0.48; p < 0.05). We are greatly concerned about these metabolic effects of CAPD; therefore, we should carefully select patients to be treated by CAPD. Aggressive nutritional and pharmacological treatment for glucose intolerance and hypercholesterolemia in CAPD patients must be performed in order to reduce the incidence of coronary artery disease (CAD).

Efficacy of hepatic computed tomography to detect iron overload in chronic hemodialysis.

The diagnostic efficacy of hepatic computed tomography density (HCTD) in comparison with serum ferritin for the detection of iron overload was investigated in uremic patients on maintenance hemodialysis (HD) and in patients with idiopathic hemochromatosis (IHC). Ten IHC patients, 38 HD patients and 40 healthy subjects underwent the CT scanning of the liver and determination of percent saturation of transferrin, serum ferritin concentration and HLA typing. Liver iron content was determined by histochemical grading and direct measurement of liver iron concentration either in IHC patients or in HD patients. Nineteen HD patients were considered to have iron overload on the basis of liver iron concentration exceeding 3.6 mumol/100 mg dry weight. The mean +/- SD values of HCTD in healthy subjects, IHC patients, HD patients with iron overload and without iron overload were 60.2 +/- 5.6, 79 +/- 5.6, 71.4 +/- 3.6, 58 +/- 3.8 Hounsfield units, respectively. HCTD showed positive correlations with liver iron concentration and serum ferritin either in IHC patients or in HD patients. The analysis of the diagnostic efficacy of HCTD in comparison with serum ferritin for the detection of excessive hepatic iron in HD patients demonstrated that HCTD had higher sensitivity, specificity, positive and negative predictive values. Cut-off points were arbitrarily fixed to 66 Hounsfield units for HCTD, 400 micrograms/liter for serum ferritin and 3.6 mumol/100 mg dry weight for liver iron concentration. Seventeen HD patients who possessed the histocompatibility antigens associated with IHC, namely HLA-A3 and/or HLA-B7 and/or HLA-B14, had liver iron concentration, serum ferritin and HCTD values higher than those of the HD patients without these "hemochromatosis alleles".(ABSTRACT TRUNCATED AT 250 WORDS)

Fusarium peritonitis in peritoneal dialysis: report of two cases.

This report describes two cases of peritoneal dialysis-related peritonitis caused by Fusarium species which have been incriminated in a variety of disease conditions. Treatment with 5-Fluorocytosine was unsuccessful, but removal of the catheter resulted in a rapid resolution of the infections.

Source and route of microbial colonisation of parenteral nutrition catheters.

To assess the effectiveness of tunnelling the polyurethane venous catheter for parenteral nutrition in reducing the frequency of catheter microbial colonisation, and to investigate the routes taken by microorganisms colonising the central venous catheter, 109 patients were randomised to traditional subclavian catheterisation (58, group A) or to subcutaneous catheter tunnelling (51, group B). Samples were taken from patients and their nurse attendants to identify their indigenous flora. Cultures were also done of swabs from the catheter insertion site, blood, nutrient solution, segment of the catheter, and washings of the catheter hub. Intravascular segment colonisation was commoner in group A (18/58) than in group B patients (4/51), and bacterial migration from insertion site to intravascular segment was also commoner among group A (9/58) than among group B patients (1/51). Catheter hub contamination was responsible in 10 out of 22 cases of microbial colonisation; in 6 of these 10 the bacterium isolated was present on the skin of nurses who changed the bag. Contamination of the insertion site skin and of the CVC hub were equally responsible for the microbial colonisation of the intravenous segment of the catheter.

Dialysis for the elderly: survival and risk factors.

We evaluated survival and risk factors in 86 elderly patients (pts) who underwent dialysis at one center throughout the last 10 years. Thirty-five pts received hemodialysis (HD), 32 intermittent peritoneal dialysis (IPD), and 19 continuous peritoneal dialysis (CAPD). Risk factors included: treatment, age, sex, underlying disease, heart failure (HF), peripheral vascular disease (PVD), diabetes mellitus (DM) and malignancy. Median age was 65 years for both HD and CAPD, and 69 for IPD (p less than 0.05). Survival evaluation demonstrated a longer life span for HD vs. IPD (p = 0.02) for CAPD vs. IPD (p = 0.03) and no difference between HD and CAPD pts. Cox analysis showed higher death odds ratio (OR = 2.4) for IPD vs. HD and lower ratio for CAPD vs. IPD (OR = 0.3). Other OR positive risk factors were: HF, PVD, DM and malignancy. The median value of risk factors for each group was higher for both IPD and CAPD vs. HD. Both life span and death OR for CAPD were equal to HD in spite of higher risk factors in CAPD group. The lower survival of the IPD group may be due to its older age. CAPD should represent the elective treatment for elderly uremics while HD or IPD should be reserved for selected patients.

Intraocular pressure changes during hemodialysis: prevention of excessive dialytic rise and development of severe metabolic acidosis following acetazolamide therapy.

The response of intraocular pressure (IOP) to hemodialysis was investigated in 55 patients with end-stage kidney disease enrolled in a chronic dialysis program. The mean level of IOP, measured by the Goldman applanation tonometer, before dialysis was slightly lower than that of a control group of 50 healthy subjects (14.9 +/- 2 mm Hg vs 15.6 +/- 1.9 mm Hg. p = .07). During dialysis IOP underwent an excessive rise (7.8 to 12.5 mm Hg) in 10 patients (group 1), remained unchanged (variations below 2 mm Hg) in 41 patients (group 2), and decreased (3.1 to 5.1 mm Hg) in 4 patients (group 3). In group 1 patients, gonioscopy showed a narrow angle between iris and lateral cornea. Conversely, the anterior chamber angle was normal in patients of groups 2 and 3. The effect of a 7-day course of acetazolamide therapy (500 mg per day orally) on IOP was investigated in group 1 patients. Acetazolamide was capable of preventing the excessive IOP rise during dialysis. The mean reduction of such a dialytic rise was 8.1 mm Hg. However, despite this effect, in these patients the IOP level after dialysis still remained significantly higher than that of patients of group 2 (18.1 +/- 1 mm Hg vs 14.9 +/- 0.8 mm Hg. p less than .0001). Acetazolamide therapy precipitated in all patients a severe metabolic acidosis (blood pH fell from 7.38 +/- 0.02 to 7.24 +/- 0.03, p less than .0001; and bicarbonate concentration from 21 +/- 2.5 mmol/liter to 12.3 +/- 2.4 mmol/liter, p less than .0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum reverse T3 assay for predicting glucose intolerance in uremic patients on dialysis therapy.

Sixty patients with end stage chronic renal failure (CRF) enrolled in a dialysis program underwent studies of serum thyroid hormones and carbohydrate metabolic state. The aim of the study was: 1) to evaluate whether the glucose intolerance per se represents a factor for the alteration of circulating thyroid hormones; and 2) to explore the potential usefulness of specific thyroid hormones and particularly reverse T3 (RT3) as indicators for predicting glucose intolerance. Forty-two patients received hemodialysis and 18 were on intermittent peritoneal dialysis (IPD). CRF patients had reduced serum total T4 and T3 levels, slightly decreased RT3 and TBG concentrations and normal TSH values. There was no significant difference in serum thyroid hormone indices between HD and IPD patients. Glucose intolerance was found in 25 patients. Ten had fasting hyperglycemia and diabetic response to oral glucose tolerance test (OGTT), 15 had an impaired glucose tolerance according to the criteria of the National Diabetes Data Group. In CRF patients with glucose intolerance, serum T3 and T3/T4 molar ratio were significantly lower than in those with a normal OGTT response, whereas serum RT3 and RT3/T4 molar ratio were found to be higher. In the whole group of CRF patients these serum thyroid hormones closely correlated with glucose tolerance indices. To investigate the usefulness of serum RT3 assay in predicting glucose intolerance we compared the outcome of the OGTT and serum RT3 values. Using the results of the OGTT as the true diagnosis of glucose intolerance, serum RT3 assay showed a diagnostic specificity of 94.2% and a sensitivity of 100%. In conclusion these results suggest that: 1) the glucose intolerance, which frequently occurs in uremia, may influence circulating thyroid hormones probably leading to a shift in the peripheral tissue conversion of T4 from T3 to RT3; and 2) serum RT3 assay could assume a clinical interest in assessing carbohydrate metabolic state in treated end stage renal failure independently of the type of dialysis therapy.

Reversible tubular dysfunction in alcohol abuse.

The discovery of an unexplained alkaline urine pH in a significant percentage of chronic alcoholic patients prompted us to evaluate some aspects of their tubular function. We studied 60 patients with a history of alcohol consumption of at least 160g daily for 10 years or more. Only patients without clinical and histopathological evidence of chronic liver disease were included in the study. The endogenous creatinine clearance was in the normal range in all patients. On the first day of hospitalisation 22 patients (36.6%) had a urine pH greater than 6.4 and a daily bicarbonate excretion ranging from 5.8 to 25.9mmol. The fractional urinary excretion of beta 2-microglobulin, sodium, potassium, chloride, calcium, phosphorus and uric acid were significantly increased compared with those of 38 alcoholic patients with urine pH less than 6.4 and those of 50 healthy controls. All these indices of tubular function improved during withdrawal, and after 30 days of abstinence their values did not differ from those of controls. This data provides evidence that in one-third of heavy drinkers alcohol abuse causes a complex tubular dysfunction which, at least in this stage of alcoholic disease, recovers with abstinence.

Torulopsis glabrata peritonitis complicating continuous ambulatory peritoneal dialysis: successful management with oral 5-fluorocytosine.

We report two cases of fungal peritonitis caused by Torulopsis glabrata, an uncommon opportunistic pathogen, in patients with end-stage renal disease receiving continuous ambulatory peritoneal dialysis (CAPD). The general clinical characteristic of T glabrata peritonitis was comparable to previously reported cases of Candida peritonitis. Although appropriate therapy of fungal peritonitis in patients undergoing CAPD still remains controversial, both for the drug of choice and for the dosage to be used, our study indicates that a 5-week course of oral 5-fluorocytosine (5-FC) may obviate the need to remove the peritoneal catheter during the management of peritonitis caused by susceptible strains of T glabrata.