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Biomedical subjects

L Piera

Publications and source records attributed to L Piera.

At least 19 recordsLinked to original sources
PubMed2000

The function of permanent vascular access.

BACKGROUND: Complications arising from vascular access (VA) are major causes of morbidity in patients on renal replacement therapy (RRT). They contribute to frustration of health care providers and to high medical cost. To prevent failures in the future it will be helpful to identify the factors that are related to VA malfunction. METHODS: In a retrospective analysis we analysed the types, duration and primary rate of patency of 1033 permanent vascular accesses in 544 consecutive patients established during a 13-year period in a tertiary care hospital. Patient characteristics, incidence, and risk factors related to VA failure were registered. In addition, VA outcomes in patients who started haemodialysis with a catheter and in whom initial VA failure occurred were analysed separately. RESULTS: Forty-five per cent of patients required a central catheter at the start of HD, but 92% of them were being dialysed with an a-v fistula at the last observation. The total number of complications was 0.24 episodes per patient per year at risk and the rate of thrombosis 0.1. A total of 52% of patients were dialysed throughout the observation period with their initial a-v fistula; 9.3% had more than three episodes of VA failure. The radiocephalic a-v fistula was the VA with the best median duration, exceeding 7 years, but also the type that had the highest initial failure rate, i.e. 25% of patients and 13% of the events. The brachiocephalic a-v fistula was the second most frequent type of VA, with a median duration of function of 3.6 years, in contrast to the humerobasilic a-v fistula, which exceeded 5 years. Average patency of the different types of grafts did not exceed 1 year, with the exception of the autologous saphenous graft with a median duration of function of 1.4 years. Patients with glomerulonephritis had the best function rates for their VA, the median exceeding the duration of the study, whereas in half of the diabetic patients it was less than 1 year. The duration of patency of the VA was twice in patients below age 65 years and in elderly males compared to elderly females. Patients who started HD with a catheter, as well as those with initial VA failure, had a higher rate of VA failure in the subsequent course on RRT. CONCLUSION: The radiocephalic and the humerobasilic a-v fistulae are the two types of VA with the longest duration of function, although a high rate of initial failure is seen with the radiocephalic a-v fistula. Age, female gender, presence of diabetic nephropathy, start of dialysis with a catheter, and failure to wait for initial maturation of the VA are risk factors, and account for the majority of VA failures during RRT.

Aged↗
PubMed1999

Outcome of hepatitis C virus-associated membranoproliferative glomerulonephritis after liver transplantation.

BACKGROUND: Hepatitis C virus was the most frequent cause of liver failure requiring liver transplantation in our series. Hepatitis C virus infection has been associated with glomerulonephritis and, more frequently, type I membranoproliferative glomerulonephritis. Renal disease in patients with liver failure is often clinically silent and difficult to diagnose; thus, biopsy is required to establish the diagnosis. Our aim was to study the evolution of six patients diagnosed with membranoproliferative glomerulonephritis some months before liver transplantation. METHODS: Liver transplantation alone was performed in four patients and combined liver-kidney transplantation in the remaining two, who were on hemodialysis for kidney failure. These patients were followed for a mean of 38.3+/-7.8 months. Evolution of proteinuria, renal function, hepatic function, and hepatitis C virus activity was studied. RESULTS: In the four patients who underwent liver transplantation alone, proteinuria became negative initially and renal function remained stable. Proteinuria reappeared and renal function was altered in two of these patients at 17 and 36 months of follow-up, respectively, coinciding with a recurrence of active chronic hepatitis. In the two patients who received a combined liver-kidney transplant, proteinuria became negative, and their renal grafts currently maintain normal renal function. CONCLUSIONS: Membranoproliferative glomerulonephritis does not constitute an absolute contraindication for liver transplantation alone; combined liver-kidney transplantations are reserved for patients with end-stage kidney failure. Proteinuria is reversed after liver transplantation, and recurrence seems to be associated with severe hepatitis C virus hepatic allograft disease relapse.

Adult↗
PubMed1995

Hepatitis C virus infection in renal transplant recipients: epidemiology, clinical impact, serological confirmation and viral replication.

The presence and significance of hepatitis C virus infection was evaluated in 241 renal transplant recipients from our hospital. Hepatitis C virus antibodies were tested by second-generation enzyme immunoassay, followed by second- and third-generation immunoblot assays (RIBA-2 and RIBA-3); hepatitis C virus RNA was measured by nested polymerase chain reaction. Hepatitis C virus antibodies, which were detected in 46.5% of patients, were mainly present before transplantation and independently associated with the total amount of transfused blood, time in hemodialysis and duration of posttransplant follow up. Liver dysfunction (alanine aminotransferase elevation) was observed in 50% of antibody-positive recipients, and 92.5% of patients with chronic liver disease without hepatitis B infection were infected with hepatitis C virus. Most antibody-positive patients (78.4%) tested positive by RIBA-2, but 21.6% were indeterminate; RIBA-3 was positive in 90% of these indeterminates. Hepatitis C virus RNA detection was positive in 96% of antibody-positive cases tested, in 20% of patients who were already anti-HCV negative before transplantation and also demonstrated persistence of HCV infection in all cases who, being antibody positive prior to transplantation, lost these antibodies during follow up (9% of transplanted patients). In conclusion, hepatitis C virus infection is extremely prevalent in renal transplant recipients from Spain and is the main cause of chronic liver disease in these patients. Confirmation by supplemental assays of anti-HCV antibodies is not necessary, but hepatitis C virus RNA testing is indispensable to detect those cases who lose or do not develop hepatitis C virus antibodies.

Adult↗
PubMed1994

[Isotopic renogram after captopril administration: clinical experience in the assessment of the hypertensive patient].

BACKGROUND: Isotopic renogram allows renal function to be estimated in both kidneys independently. The glomerular filtrate in ischemic kidneys is largely dependent on the tone of the efferent glomerular arteriolae and therefore on the concentration of circulating angiotensin II. METHODS: In 42 patients with severe high blood pressure in whom renal angiographic study was carried out for suspicion of vasculo-renal hypertension, an isotopic renogram using 99m Tc-DTPA as a tracer was performed in basal conditions and following the administration of 50 mg of oral captopril. RESULTS: In 21 patients both the angiographic examination and the post-captopril renogram were normal. In 16 patients in whom uni or bilateral stenosis higher than 50% of the lumen of renal artery was observed on angiographic examination, the post-captopril renogram showed changes. In 5 patients the angiography was normal while the renogram showed evaluable changes. No false negatives were observed in the post-captopril renogram, however the basal renogram was not demonstrative in 6 patients with stenosis of the renal artery. Sensitivity of the test was thus 100% and specificity 80%. The positive predictive value was 76% and the negative predictive value 100%. CONCLUSIONS: The post-captopril renogram may be a useful test in the functional study of renal behaviour in patients with vasculo-renal hypertension.

Adolescent↗
PubMed1993

Successful treatment of haemodialysis catheter-related sepsis without catheter removal.

Thirty-six Permcath double-lumen catheters implanted in 36 chronic renal failure patients for haemodialysis treatment were prospectively studied. When catheter-related sepsis was suspected a quantitative blood culture was obtained simultaneously from the catheter and from a peripheral vein. If bacterial colonies in the catheter blood specimen were fourfold greater than identical bacterial colonies in the peripheral blood specimen, the test was considered indicative of catheter sepsis and an empirical antibiotic regimen was begun while the central line remained in situ. Eleven patients suffered 13 episodes of catheter-related sepsis. Staphylococcus epidermidis and Pseudomonas aeruginosa accounted for 77% of the strains isolated. All episodes were successfully treated with vancomycin or ciprofloxacin and yielded negative results on follow-up quantitative blood cultures. Fever subsided within the first 48 h of therapy and no complications occurred. None of these patients required catheter removal for cure of the catheter-related sepsis.

Adult↗
PubMed1992

[Cutaneous trophic disorders secondary to arteriovenous fistula for hemodialysis].

The arteriovenous fistula is the vascular access of choice for hemodialysis treatment in patients with chronic renal failure. Clinical occurrence of local circulatory troubles caused by the fistula in addition to arterial robbery or venous hypertension are infrequent but may provoke serious consequences. Two patients with arteriovenous fistula with cutaneous trophic disorders secondary to the venous hypertension syndrome (case 1) and to the arterial robbery syndrome (case 2) are present. Prevalence, pathogenic factors, physiopathology, clinical aspects, and diagnosis and treatment of both syndromes are reviewed. Finally, the difficulty and morbidity of the creation of an efficient arteriovenous fistula in the diabetic patient is underlined.

Adult↗