Search PubMed⌕ Search

Biomedical subjects

P M Ghezzi

Publications and source records attributed to P M Ghezzi.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Vascular access in hemodialysis. Surveillance and role of percutaneous transluminal angioplasty].

The function of vascular shunts in hemodialysis plays a vital role for the efficiency and effectiveness of replacement therapy. A study was performed in 147 patients undergoing periodical hemodialysis with distal FAV (no = 86), proximal FAV (no = 33), PTFE grafts (no = 23), Canaud-Tesio catheters (no = 7). A protocol for function evaluation was developed which also included the calculation of overall recirculation (R), that was found to be 10.8 + 7% (using the three blood sample method). In 28/143 patients the monitoring protocol recommended the use of angiography which identified abnormalities in 78% of cases, before the onset of thrombotic phenomena. In particular, surgical radiology was able to resolve 94% of cases in which angiography revealed a stenosis using percutaneous transluminal angioplasty and/or the insertion of one or more stents.

Angiography↗
PubMed1995

Are serum albumin and cholesterol reliable outcome markers in elderly dialysis patients?

Albumin and cholesterol are considered reliable outcome markers in dialysis patients; their influence, however, may also be related to non-independent factors, such as age and presence of co-morbid conditions. The aim of the study was an analysis of four outcome markers, assessed at start of dialysis: age, high risk conditions, cholesterol and albumin levels. Data were obtained from the Piedmont Dialysis and Transplantation Registry (northern Italy, about 4,400,000 inhabitants, 21 dialysis centres, open acceptance since mid-1970s, 5661 patients on file at 31 December 1992). Prevalence of albumin and cholesterol in the normal range increases with age; in each age group prevalence in the range is higher in patients at high risk. However, influence of these biochemical parameters is evident also in no-risk cohorts, thus identifying a subgroup with poorer prognosis also in the population without any identified classic risk factor. The influence of albumin, more evident in the population studied compared with cholesterol, is reflected by impaired survival of low-albumin patients (age > or = 65 high risk at 1 year: 60.7% vs 76.6%, P = 0.0052; age > or = 65 non-high risk, at 1 year: 76.5% vs 90.7%, P = 0.0001). In conclusion, albumin and cholesterol, assessed at start of dialysis, are reliable outcome markers even in elderly patients, identifying, in this high mortality cohort, a subgroup with poorer prognosis. If and how their effect may be reversed by dialysis therapy remains to be assessed.

Adolescent↗
PubMed1995

Acid-base balance determination on ultrafiltrate in two-chamber technique hemodiafiltration (PFD).

Correction of the acid-base balance in uremic patients during hemodiafiltration (HFD) may be biased by an inadequate monitoring of pH and blood gases. HDF performed with the two-chamber technique (PFD) generates pure ultrafiltrate (uf) unmixed with dialysate. We carried out 84 determinations of HCO3- levels in 15 different PFD patients by measuring the pH and pCO2 of the uf, then correlated the values with those simultaneously evaluated on arterial blood with standard methods. The mean HCO3- levels (mmol/L) were 23.21 +/- 2.49 in blood samples and 25.54 +/- 3.07 in uf, with a mean difference of -2.33 +/- 1.46. Statistical analysis gave: t = 13.5 (p = O) (one-sample analysis), r = 0.86 (p = 0) (linear regression analysis) and a good agreement between the two clinical measurements (81 out of 84 data points fell within the 95% confidence interval) (Bland-Altman analysis). In conclusion, we suggest that during HDF performed with the two-chamber technique, the patient's HCO3- level can be monitored on the uf without blood sampling.

Acetates↗
PubMed1994

[Is a monthly biochemical check-up useful more than 2 years after kidney transplantation?].

Over the course of the years many transplantation centres have altered their pattern of periodical check-ups in patients with stable renal function, in some cases considerably prolonging the intervals. Peripheral centres, which are attended by patients after kidney transplantation, must reconcile the follow-up requirements made by various reference centres. The authors carried out a retrospective evaluation of 39 patients who, at 30-6-1992, had had kidney transplants for more than two years, taking into consideration a series of hematochemical tests indicative of the main functional alterations (creatininemia, hepatic enzymes, hemochrome, cyclosporin assay). In the 31 patients receiving monthly check-ups after the second year, changes in cyclosporinemia were on average significantly more frequent in comparison to variations in other parameters. This finding, together with the need for a careful control of transplant patients, would appear to confirm the value of monthly check-ups. However, the positive experience of some centres which begin to space out periodical check-ups at an early stage and report good organ survival, opposes the previous affirmation. Lastly, it emerges from this study that patients undergoing frequent controls even after the second year of transplantation have significantly lower organ survival.

Biomarkers↗
PubMed1992

Prevalence of HCV antibodies in a uraemic population undergoing maintenance dialysis therapy and in the staff members of the dialysis unit.

We studied, by both 1st and 2nd generation assay, the prevalence rate of HCVAb in a population of 141 dialysis patients, 37 transplanted patients and 55 staff members. From this study emerges a higher sensitivity of the 2nd generation HCVAb test (15.38 versus 36.79% of positive responses, respectively), and a significant positive correlation between lengths of dialysis period. We have not found a significant difference between HCVAb-positive and -negative patients in relation to the blood transfusions. None of the 21 CAPD patients (home dialysis) resulted positive, even if transfused. Two nurses were positive. In our experience, the environmental factor seems more important. Since the isolation of the positive patients is an effective but not feasible measure, it is necessary to improve the operating management of the hemodialysis sessions, avoiding any contact between patients via material (instrumentation, monitors) and teaching the staff members to use severe preventive standards with all hemodialysis patients.

Cross Infection↗
PubMed1991

Use of the ultrafiltrate obtained in two-chamber (PFD) hemodiafiltration as replacement fluid. Experimental ex vivo and in vitro study.

PFD (Paired Filtration Dialysis) is the only hemodiafiltration (HDF) technique in which the ultrafiltrate (UF) is continuously available not mixed with the dialysate. As with all convective or prevailingly convective techniques, a replacement fluid is necessary in an amount equal to the difference between the UF and the desired weight loss. This replacement fluid (R) must have an adequate electrolytic balance (Na+, Ca++, and buffer), and must be sterile and pyrogen-free. Using an uncoated adsorbent charcoal cartridge, we "regenerated" the UF obtained in PFD, eliminating the small (except for urea, which was later eliminated by diffusion in the dialyzing section of the PFD system) and the medium-to-large molecules (vit B12 and myoglobin in vitro and beta-2-microglobulin (B2m) and (hANP) in vivo), but not the electrolytes and the endogenous bicarbonate, so as to verify its possible use as R. This technique, experimentally performed in 12 patients under HDF treatment with standard PFD, with a total mean UF of 9650 +/- 875 ml and the use of 130 g of uncoated charcoal, produced a solution with the following composition: Na+ 135.4 +/- 2.4 mmol/l, K+ 3.4 +/- 1.23 mmol/l, Ca++ 1.18 +/- 0.14 mmol/l, HCO3- 26.7 +/- 2.3 mmol/l, phosphates 2.88 +/- 0.81 mg/dl, urea 63 +/- 14 mg/dl, creatinine 0.08 +/- 0.02 mg/dl, uric acid 0.05 +/- 0.0 mg/dl, beta-2 microglobulin 0.5 +/- 0.5 mg/l, and hANP 4.15 +/- 5 pg/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellulose↗
PubMed1983

Echotomography in arteriovenous fistulae.

We employed Echotomography (by 2.25-5MHz probes) as a quick procedure to measure the vessel diameter at definite points to detect aneurysms and their evolution, to evaluate the arteriovenous fistula (AVF) characteristics, to detect haematoma, thrombi, and collateral vessels. Echotomography is a non-invasive technique which may be performed repetitively even immediately after AVF surgery. It was most valuable in the examination of proximal AVF and internal shunts (autologous venous and bovine carotid grafts). Echotomography has proved to be accurate in studying the initial morphological and functional evaluation and follow-up of AVF.

Arteriovenous Shunt, Surgical↗
PubMed1980

[Kinetics of anticoagulation in hemodialysis. Sequential study of single, intermittent and continuous heparinization].

A sequential real-time study was run to monitor plasma heparin values following three standard dose protocols during 4-hr dialysis, using an enzymatic method. One group of patients was given a single dose of 7000 IU at the commencement of dialysis, a second group 5000 IU at the start and 2500 IU at the end of the third hour, and a third group 2500 IU at the start and 1500 UI/hr for four hours. Plasma levels were checked every hour and ranged from 0.702 IU/ml (+/- 0.069) (start) to 0.290 IU/ml (+/- 0.079) (end) in the first group, 0.552 (+/- 0.116) to 0.312 (+/- 0.09) in the second, and 0.456 (+/- 0.113) to 0.314 (+/- 0.063) in the third. Correlation of heparin levels with coagulation time led to the establishment of an optimal range of 0.2 to 0.6 IU/ml.

Blood Coagulation Tests↗
PubMed1980

["Clinical clearance" and "weekly clearance" of urea in periodical hemodialytic treatment].

Starting from the hypothesis that small molecules are freely diffusible, a simple formula is proposed for the determination of real ureic clearance during dialysis. This automatically allows for all variables (blood flow and flow of the dialysing solution, temperature, physical and/or chemical state of the membrane, level of solute concentration, transmembrane pressure, etc.). On the basis of this formula, a calculation system is also proposed for assessing weekly ureic clearance levels and hence the real efficiency of treatment. This system may also be applied to peritoneal dialysis and permits optimisation of substitutive treatment. It is thus easier to select the best filter and rhythms for each patient.

Humans↗
PubMedDate not supplied

Hemodiafiltration without replacement fluid. An experimental study.

Paired filtration dialysis (PFD) is the only hemodiafiltration (HDF) technique in which the ultrafiltrate is continuously available but not mixed with the dialysate. As is the case during all convective or predominantly convective techniques, use of a replacement fluid is necessary in an amount equal to the difference between the ultrafiltrate and the desired patient weight loss. This replacement fluid must have an adequate electrolytic composition (Na+, Ca++, and buffer), and must be sterile and pyrogen free. Using an uncoated adsorbent charcoal cartridge (130 g), the ultrafiltrate obtained in PFD was regenerated, eliminating both the small (except for urea, glucose, and phosphates) and medium-to-large solutes but not the electrolytes and bicarbonate. This verified the ultrafiltrate's possible use as replacement fluid. This technique experimentally studied during 24 standard PFD sessions, with a total mean ultrafiltrate of 9,950 +/- 860 ml, allowed a replacement solution to be obtained with the following mean +/- SD composition: pH 7.467 +/- 0.122, HCO3- 27.0 +/- 2.12 mmol/L, Na+ 137.4 +/- 2.6 mmol/L, K+ 4.1 +/- 0.83 mmol/L, Ca++ 1.12 +/- 0.19 mmol/L, urea 68.3 +/- 16.2 mg/dl, creatinine 0.08 +/- 0.02 mg/dl, uric acid 0.05 mg/dl, phosphates 2.77 +/- 0.71 mg/dl, beta-2 microglobulin 0.5 +/- 0.4 mg/L, and atrial natriuretic peptide 4.41 +/- 5.6 pg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Charcoal↗