Imaging work-up for peritoneal access care and peritoneal dialysis complications.

Peritoneal dialysis (PD) represents a treatment opportunity for patients with end-stage renal failure, but it has particular complications that sometimes force cessation of this procedure (1- 9). These complications are due to the presence of the peritoneal catheter and of dialysis solution within the peritoneal cavity. Infections are the most common complications of PD, followed by mechanical complications. Diagnostic imaging of the complications of PD is important because such an evaluation can aid in the diagnosis and in the decision making process about the treatment. In this review we present the main radiologic investigations employed: plain radiograph, US, peritoneography, computed tomography peritoneography, magnetic resonance peritoneography, peritoneal scintigraphy. To diagnose catheter-related problems plain radiograph, ultrasonography and peritoneography can be useful. US is useful in diagnosing and following-up exit-site and tunnel infections. Peritoneography and CT-peritoneography, alone or in combination, can be recommended as gold standard investigation to assess mechanical peritoneal dialysis complications, such as catheter malfunction, leaks, hernias and sclerosing peritonitis. Newer methods, such as MR peritoneography or scintigraphy could be useful in selected patients, on center-based experience. An appropriate use of radiology may significantly improve technique survival, morbidity and mortality of patients treated with PD.

Scant reliability of Co/Ct ratio in urea kinetic formulas.

The ratio initial/final urea value is used in urea kinetic formulas. To assess its reliability we employed mass balances and urea clearances to study 15 hemodialysis treatments divided in several parts. The mass balances clearly indicated urea disequilibrium. In the first phases of dialysis, urea extraction, measured by dialysate collection, was lower than the corresponding change in urea pool, whereas in the later phases the opposite occurred. On account of this lack of equilibrium, clearances bases on the Co/Ct ratio (K2) are less reliable than standard clearances derived from total dialysate collection (K1): in the first quarter of dialysis, K2 is greater than K1 (p less than 0.01), while in the 3rd and 4th quarters it is lower. The comparison of clearances in a cumulative way showed a significant fall in K2 (p less than 0.01) while K1 remained stable. From a practical point of view, aberrations induced by non monocompartmental urea behaviour are negligible, and do not invalidate the usefulness of the single-pool Gotch model in clinical practice. However, at least in experimental work, the limits of urea kinetic formulas must be taken into account.

[High-efficiency hemodialysis. Review of the literature and initial clinical experience]. / L'emodialisi ad alta efficienza. Revisione della letteratura e prime esperienze cliniche.

A literature review allows us to distinguish two types of high efficiency therapy: HED (high efficiency dialysis), with low ultrafiltration coefficient membranes, and HFD (high flux dialysis), with high ultrafiltration coefficient membranes. Data reported show an unchanged hematochemical with the same, or better, treatment tolerance, but there are few data on hydrosaline balance (and correlate hypertension) and middle moleculas removal. Finally we report the experience of our centre in 59 months of treatment in four patients.

[Wegener's granulomatosis. Diagnosis and follow-up of 7 cases]. / Granulomatosi di Wegener. Diagnosi e follow-up di 7 casi.

Wegener's granulomatosis (WG) is a rare small vessels necrotizing and granulomatous systemic vasculitis which usually affects the respiratory-tract and the kidneys. Diagnosis is often difficult, but has become easier with antineutrophil cytoplasmic antibodies (ANCA) detection that may justify a more aggressive biopsy policy also in the elderly. Classic treatment with steroids and oral cyclophosphamide (CY) has proven to be of benefit, but side-effects are severe and frequent and the search for less toxic therapeutic schemes should be encouraged. We treated with intravenous pulses of CY (1 g/m2 monthly for 6 months, every two months for the following 6 and quarterly for another year) 5 of 7 patients with WG recently admitted to our institution. We obtained a quick, complete response in 4 of these patients, with no side effects, nor relapses, after a mean follow-up of 17 months. The only patient who did not respond was identified soon after the beginning of the treatment because of a poor reduction of ESR and could be shifted to oral administration of CY successfully. From our still limited experience CY intravenous pulses have proven to be safe and effective enough to advice its use as the first-choice treatment for WG.

[Surgical interventions in dialysis patients in Piedmont: data from the Regional Registry. Working Group of the Piedmont Registry of Dialysis and Transplantation]. / Interventi chirurgici nei pazienti in dialisi in Piemonte: dati dal Registro Regionale (RPDT). Gruppo di lavoro dell'RPDT.

In this work surgical events in a large population of chronic dialysis patients are analysed. Data are obtained from the Regional (Piedmont) Registry of Dialysis and Transplantation (RPDT), that has collected information since 1981 about all chronic dialysis patients in the Region. Since 1984, causes of admission to-hospital are registered. Surgical causes of hospitalization, for purposes not related to uremia, were 538 (20% of all surgical admissions). In patients younger than 65 years, these hospitalizations account for about 6% of the cases, whereas in patients older than 65 they are less than 5%. As expected, a higher number of surgical operations is observed in diabetics, while on the contrary the lowest is performed in nephroangiosclerosis patients. Cardiovascular and bowel diseases represent almost 50% of all surgical needs. Postoperative mortality was 5.8% within 45 days from admission. Cardiac and infectious diseases and cachexia represent the more frequent causes of death. In 27 out of 28 cases at least one high risk condition was present.

[Bartter's syndrome in children and adults. Study of 6 cases]. / La sindrome di Bartter nel bambino e nell'adulto. Studio di 6 casi.

Six patients (3 children and 3 adults) with the clinical and biochemical features of Bartter's syndrome are presented. Pediatric cases included a more severe form, in one patient, with physical and mental retardation, hypercalciuria and nephrocalcinosis, and a less severe one, including two patients, with milder clinical features, low calcium and high magnesium excretion and hypomagnesiemia. Adult patients were affected by either the mild congenital form (case n. 4) or the acquired variety (cases n.5 and 6). Tubular function was investigated in the 3 adults by assessing clearance measurements during maximal diuresis. There was a defective fractional distal solute reabsorption (FDR) ranging between 0.52 and 0.60. This was well below the results obtained in one patient with psychogenous vomiting (FDR 0.94) and comparable to those in two patients with interstitial nephropathies caused by vesico-ureteral reflux (FDR 0.63 and 0.67 respectively). We concluded that: 1) the etiopathogenetic spectrum of Bartter's syndrome corresponds to different clinical presentation (mild, heavy, congenital or acquired varieties), and alterations in mineral and electrolyte renal handling; 2) reduction in FDR is a feature neither essential nor exclusive of this syndrome.

[Cachexia during dialysis]. / Cachessia in corso di dialisi.

In the Italian language, the term cachexia is a rather picturesque synonym of "marasma senile", "senile marasmus", an old definition involving not only old-age, but specifically senility, the end of the ageing process and marasmus, a stagnant and hopeless situation in which all superior organised functions have disappeared. The problem of cachexia during dialysis is complex and several discordant opinions exist at this regard, partly accounted by different definitions of this sluggish entity (or non entity). Actually, the basic question is very simple: is cachexia the cause or the effect of failure of dialysis treatment? The aim of this study was an evaluation of epidemiological data from the Dialysis and Transplantation Registry of Piedmont, a northern Italian Region with about 4,350,000 inhabitants, 22 public dialysis Centers, open acceptance to dialysis since the mid seventies, a multiple choice dialysis system developed in the eighties. In the period 1981-1995, 764 patients died in conditions of cachexia. This figure is 20.9% of all deaths recorded, 27.4% over age 65 and 34.7% over age 75. Despite a likewise significant increase in age and presence of comorbid factors, an improvement of patients survival, that reach statistical significance in the old age group (> or = 65 yrs), was observed.

Determinants of oxalate balance in patients on chronic peritoneal dialysis.

We assessed plasma levels and removal rates of oxalate in 24 patients on chronic peritoneal dialysis (CPD) for oxalosis-unrelated renal failure. The ion-chromatographic (IC) measurements of oxalate in plasma, dialysate, and urine (in seven patients with residual renal function) were used to calculate peritoneal and renal clearances of oxalate. The serum state of saturation with calcium oxalate was calculated by means of a computer-based model system. Patient data were compared with those from 19 healthy individuals. Peritoneal clearance of oxalate was 6.3 +/- 4.7 mL/min, ie, 8% of the normal renal clearance. As a result, both plasma oxalate and calcium oxalate saturation were higher than in controls and did not overlap. Plasma was supersaturated with calcium oxalate in only two of 24 patients (8%). Removal of oxalate by dialysis was related to the amount of fluid infused. Overall removal of oxalate (dialysate plus urine) was similar to 24-hour excretion of normal subjects and was taken as a measure of its generation. Oxalate generation rate was dependent on protein (whole and animal) intake, but not on caloric intake or pyridoxine status. Pyridoxine supplementation, 75 and 300 mg daily for 1 months, was not effective in reducing plasma levels or generation rates of oxalate. Residual renal function had a minor influence on oxalate patterns. We conclude that current programs are adequate to maintain oxalate balance in patients on CPD under basic conditions.

Acute renal failure in obstetric complications.

Early postpartum disseminated intravascular coagulation (DIC) was demonstrated by serial coagulation studies in 10 cases of acute renal failure (ARF) following obstetric complications (6 abruptio placentae, 3 retained placental fragments, 1 prolonged intrauterine fetal death). DIC abated within 48 hours irrespective of the therapeutic schedules employed. Renal damage was evidenced by a varying number of days of oligoanuric (6 cases) or polyuric (4 cases) ARF which always required dialytic treatment. Full renal recovery occurred in 9 cases. One patient died and no histological studies were performed. Renal damage seemed to correlate less with DIC than with the degree of anemia and shock.