[Two centers with a native fistula prevalence higher than 90%: organization and activity]. / Due centri accomunati da una prevalenza di fistole con vasi nativi maggiore del 90%: attività e modelli organizzativi a confronto.

Vascular access (AV) dysfunction is a major cause of morbidity and hospitalisation in hemodialysis population. Despite of guidelines statements which consider native arteriovenous fistula (nAVF) the gold standard, epidemiological studies still show a decline in their prevalence with an increase of central venous catheters (CVC). In this study we compared the activity of two Dialysis Units both characterized by a high prevalence (> 90%) of nAVF, in order to highlight the possible reasons. No collaboration existed between the two centres until the decision to design this work. The "policy" on creation and management of vascular access and organizational models of the two centres were assessed, in particular focusing on surgeons, presence of dedicated nephrologists, preoperatory ultrasound evaluation, follow-up and diagnosis of complications, resort to interventional radiology, complications management, in particular the timing of intervention after AVF thrombosis. Of the two dialysis populations were analysed: age, time on dialysis, coexistence of diabetes and the prevalence of various types of vascular access to 31 December 2007. It was evaluated the AV incidence in the last 4 years. The statistical analysis was performed by T student and Chi square tests. There were no substantial differences in the organizational models of the two centres, which had both a routine ECD use in preoperatory mapping and in monitoring of complications; in case of thrombosis both centres performed surgery within 12-24 hours; in case of stenosis both centres performed the correction, surgical or by angioplasty, within 15 days from the diagnosis. Another common element was the presence of a multidisciplinary team with a interventionist nephrologist, a vascular surgeon and a vascular interventional radiologist, where nephrologist has the coordination role. The data analysis showed a prevalence of nAVF in the two centres of 92.5% and 96.1%, Pescara and Lecce respectively, with a prevalence of forearm nAVF of more than 80% and 90% respectively. The analysis of incident interventions showed high percentage of forearm AVF in case of revisions for complications (stenosis, thrombosis), and a little recourse to proximal AVF and graft.

[Clearances in automated intermittent peritoneal techniques: a new formula to use morning blood sampling]. / Clearances in tecniche peritoneali automatizzate intermittenti: una nuova formula per utilizzare il prelievo ematico del mattino.

According to the main guidelines, dialysis adequacy monitoring is fundamental in the management of patients on peritoneal dialysis. In order to avoid mistakes in the calculation of the peritoneal urea and creatinine clearance in patients on dialysis with intermittent techniques, the collection of blood samples about 6 hours after the end of the dialysis session is advised. In fact, because the creatinine and urea values at the end of dialysis (the morning values in NIPD) are the lowest, the resulting clearances could be overestimated. The mean values between the start and the end of the dialysis session are considered the gold standard. However, collecting a blood sample at 2.00 p.m. may be difficult and uncomfortable both for the nurse and the patient. In this paper we present two formulas (the first for urea and the second for creatinine) which, starting from the values at the end of dialysis, predict the values at the beginning of the session and consequently the mean values. The aim of this study was to validate the formulas by evaluating their capability to predict the mean urea and creatinine values when only end-of-dialysis blood sampling was performed. Statistical analysis was carried out using the Bland-Altman test. The two formulas proved able to predict the mean urea and creatinine values; the differences between the measured and calculated values were not statistically significant.