[Thrombosis in Hemodialysis Tunnelled Central Venous Catheters: From Pathogenesis to Therapeutic Strategies].

Central venous catheter-related thrombosis is a frequent non-infectious complication, typically associated with catheter dysfunction and hemodialysis inadequacy. Central venous catheters (CVCs) are categorized into non-tunnelled and tunnelled types, wherein the choice depends on patient's clinical conditions and the diagnostic and therapeutic workup. Tunnelled CVCs (tCVCs) are sought whenever an arteriovenous fistula is unfeasible or as primary access in patients with poor prognosis.

Rethinking an effective AV fistula-graft screening program. An "A B C".

The goal of a vascular access screening program is to detect and preemptively correct hemodynamically significant stenosis, however, a practice pattern allowing to implement such a program still remains to be defined. Achieving balance between the increase in access-related procedures by adopting an aggressive screening program, and the risks associated with the absence of any screening program, i.e.

How to manage catheter-related right atrial thrombosis: Our conservative approach.

Background: Catheter-related right atrial thrombosis is an underestimated, severe, and life-threatening complication of any type of central venous catheters. No clear-cut epidemiological data are available. Catheter-related right atrial thrombosis is often asymptomatic; however, it can lead to serious complications and death.

[Membranoproliferative glomerulonephritis with relapsing episodes of acute kidney injury in the Schnitzler syndrome].

The Schnitzler syndrome (SS) is a rare and underdiagnosed entity that associates a chronic urticarial rash, monoclonal IgM (or sometimes IgG) gammopathy and signs and symptoms of systemic inflammation. During the past 45 years the SS has evolved from an elusive, little-known disorder to the paradigm of a late-onset auto-inflammatory acquired syndrome. Though there is no definite proof of its precise pathogenesis, it should be considered as an acquired disease involving abnormal stimulation of the innate immune system, which can be reversed by the interleukin 1 (IL-1) receptor antagonist anakinra.

Is the removal of a central venous catheter always necessary in the context of catheter-related right atrial thrombosis?

Catheter-related right atrial thrombosis is a severe and life-threatening complication of central venous catheters in both adult and young patients. Catheter-related right atrial thrombosis can occur with any type of central venous catheters, utilized either for hemodialysis or infusion. Up to 30% of patients with central venous catheter are estimated to be affected by catheter-related right atrial thrombosis; however, neither precise epidemiological data nor guidelines regarding medical or surgical treatment are available.

Kidney involvement in the Schnitzler syndrome, a rare disease.

The Schnitzler syndrome (SS) is a rare and underdiagnosed entity that associates a chronic urticarial rash, monoclonal IgM (or sometimes IgG) gammopathy and signs and symptoms of systemic inflammation. During the past 45 years, the SS has evolved from an elusive little-known disorder to the paradigm of a late-onset acquired auto-inflammatory syndrome. Though there is no definite proof of its precise pathogenesis, it should be considered as an acquired disease involving abnormal stimulation of the innate immune system, which can be reversed by the interleukin-1 receptor antagonist anakinra.

The impact of haemodialysis arteriovenous fistula on haemodynamic parameters of the cardiovascular system.

Background: Satisfactory vascular access flow (Qa) of an arteriovenous fistula (AVF) is necessary for haemodialysis (HD) adequacy. The aim of the present study was to further our understanding of haemodynamic modifications of the cardiovascular system of HD patients associated with an AVF. The main objective was to calculate using real data in what way an AVF influences the load of the left ventricle (LLV).

Efficacy and Safety of a New Technique of Conversion from Temporary to Tunneled Central Venous Catheters.

The usually applied conversion technique from temporary to tunneled central venous catheters (CVCs) using the same venous insertion site requires a peel-away sheath. We propose a conversion technique without peel-away sheath: a guide wire is advanced through the existing temporary CVC; then, a subcutaneous tunnel is created from the exit to the venotomy site. After removing the temporary CVC, the tunneled one is advanced along the guide wire.

Ranking of factors determining potassium mass balance in bicarbonate haemodialysis.

Background: One of the most important pathogenetic factors involved in the onset of intradialysis arrhytmias is the alteration in electrolyte concentration, particularly potassium (K(+)).

Methods: Two studies were performed: Study A was designed to investigate above all the isolated effect of the factor time t on intradialysis K(+) mass balance (K(+)MB): 11 stable prevalent Caucasian anuric patients underwent one standard (∼4 h) and one long-hour (∼8 h) bicarbonate haemodialysis (HD) session. The latter were pair-matched as far as the dialysate and blood volume processed (90 L) and volume of ultrafiltration are concerned.

Probing the dry weight by bioimpedance: the resistance stabilization test.

Probing dry weight (DW) was largely dependent on clinical subjective estimate until recently. New bedside non-invasive tools have been developed with the aim of providing more objective information on volume status and guiding physicians in the quest for DW. Among them, bioimpedance appears to be very promising in the achievement of this goal.

[A technique for inserting inadvertently removed tunneled hemodialysis catheters through the original exit site].

Accidental loss of tunneled hemodialysis (HD) central venous catheters (CVCs) is a rare complication. In the absence of other sites available for positioning a new CVC, the lack of a vascular access exposes the patient to a high risk of mortality. The technique for inserting inadvertently removed tunneled CVCs using the original exit site has never gained popularity and has been used, although with good results, in selected cases only.

[Rescue endovascular revascularization in two patients with bilateral atherosclerotic renal artery occlusion].

Renal artery stenosis is found in 2% and 40% of general and high cardiovascular risk populations, respectively. Atherosclerotic renal artery stenosis (ARAS) has become an increasingly recognized clinical condition, especially in older or otherwise atherosclerosis-prone populations. This increase in prevalence has led to a dramatically increased use of percutaneous transluminal renal angioplasty.

Sodium setpoint and gradient in bicarbonate hemodialysis.

Background: The demonstration of an individual osmolar setpoint in hemodialysis (HD) is crucial to individualize dialysate sodium concentrations. Furthermore, the diffusive gradient between plasma and dialysate sodium is important in the "fine tuning" of the intradialytic sodium mass balance (MB).

Methods: The design of this study included part A: a retrospective analysis of predialysis plasma sodium concentrations extracted from a 6-year database in our HD population (147 prevalent white anuric patients); and part B: study of intradialytic sodium kinetics in 48 patients undergoing one 4-hour bicarbonate HD session.

Optimizing the dialysate calcium concentration in bicarbonate haemodialysis.

Background: There is no consensus regarding the optimal dialysate calcium concentration (DCa) during haemodialysis (HD). Low DCa may predispose to acute arrhythmias, whereas high DCa increases the long-term risk of soft tissue calcifications.

Methods: Twenty-two HD patients treated in four dialysis centres underwent two HD sessions, respectively, with 1.

The systemic capillary leak syndrome: a scarcely known nephrological entity.

The idiopathic systemic capillary leak syndrome (SCLS) is a rare life-threatening disorder characterized by periodic episodes of hypovolemic shock, due to plasma leakage from the intravascular to the interstitial space, as reflected by accompanying hypoalbuminemia, hemoconcentration and edema. Here we report the case of a 65-year-old woman affected by SCLS who required aggressive resuscitation with norepinephrine, steroids, albumin and crystalloids. Then, a long-term prophylaxis with a ß(2)-adrenergic receptor agonist and theophylline was started.

Effect of dialysate calcium concentrations on parathyroid hormone and calcium balance during a single dialysis session using bicarbonate hemodialysis: a crossover clinical trial.

Background: In bicarbonate-based hemodialysis, dialysate total calcium (tCa) concentration may have effects on mineral metabolism.

Study Design: Randomized crossover trial of 3 dialysate tCa concentrations (2.5, 2.

Effects of different dialysate calcium concentrations on intradialysis hemodynamic stability.

Background: The interplay of correct solute mass balances, such as those of sodium (Na+), potassium (K+) and total calcium (tCa) (Na+MB, K+MB and tCaMB, respectively) with adequate ultrafiltration volumes (VUF) is crucial to achieving hemodynamic stability during hemodialysis (HD).

Methods: Twenty-two stable anuric uremic patients underwent three 4-hour bicarbonate HD sessions, each with a different dialysate tCa concentration (1.25, 1.

Bioimpedance and the duration of the hemodialysis session.

Bioelectrical impedance analysis (BIA) is composed of resistance (R) and reactance (Xc). The aim of this study was to investigate whether BIA may be influenced by the duration of hemodialysis (HD) sessions. Eleven uremic patients underwent one 4-hour and one 8-hour bicarbonate HD session.

Calcium mass balances during standard bicarbonate hemodialysis and long-hour slow-flow bicarbonate hemodialysis.

Background: Dialysate calcium (Ca) concentration should be viewed as part of the integrated therapeutic regimen to control renal osteodystrophy and maintain normal mineral metabolism. Thus, a correct ionized calcium mass balance (Ca++MB) during hemodialysis (HD) is crucial in the treatment of renal osteodystrophy. The GENIUS single-pass batch dialysis system (Fresenius Medical Care, Germany) consists of a closed dialysate tank of 90 L; it offers the opportunity of effecting mass balances of any solute in a very precise way.

The mckittrick-wheelock syndrome: a rare cause of severe hydroelectrolyte disorders and acute renal failure.

The McKittrick-Wheelock syndrome is a rare cause of severe hydroelectrolyte disorders and fluid depletion as a result of rectal tumor hypersecretion, which can lead to acute renal failure. We report the case of a 70-year-old female who presented with hyponatremia, hypokalemia, hypochloremia, and acute renal failure, due to a watery, mucinous diarrhea. A large rectal villous adenoma was discovered on ileocolonoscopy, and definitive management was achieved by removal of the tumor.

[Uremic toxins: the case of protein-bound compounds].

Uremic retention solutes, if biologically or biochemically active, are called ''uremic toxins''. The retention of these solutes has a negative impact on many functions of the organism, particularly the cardiovascular system. The classification which is applied today is based on the kinetic behavior of the uremic retention solutes during dialysis: 1) small water-soluble molecules (< 500 Daltons); 2) middle molecules (> 500 Daltons); 3) protein-bound compounds.

Removal of uraemic retention solutes in standard bicarbonate haemodialysis and long-hour slow-flow bicarbonate haemodialysis.

Background: Several studies already stressed the importance of haemodialysis (HD) time in the removal of uraemic toxins. In those studies, however, also the amount of dialysate and/or processed blood was altered. The present study aimed to investigate the isolated effect of the factor time t (by processing the same total blood and dialysate volume in two different time schedules) on the removal and kinetic behaviour of some small, middle and protein-bound molecules.

[A case of drug-induced syndrome of inappropriate secretion of antidiuretic hormone].

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is characterized by hyponatremia, plasma hypo-osmolality, a urine sodium concentration >30-40 mmol/L, normal acid-base balance, a normal plasma potassium concentration and, frequently, hypouricemia. There are different types of SIADH: idiopathic, iatrogenic, and forms caused by central nervous system or lung disorders, neoplasia and major surgical interventions. Drug-induced SIADH is becoming the most frequent cause of hyponatremia encountered in clinical practice.

Is there a link between the late occurrence of a brachial artery aneurysm and the ligation of an arteriovenous fistula?

Arteriomegaly and aneurysms proximal to long-standing posttraumatic arteriovenous fistulas (AVF) have been described. Much fewer are the reports of the late occurrence of brachial artery aneurysms following the closure of a hemodialysis AVF. Here, we report the case of a 55-year-old male patient.