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Dialysis access-related distal ischaemia is a rare yet potentially rather risky complication of haemodialysis angioaccess. Timely diagnosis is crucial to target both the goals of the access team: first of all to preserve the function of the hand ideally along with angioaccess patency. Unfortunately for some patients, urgent access ligation and central vein catheter insertion would be needed to save the hand. After a first clinical examination to determine the diagnostic suspicion, the ultrasound evaluation would provide nearly all the needed information to confirm the diagnosis and to determine the most appropriate procedure to rescue the patient from distal ischaemia. In some cases, photoplethysmography would help in the differential diagnosis of other non-ischaemic causes of similar signs and symptoms. Angiography would complete the preoperative evaluation for some. Dialysis access-related distal ischaemia would be briefly reviewed, and a deep description of the ultrasound examination tools and findings would be provided for a tailored therapeutic approach.

Nicola Pirozzi,1 Nicoletta Mancianti,2 Jacopo Scrivano,1 Loredana Fazzari,1 Roberto Pirozzi,1 Matteo Tozzi3 1Interventional Nephrology Unit, Nephrology and Dialysis Department, CdC Nuova ITOR, Roma, Italy; 2Nephrology, Dialysis and Transplant Unit, University Hospital of Siena, Siena, Italy; 3Vascular Surgery, University of Insubria – Asst Settelaghi Varese, Varese, ItalyCorrespondence: Nicola PirozziInterventional Nephrology Unit, Nephrology and Dialysis Department, CdC Nuova ITOR, Via di Pietralata 162, Rome, 00158, ItalyEmail nicola.pirozzi1@gmail.comAbstract: Autogenous radial–cephalic direct wrist arteriovenous fistula (RC-AVF) in the non-dominant arm is the gold standard for dialysis vascular access. However, the RC-AVF non-maturation rate is significant (≃ 40%) due to an increasingly elderly and comorbid population incidence. A detailed identification of the biological cascade underlying arteriovenous fistula (AVF) maturation could be the key to clinical research aimed at identify the group of patients at risk of primary AVF failure. Currently, careful post-operative monitoring remains the most crucial aspect to overcome the problem of impaired maturation. Up to 80% of patients with immature RC-AVF have problems potentially solvable with early endovascular or surgical correction. Physical examination by experienced practitioners in conjunction with duplex ultrasound examination (DUS) can identify physical signs of non-maturation, understand the underlying cause, and drive for a tailored early planning to treat the complication. New approaches for the early assessment of AVF maturation are under study. Techniques to promote RC-AVF maturation performed through the administration of pre-or peri-operative drugs have missed up to now to prove an efficacy in improving fistula success. The new techniques tested after surgery appear to hold future promise for improving fistula maturation.Keywords: arteriovenous fistula maturation, hemodialysis, early failure, rule of six, vascular access

Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon’s experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon’s specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs.

Introduction: Outflow stenosis is a frequent complication of vascular access for hemodialysis. It may cause increased pressure within the angioaccess along with reduced blood flow. Elective treatment is percutaneous transluminal angioplasty; however, when a long occlusion (>2 cm) occurs, success and mid-term patency of endovascular treatment are uncertain. We describe a case series of patients with long occlusion of elbow outflow complicating an otherwise excellent forearm arteriovenous fistula, treated by a bypass across the elbow through cubital vein transposition. Patients and methods: Six consecutive patients have been treated between 2015 and 2017; all were referred because of either low flow, increased venous pressure, excessive bleeding time, or recirculation and were examined by duplex ultrasound. A total of 83% of patients showed associated thrombosis within the access. All procedures were performed under loco-regional anesthesia and preventive hemostasis. Surgical thrombectomy was also performed when needed. Results: Immediate success was obtained in all but two patients converted in veno-venous polytetrafluoroethylene bypass. Post-operative blood flow increased from 316 to 878 mL/min. All patients were dialyzed through the forearm access immediately the day after surgery, without the need for central vein catheter. Overall, 75% of patients needed a percutaneous transluminal angioplasty of the veno-venous anastomosis within 6 months. Primary and secondary patency at 12 and 24 months were 25%–0% and 100%–100%, respectively. Conclusion: Outflow reconstruction through the elbow bypass by cubital vein transposition is a valuable resource to rescue radiocephalic arteriovenous fistula complicated by outflow obstruction, avoiding the use of an interim central vein catheter. Endovascular treatment is vital to maintain functional patency in the mid- and long term.

Recently, a number of reports have described dominant C3 deposits in renal biopsies of patients with infection-related glomerulonephritis (GN). While acute post-infectious GN and membranoproliferative GN are commonly characterized by immune deposits containing C3 and/or C4, the absence of immunoglobulin (Ig) and/or immune complexes at light or electron microscopy is a rather unusual observation. Dominant C3 deposition is believed to result from the alternative pathway of complement activation via the C3bBb "tickover" convertase. The actual occurrence of C3 glomerulopathy could be underestimated, since infection-related GN often quickly subsides without the need for a renal biopsy. A more thorough understanding of the pathways that lead to complement assembly and deposition within the kidney is needed to support a new classification of complement-related lesions, including entities such as dense deposit disease, (atypical) hemolytic-uremic syndrome, dominant C1q, CFHR5, C4d, and C3 glomerulopathies. We will briefly review recent work in this area, focusing on GN with selective complement C3 deposits.

Objective To assess how clinical practice of noninvasive ventilation has evolved in the Italian PICUs. Design National, multicentre, retrospective, observational cohort. Setting Thirteen Italian medical/surgical PICUs that participated in the Italian PICU Network. Patients Seven thousand one-hundred eleven admissions of children with 0-16 years old admitted from January 1, 2011, to December 31, 2012. Interventions None. Measurements and main results Cause of respiratory failure, length and mode of noninvasive ventilation, type of interfaces, incidence of treatment failure, and outcome were recorded. Data were compared with an historical cohort of children enrolled along 6 months from November 1, 2006, to April 30, 2007, over the viral respiratory season. Seven thousand one-hundred eleven PICU admissions were analyzed, and an overall noninvasive ventilation use of 8.8% (n = 630) was observed. Among children who were admitted in the PICU without mechanical ventilation (n = 3,819), noninvasive ventilation was used in 585 patients (15.3%) with a significant increment among the three study years (from 11.6% in 2006 to 18.2% in 2012). In the endotracheally intubated group, 17.2% children received noninvasive ventilation at the end of the weaning process to avoid reintubation: 11.9% in 2006, 15.3% in 2011, and 21.6% in 2012. Noninvasive ventilation failure rate raised from 10% in 2006 to 16.1% in 2012. Conclusions Noninvasive ventilation is increasingly and successfully used as first respiratory approach in several, but not all, Italian PICUs. The current study shows that noninvasive ventilation represents a feasible and safe technique of ventilatory assistance for the treatment of mild acute respiratory failure. Noninvasive ventilation was used as primary mode of ventilation in children with low respiratory tract infection (mainly in bronchiolitis and pneumonia), in acute on chronic respiratory failure or to prevent reintubation.

Purpose The purpose of this study is to report surgical techniques to facilitate cannulation of deep matured veins. Methods and Results 1) Basilic vein tunnel superficialization with rerouting in an anterior tunnel is mandatory for brachial-basilic arteriovenous fistula (AVF), mostly performed in a second surgical stage. The elevation technique, which could necessitate cannulation of the vein through the overlying scar, is not advisable. 2) Femoral vein superficialization is a one-stage surgical operation. Complications of this high-flow AVF are distal ischemia (diabetes and occlusive arterial disease are contraindications), iliac vein stenosis due to intimal hypertrophy and cardiac issues. Nevertheless, we have achieved high long-term patency rates (N = 70). Primary patency rates at 1 and 9 years were 91% ± 4% and 45% ± 11%, respectively. Secondary patency rates at 1 and 9 years were 84% ± 5% and 56% ± 9%, respectively. 3) Lipectomy for superficialization of the forearm radial-cephalic AVF is described for obese patients. Subcutaneous tissues are resected using two transverse incisions. Mobilization of the vein is avoided. At 3 years (N = 49), we recorded 63% ± 8% and 88% ± 7% primary and secondary patency rates, respectively. Anterior transposition of the forearm basilic vein is not necessary when using microsurgery for creation of distal ulno-basilic AVF. 4) VWING is a novel surgically implanted device to help buttonhole technique cannulation. It is too early to draw any conclusion from the preliminary published reports. Conclusions Tunnel-transposition and lipectomy are efficient techniques to allow easy needling of deeply situated upper-arm basilic vein, and cephalic vein in obese patients, respectively.

Progressive renal fibrosis is a common outcome of almost all forms of renal damage, including diabetic nephropathy. Fibrosis leads to chronic kidney failure and, eventually, dialysis or transplantation (1–3). Although much is known about the molecular background and mediators that prompt fibroblasts or transdifferentiated kidney cells to release collagen and matrix (4–6), the search for a unique event that initiates the process remains inconclusive. Targeting this putative key signal would enable researchers to “switch off” fibrosis and, perhaps, the progressive loss of renal function that plagues millions of individuals worldwide (1–6). The intermediate/small-conductance Ca2+-activated K+ channel (KCa3.1; KCNN4; SK4) is one intriguing candidate for such function because it promotes fibrogenesis in target tissue by altering the membrane potential of cells, thus enhancing extracellular Ca2+ entry (7,8). Subsequent Smad2/3 or mitogen-activated protein kinase (MEK)–dependent phosphorylation upregulates profibrotic genes and collagens in human and animal fibroblasts (7–9). KCa3.1 Ca2+-activated channels regulate K+ outflow, increasing the driving force for Ca2+ entry through hyperpolarization of the plasma membrane (7,10). In KCa3.1, four identical subunits are gathered as a symmetric homotetramer. Six hydrophobic α-helical domains are inserted into the cell membrane in each subunit (Fig. 1). A five-residue loop between the fifth and sixth transmembrane domain confers K+ selectivity. K+ channels are usually tightly associated with calmodulin, the regulatory protein that accounts for the Ca2+ sensitivity of these channels, usually activated by [Ca2+] …

Surgical reinterventions for treatment of complications or ligation of haemodialysis vascular access (VA), when performed in or below the mid/lower part of the upper arm, could benefit from the use of preventive haemostasis with an inflatable tourniquet. This technique offers several advantages, such as the reduced risk of bleeding and the increased accuracy of dissection allowing for a minimally invasive approach. The use of preventive haemostasis is safe, economical and time-saving. All the secondary procedures on VA that could benefit from its use are reviewed.

In critically ill adults, a reduction in the extravascular lung water index (EVLWi) decreases time on mechanical ventilation and improves survival. The purpose of this study is to assess the prognostic value of EVLWi in critically ill children with acute respiratory failure and investigate its relationships with PaO(2), PaO(2)/FiO(2) ratio, A-aDO(2), oxygenation index (OI), mean airway pressure, cardiac index, pulmonary permeability, and percent fluid overload.Twenty-seven children admitted to PICU with acute respiratory failure received volumetric hemodynamic and blood gas monitoring following initial stabilization and every 4 h thereafter, until discharge from PICU or death. All patients are grouped in two categories: nonsurvivors and survivors.Children with a fatal outcome had higher values of EVLWi on admission to PICU, as well as higher A-aDO(2) and OI, and lower PaO(2) and PaO(2)/FIO(2) ratio. After 24 h EVLWi decreased significantly only in survivors. As a survival indicator, EVLWi has good sensitivity and good specificity. Changes in EVLWi, OI, and mean airway pressure had a time-dependent influence on survival that proved significant according to the Cox test. Survivors spent fewer hours on mechanical ventilation. We detected a correlation of EVLWi with percent fluid overload and pulmonary permeability.Like OI and mean airway pressure, EVLWi on admission to PICU is predictive of survival and of time needed on mechanical ventilation.

BACKGROUND: Preoperative renal function is an important risk factor in cardiac surgery for long-term and short-term outcomes. Renal function is best assessed by measuring or calculating the glomerular filtration rate (GFR). Several algorithms using the endogenous marker serum creatinine have been developed to estimate renal function. These include the Cockcroft and Gault and the modification of diet in renal disease (MDRD) formulae. The aim of this study was to compare the predictive power of the two formulae towards short-term outcomes after cardiac surgery, such as the length of intensive care unit (ICU) stay, the length of mechanical ventilation time, and the length of in-hospital stay. METHODS: One hundred and fifty patients undergoing cardiac surgery and not affected by renal failure were followed up until hospital discharge. We collected data before, during and after surgery. Before surgery data consisted of date of birth, sex, height, weight, plasma creatinine level; during surgery data consisted of type of intervention (including number of bypasses, if any), cardiopulmonary bypass time and aortic cross-clamp time; after surgery data consisted of length of ICU stay, mechanical ventilation time, length of in-hospital stay after intensive-care discharge (ward stay), incidence of acute renal failure (expressed as the need for dialysis) and mortality. The dataset was analyzed using Cox regression. RESULTS: The average mechanical ventilation time, ICU stay and ward stay were 11 h, 49 h and 10 days, respectively. After having adjusted for chronic obstructive pulmonary disease, diabetes and postsurgical dialysis, the GFR calculated with the Cockcroft and Gault formula appeared to be a predictor of ICU stay and mechanical ventilation time with very strong evidence (P = 0.002 and

The syndrome of inappropriate ADH secretion (SIADH), also recently referred to as the "syndrome of inappropriate antidiuresis", is an often underdiagnosed cause of hypotonic hyponatremia, resulting for instance from ectopic release of ADH in lung cancer or as a side-effect of various drugs. In SIADH, hyponatremia results from a pure disorder of water handling by the kidney, whereas external Na+ balance is usually well regulated. Despite increased total body water, only minor changes of urine output and modest edema are usually seen. Renal function and acid-base balance are often preserved, while neurological impairment may range from subclinical to life-threatening. Hypouricemia is a distinguishing feature. The major causes and clinical variants of SIADH are reviewed, with particular emphasis on iatrogenic complications and hospital-acquired hyponatremia. Effective treatment of SIADH with water restriction, aquaretics, or hypertonic saline + loop diuretics, as opposed to worsening of hyponatremia during parenteral isotonic fluid administration, underscores the importance of an early accurate diagnosis and careful follow-up of these patients.

Introduction Independent lung ventilation is a form of protective ventilation strategy used in adult asymmetric acute lung injury, where the application of conventional mechanical ventilation can produce ventilator-induced lung injury and ventilation-perfusion mismatch. Only a few experiences have been published on the use of independent lung ventilation in newborn patients. Case presentation We present a case of independent lung ventilation in a 16-day-old infant of 3.5 kg body weight who had an asymmetric lung injury due to respiratory syncytial virus bronchiolitis. We used independent lung ventilation applying conventional protective pressure controlled ventilation to the less-compromised lung, with a respiratory frequency proportional to the age of the patient, and a pressure controlled high-frequency ventilation to the atelectatic lung. This was done because a single tube conventional ventilation protective strategy would have exposed the less-compromised lung to a high mean airways pressure. The target of independent lung ventilation is to provide adequate gas exchange at a safe mean airways pressure level and to expand the atelectatic lung. Independent lung ventilation was accomplished for 24 hours. Daily chest radiograph and gas exchange were used to evaluate the efficacy of independent lung ventilation. Extubation was performed after 48 hours of conventional single-tube mechanical ventilation following independent lung ventilation. Conclusion This case report demonstrates the feasibility of independent lung ventilation with two separate tubes in neonates as a treatment of an asymmetric acute lung injury.

Recent studies reported that real-time ultrasound guidance for internal jugular vein catheterization is useful in infants. However, this technique is sometimes difficult even for skilled physicians. The aim of our study is therefore to evaluate the success rate and the complication rate of this technique performed by ultrasound-trained pediatric intensivists in neonates.

Background Mortality rate of patients admitted to Intensive Care Units is a widely adopted outcome indicator. Because of large case-mix variability, comparisons of mortality rates must be adjusted for the severity of patient illness at admission. The Pediatric Index of Mortality 2 (PIM-2) has been widely adopted as a tool for adjusting mortality rate by patients’ case mix. The objective of this study was to assess the performance of PIM-2 in children admitted to intensive care units after cardiac surgery, other surgery, or for other reasons. Methods This was a prospective cohort study, conducted in a 607 inpatient-bed tertiary-care pediatric hospital in Italy, with three pediatric intensive care Units (PICUs) and one cardiac Unit (CICU). In 2009–11, all consecutive admissions to PICUs/CICU of children aged 0–16 years were included in the study. Discrimination and calibration measures were computed to assess PIM-2 performance. Multivariable logistic regression analysis was used to assess the association of patients’ main reason for intensive care admission (cardiac-surgical, other-surgical, medical), age, Unit and year with observed mortality, adjusting for PIM-2 score. Results PIM-2 data collection was completed for 91.2% of total PICUs/CICU patient admissions (2912), and for 94.8% of patients who died in PICUs/CICU (129). Overall observed mortality was 4.4% (95% CI, 3.7-5.2), compared to 6.4% (95% CI, 5.5-7.3) expected mortality. Standardised mortality ratio was 0.7 (95% CI: 0.6-0.8). PIM-2 discrimination was fair (area under the curve, 0.79; 95% CI: 0.75-0.83). Calibration was less satisfactory, mainly because of the over two-fold overprediction of deaths in the highest risk group (114.7 vs 53; p