Nosocomial infections in dialysis access.

Nosocomial infections in patients requiring renal replacement therapy have a high impact on morbidity and mortality. The most dangerous complication is bloodstream infection (BSI) associated with the vascular access, with a low BSI risk in arteriovenous fistulas or grafts and a comparatively high risk in central venous catheters. The single most important measure for preventing BSI is therefore the reduction of catheter use by means of early fistula formation. As this is not always feasible, prevention should focus on educational efforts, hand hygiene, surveillance of dialysis-associated events, and specific measures at and after the insertion of catheters. Core measures at the time of insertion include choosing the optimal site of insertion, the use of maximum sterile barrier precautions, adequate skin antisepsis, and the choice of catheter type; after insertion, access care needs to ensure hub disinfection and regular dressing changes. The application of antimicrobial locks is reserved for special situations. Evidence suggests that bundling a selection of the aforementioned measures can significantly reduce infection rates. The diagnosis of central line-associated BSI (CLABSI) is based on clinical signs and microbiological findings in blood cultures ideally drawn both peripherally and from the catheter. The prompt installation of empiric antibiotic treatment covering the most commonly encountered organisms is key regarding CLABSI treatment. Catheter removal is recommended in complicated cases or if cultures yield Staphylococcus aureus, enterococci, Pseudomonas or fungi. In other cases, guide wire exchange or catheter salvage strategies with antibiotic lock solutions may be acceptable alternatives.

Changes in Left Ventricular Torsion Early Postoperatively After Aortic Valve Replacement and at Long-Term Follow-up.

OBJECTIVE In patients with aortic stenosis, left ventricular systolic torsion (pT) is increased to overcome excessive afterload. This study assessed left ventricular torsion before and immediately after surgical valve replacement and tested the instant effect of fluid loading. DESIGN Prospective, clinical single-center study. SETTING Intensive care unit of a university hospital. PARTICIPANTS 12 patients undergoing elective aortic valve replacement for aortic stenosis. INTERVENTIONS Echocardiography was performed on the day before surgery, within 18 hours after surgery including a fluid challenge, and after 2.5 years. MEASUREMENTS AND MAIN RESULTS pT decreased early postoperatively by 21.2% (23.4° ± 5.6° to 18.4° ± 6.9°; p = 0.012) and reached preoperative values at 2.5 years follow-up (24 ± 7). Peak diastolic untwisting velocity occurred later early postoperatively (13% ± 8% to 21% ± 9.4%; p = 0.019) and returned toward preoperative values at follow-up (10.2 ± 4.7°). The fluid challenge increased central venous pressure (8 ± 4 mmHg to 11 ± 4 mmHg; p = 0.003) and reduced peak systolic torsion velocity (138.7 ± 37.6/s to 121.3 ± 32/s; p = 0.032). pT decreased in 3 and increased in 8 patients after fluid loading. Patients whose pT increased had higher early mitral inflow velocity postoperatively (p = 0.04) than those with decreasing pT. Patients with reduced pT after fluid loading received more fluids (p = 0.04) and had a higher positive fluid balance during the intensive care unit stay (p = 0.03). Torsion after fluid loading correlated with total fluid input (p = 0.001) and cumulative fluid balance (p = 0.002). CONCLUSIONS pT decreased early after aortic valve replacement but remained elevated despite elimination of aortic stenosis. After 2.5 years, torsion had returned to preoperative levels.

Nierenersatzverfahren – gestern, heute und morgen

Die Nierenersatztherapie ist eine der erfolgreichsten Geschichten eines künstlichen Organersatzes. Der vorliegende Artikel beschreibt die wichtigsten Schritte in der Evolution zur modernen Therapie mit Peritonealdialyse und Hämodialyse. Aktuelle Fragen im Bereich der Nierenersatztherapie werden diskutiert und zukünftige Entwicklungen aufgezeigt. Dem Patienten stehen heute diverse Therapiemöglichkeiten offen. Allerdings nur, wenn er mindestens ein halbes Jahr vor der Notwendigkeit eines Therapiebeginns die für ihn ideale Therapieform auswählen kann. Verspätete Zuweisungen und die Notwendigkeit eines akuten Dialysebeginns führen nicht nur zu einer erhöhten Mortalität, sondern auch dazu, dass eine präemptive Lebendnierentransplantation verunmöglicht wird. Zudem bleiben diese Patienten in der Regel im Dialysezentrum und können für eine Heimbehandlung, sei es nun in Form einer Peritonealdialyse oder Heimhämodialyse, nicht mehr motiviert werden.

Neuartiger knochenverankerter Hämodialysezugang

Für Patienten an der Hämodialyse ist nach Versagen der klassischen arterio-venösen Fisteln oder Shunts ein direkter Gefässzugang mittels Katheter lebensnotwendig. Permanente zentralvenöse Katheter penetrieren die Hals- und Thoraxweichteile und die Haut ohne rigide Befestigung. Die Infektionsrate ist hoch und führt oft zur Explantation. Knochenverankerte Hörgeräte sind zur Behandlung bei Schalleitungsschwerhörigkeit etabliert. Das Implantat sitzt fest im Felsenbein und der Aufsatz penetriert die Haut. Schwere Infektionen, die eine Explantation nötig machen, sind sehr selten. Wir nehmen an, dass einer der Hauptgründe für die tiefe Komplikationsrate die starke Befestigung des Implantats am Knochen ist, wodurch die Hautbewegungen relativ zum Knochen minimiert werden. Basierend auf den Erfahrungen mit implantierten Hörsystemen haben wir einen perkutanen knochenverankerten Hämodialysezugang im Bereich des Felsenbeins als vorteilhafte Alternative zum herkömmlichen zentralvenösen Katheterzugang entwickelt. Dabei wurde die Felsenbeinanatomie und Knochendicke zur Lokalisierung des idealen Implantationsortes untersucht; die Schraubenstabilität im Knochen getestet; ein Titanimplantat inklusive Ventile und Katheter, sowie chirurgische Instrumente zur sicheren Implantation entwickelt. Der knochenverankerte Hämodialysezugang wurde auf Flussrate, Dichtigkeit und Reinigung getestet; die Platzierung des Katheters mittels Seldingertechnik in die V. jugularis interna über eine Halsinzision festgelegt. Die Resultate unserer Arbeit zeigen die technische Machbarkeit eines im Felsenbein verankerten neuartigen Hämodialysezuganges und bilden die Grundlage einer inzwischen bewilligten klinischen Pilotstudie.

Bloodstream infection in paediatric cancer centres--leukaemia and relapsed malignancies are independent risk factors.

UNLABELLED In a prospective multicentre study of bloodstream infection (BSI) from November 01, 2007 to July 31, 2010, seven paediatric cancer centres (PCC) from Germany and one from Switzerland included 770 paediatric cancer patients (58% males; median age 8.3 years, interquartile range (IQR) 3.8-14.8 years) comprising 153,193 individual days of surveillance (in- and outpatient days during intensive treatment). Broviac catheters were used in 63% of all patients and Ports in 20%. One hundred forty-two patients (18%; 95% CI 16 to 21%) experienced at least one BSI (179 BSIs in total; bacteraemia 70%, bacterial sepsis 27%, candidaemia 2%). In 57%, the BSI occurred in inpatients, in 79% after conventional chemotherapy. Only 56 % of the patients showed neutropenia at BSI onset. Eventually, patients with acute lymphoblastic leukaemia (ALL) or acute myeloblastic leukaemia (AML), relapsed malignancy and patients with a Broviac faced an increased risk of BSI in the multivariate analysis. Relapsed malignancy (16%) was an independent risk factor for all BSI and for Gram-positive BSI. CONCLUSION This study confirms relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. On a unit level, data on BSIs in this high-risk population derived from prospective surveillance are not only mandatory to decide on empiric antimicrobial treatment but also beneficial in planning and evaluating preventive bundles. WHAT IS KNOWN • Paediatric cancer patients face an increased risk of nosocomial bloodstream infections (BSIs). • In most cases, these BSIs are associated with the use of a long-term central venous catheter (Broviac, Port), severe and prolonged immunosuppression (e.g. neutropenia) and other chemotherapy-induced alterations of host defence mechanisms (e.g. mucositis). What is New: • This study is the first multicentre study confirming relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. • It describes the epidemiology of nosocomial BSI in paediatric cancer patients mainly outside the stem cell transplantation setting during conventional intensive therapy and argues for prospective surveillance programmes to target and evaluate preventive bundle interventions.

A standardized protocol for the prevention of clinically relevant venous air embolism during neurosurgical interventions in the semisitting position

OBJECTIVE: We report the results and complications associated with standardized intraoperative management designed for the prevention of hemodynamically relevant venous air embolism during surgery performed in the semisitting position. METHODS: A protocol for preoperative evaluation and intraoperative monitoring was developed and applied in 187 consecutive patients who underwent surgery in the semisitting position between 1999 and 2004. The protocol included preoperative transesophageal echocardiography examination (TEE), intraoperative TEE monitoring, catheterization of the right atrium and a combination of fluid input, positive end expiratory pressure, and standardized positioning aiming at a positive pressure in the transverse and sigmoid sinuses. Data were collected retrospectively from the charts and intraoperative anesthesiological protocols of the patients for the incidence of clinically relevant air embolism (i.e., TEE-diagnosed air embolism plus a decrease in end tidal CO2 or hemodynamic changes) and other complications related to the semisitting position. RESULTS: Three cases (1.6%) of relevant venous air embolism occurred in 187 patients. Only 1 case (0.5%) was hemodynamically relevant, with temporary arterial blood pressure decrease and heart rate increase. Pneumatocephalus leading to lethargy was a frequent postoperative finding, which resolved spontaneously in all except 1 patient with epileptic seizure and oculomotor nerve palsy attributable to space-occupying subdurally trapped air, which had to be treated surgically. There was no permanent morbidity or mortality related to the semisitting position. CONCLUSION: Fear of massive venous air embolism is one reason for dramatic decline in the use of the semisitting position in neurosurgical practice. We found that strict adherence to a standardized protocol using TEE monitoring before and during surgery; exclusion of patients with patent foramen ovale; and a combination of positive end expiratory pressure, fluid input, and a standardized position aiming a positive pressure in the transverse and sigmoid sinuses helped to greatly minimize this complication to a rate of 0.5% for hemodynamically relevant events.

Design and establishment of a biobank in a multicenter prospective cohort study of elderly patients with venous thromboembolism (SWITCO65+)

In the field of thrombosis and haemostasis, many preanalytical variables influence the results of coagulation assays and measures to limit potential results variations should be taken. To our knowledge, no paper describing the development and maintenance of a haemostasis biobank has been previously published. Our description of the biobank of the Swiss cohort of elderly patients with venous thromboembolism (SWITCO65+) is intended to facilitate the set-up of other biobanks in the field of thrombosis and haemostasis. SWITCO65+ is a multicentre cohort that prospectively enrolled consecutive patients aged ≥65 years with venous thromboembolism at nine Swiss hospitals from 09/2009 to 03/2012. Patients will be followed up until December 2013. The cohort includes a biobank with biological material from each participant taken at baseline and after 12 months of follow-up. Whole blood from all participants is assayed with a standard haematology panel, for which fresh samples are required. Two buffy coat vials, one PAXgene Blood RNA System tube and one EDTA-whole blood sample are also collected at baseline for RNA/DNA extraction. Blood samples are processed and vialed within 1 h of collection and transported in batches to a central laboratory where they are stored in ultra-low temperature archives. All analyses of the same type are performed in the same laboratory in batches. Using multiple core laboratories increased the speed of sample analyses and reduced storage time. After recruiting, processing and analyzing the blood of more than 1,000 patients, we determined that the adopted methods and technologies were fit-for-purpose and robust.

Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy.

BACKGROUND Venous thromboembolism (VTE) often complicates the clinical course of cancer. The risk is further increased by chemotherapy, but the safety and efficacy of primary thromboprophylaxis in cancer patients treated with chemotherapy is uncertain. This is an update of a review first published in February 2012. OBJECTIVES To assess the efficacy and safety of primary thromboprophylaxis for VTE in ambulatory cancer patients receiving chemotherapy compared with placebo or no thromboprophylaxis. SEARCH METHODS For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013), CENTRAL (2013, Issue 5), and clinical trials registries (up to June 2013). SELECTION CRITERIA Randomised controlled trials (RCTs) comparing any oral or parenteral anticoagulant or mechanical intervention to no intervention or placebo, or comparing two different anticoagulants. DATA COLLECTION AND ANALYSIS Data were extracted on methodological quality, patients, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively. MAIN RESULTS We identified 12 additional RCTs (6323 patients) in the updated search so that this update considered 21 trials with a total of 9861 patients, all evaluating pharmacological interventions and performed mainly in patients with advanced cancer. Overall, the risk of bias varied from low to high. One large trial of 3212 patients found a 64% (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.22 to 0.60) reduction of symptomatic VTE with the ultra-low molecular weight heparin (uLMWH) semuloparin relative to placebo, with no apparent difference in major bleeding (RR 1.05, 95% CI 0.55 to 2.00). LMWH, when compared with inactive control, significantly reduced the incidence of symptomatic VTE (RR 0.53, 95% CI 0.38 to 0.75; no heterogeneity, Tau(2) = 0%) with similar rates of major bleeding events (RR 1.30, 95% CI 0.75 to 2.23). In patients with multiple myeloma, LMWH was associated with a significant reduction in symptomatic VTE when compared with the vitamin K antagonist warfarin (RR 0.33, 95% CI 0.14 to 0.83), while the difference between LMWH and aspirin was not statistically significant (RR 0.51, 95% CI 0.22 to 1.17). No major bleeding was observed in the patients treated with LMWH or warfarin and in less than 1% of those treated with aspirin. Only one study evaluated unfractionated heparin against inactive control and found an incidence of major bleeding of 1% in both study groups while not reporting on VTE. When compared with placebo, warfarin was associated with a statistically insignificant reduction of symptomatic VTE (RR 0.15, 95% CI 0.02 to 1.20). Antithrombin, evaluated in one study involving paediatric patients, had no significant effect on VTE nor major bleeding when compared with inactive control. The new oral factor Xa inhibitor apixaban was evaluated in a phase-II dose finding study that suggested a promising low rate of major bleeding (2.1% versus 3.3%) and symptomatic VTE (1.1% versus 10%) in comparison with placebo. AUTHORS' CONCLUSIONS In this update, we confirmed that primary thromboprophylaxis with LMWH significantly reduced the incidence of symptomatic VTE in ambulatory cancer patients treated with chemotherapy. In addition, the uLMWH semuloparin significantly reduced the incidence of symptomatic VTE. However, the broad confidence intervals around the estimates for major bleeding suggest caution in the use of anticoagulation and mandate additional studies to determine the risk to benefit ratio of anticoagulants in this setting. Despite the encouraging results of this review, routine prophylaxis in ambulatory cancer patients cannot be recommended before safety issues are adequately addressed.

Primary prophylaxis for venous thromboembolism in patients undergoing cardiac or thoracic surgery.

BACKGROUND Cardiac and thoracic surgery are associated with an increased risk of venous thromboembolism (VTE). The safety and efficacy of primary thromboprophylaxis in patients undergoing these types of surgery is uncertain. OBJECTIVES To assess the effects of primary thromboprophylaxis on the incidence of symptomatic VTE and major bleeding in patients undergoing cardiac or thoracic surgery. SEARCH METHODS The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2014) and CENTRAL (2014, Issue 4). The authors searched the reference lists of relevant studies, conference proceedings, and clinical trial registries. SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs comparing any oral or parenteral anticoagulant or mechanical intervention to no intervention or placebo, or comparing two different anticoagulants. DATA COLLECTION AND ANALYSIS We extracted data on methodological quality, participant characteristics, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively. MAIN RESULTS We identified 12 RCTs and one quasi-RCT (6923 participants), six for cardiac surgery (3359 participants) and seven for thoracic surgery (3564 participants). No study evaluated fondaparinux, the new oral direct thrombin, direct factor Xa inhibitors, or caval filters. All studies had major study design flaws and most lacked a placebo or no treatment control group. We typically graded the quality of the overall body of evidence for the various outcomes and comparisons as low, due to imprecise estimates of effect and risk of bias. We could not pool data because of the different comparisons and the lack of data. In cardiac surgery, 71 symptomatic VTEs occurred in 3040 participants from four studies. In a study of 2551 participants, representing 85% of the review population in cardiac surgery, the combination of unfractionated heparin with pneumatic compression stockings was associated with a 61% reduction of symptomatic VTE compared to unfractionated heparin alone (1.5% versus 4.0%; risk ratio (RR) 0.39; 95% confidence interval (CI) 0.23 to 0.64). Major bleeding was only reported in one study, which found a higher incidence with vitamin K antagonists compared to platelet inhibitors (11.3% versus 1.6%, RR 7.06; 95% CI 1.64 to 30.40). In thoracic surgery, 15 symptomatic VTEs occurred in 2890 participants from six studies. In the largest study evaluating unfractionated heparin versus an inactive control the rates of symptomatic VTE were 0.7% versus 0%, respectively, giving a RR of 6.71 (95% CI 0.40 to 112.65). There was insufficient evidence to determine if there was a difference in the risk of major bleeding from two studies evaluating fixed-dose versus weight-adjusted low molecular weight heparin (2.7% versus 8.1%, RR 0.33; 95% CI 0.07 to 1.60) and unfractionated heparin versus low molecular weight heparin (6% and 4%, RR 1.50; 95% CI 0.26 to 8.60). AUTHORS' CONCLUSIONS The evidence regarding the efficacy and safety of thromboprophylaxis in cardiac and thoracic surgery is limited. Data for important outcomes such as pulmonary embolism or major bleeding were often lacking. Given the uncertainties around the benefit-to-risk balance, no conclusions can be drawn and a case-by-case risk evaluation of VTE and bleeding remains preferable.