Strategies to Reduce Hemodialysis Catheter-related Complications

The objective of the studies presented in this thesis was to reduce hemodialysis catheter-related complications by studying the influence of the following issues. In Chapter 3 we address the best cannulation site once the time period a hemodialysis catheter is needed has been estimated. We showed that untunneled femoral catheters should not be left in place for more than 5-7 days because of the high risk of infections. We also demonstrated that untunneled jugular catheters used for more than 3 weeks give high infection rates and the use of an untunneled jugular catheter should be preferred when a catheter is needed for the longer time periods. In Chapter 4 we describe that a novel design untunneled jugular catheter can reduce catheter-related complications and can be used safely for a time period of three months. In Chapter 5 we describe the construction and potential flaws in the manufacturing process from a fractured silicone hemodialysis catheter by performing an extensive scanning electron microscopy study and using energy-dispersive X-ray spectral analysis to determine the components of the catheter. The geometry, tip design of catheters and the application of side-holes have been determined mainly by methods of trial and error. In the second study presented in Chapter 5 we performed an in vitro study on the fluid dynamics of four different types of tunneled and untunneled catheters and demonstrated that side holes should not be used in catheters. Catheters have to be locked with a solution for the interdialytic period. It is well known that locking solutions leak out from the tip of the catheter, but the clinical implications of this feature are not clear. Traditionally, heparin is installed but there are no studies to support this practice. Local acting antimicrobial locking solutions could be an attractive alternative. Low and high concentrations of trisodium citrate (TSC) have been advocated. In Chapter 6 we describe the antimicrobial properties of 4 different concentrations of TSC in vitro, using two classical antimicrobial susceptibility tests and showed that 30% TSC is the optimal concentration for a catheter locking solution to be used in a multicenter double blind randomised controlled trial. The outcome of this trial is described in the second part of Chapter 6. In this study we compared heparin with TSC and showed an important reduction in infectious complications. We also demonstrated a reduction in bleeding complications in patients that had TSC installed in their catheter.Wee, P.M. ter [Promotor

Cognitive coping, goal adjustment, and depressive and anxiety symptoms in people undergoing infertility treatment:a prospective study

The relationships between cognitive coping strategies, goal adjustment, and symptoms of depression and anxiety were studied in people with fertility problems. Both cross-sectional and prospective relationships were studied in a sample of 313 patients attending an infertility clinic. Self-report questionnaires were filled out at home. Positive refocusing, rumination and catastrophizing, and goal reengagement were related to symptoms of depression and anxiety. When looking at the long-term effects, rumination and catastrophizing were also related to emotional problems nine months later. These findings suggest that intervention programs should focus on cognitive coping strategies and goal-based processe

Bismuth coating of non-tunneled haemodialysis catheters reduces bacterial colonization: a randomized controlled trial

Background. Haemodialysis (HD) catheter-related blood stream infections are a major cause of morbidity and mortality in patients with acute and chronic renal failure

Microbial inactivation properties of a new antimicrobial/antithrombotic catheter lock solution (citrate/methylene blue/parabens)

Background. Microbial infections are the most serious complications associated with indwelling central venous catheters. A catheter lock solution that is both antibacterial and antithrombotic is needed. The goal of this study was to determine whether a new catheter lock solution containing citrate, methylene blue and parabens has antimicrobial properties against planktonic bacteria and against sessile bacteria within a biofilm. These effects were compared to the antimicrobial properties of heparin at 2500 units/ml

Prevention of catheter lumen occlusion with rT-PA versus heparin (Pre-CLOT): study protocol of a randomized trial [ISRCTN35253449]

BACKGROUND: Many patients with end-stage renal disease use a central venous catheter for hemodialysis access. A large majority of these catheters malfunction within one year of insertion, with up to two-thirds due to thrombosis. The optimal solution for locking the catheter between hemodialysis sessions, to decrease the risk of thrombosis and catheter malfunction, is unknown. The Prevention of Catheter Lumen Occlusion with rt-PA versus Heparin (PreCLOT) study will determine if use of weekly rt-PA, compared to regular heparin, as a catheter locking solution, will decrease the risk of catheter malfunction. METHODS/DESIGN: The study population will consist of patients requiring chronic hemodialysis thrice weekly who are dialyzed with a newly inserted permanent dual-lumen central venous catheter. Patients randomized to the treatment arm will receive rt-PA 1 mg per lumen once per week, with heparin 5,000 units per ml as a catheter locking solution for the remaining two sessions. Patients randomized to the control arm will receive heparin 5,000 units per ml as a catheter locking solution after each dialysis session. The study treatment period will be six months, with 340 patients to be recruited from 14 sites across Canada. The primary outcome will be catheter malfunction, based on mean blood flow parameters while on hemodialysis, with a secondary outcome of catheter-related bacteremia. A cost-effectiveness analysis will be undertaken to assess the cost of maintaining a catheter using rt-PA as a locking solution, compared to the use of heparin. DISCUSSION: Results from this study will determine if use of weekly rt-PA, compared to heparin, will decrease catheter malfunction, as well as assess the cost-effectiveness of these locking solutions

Precurved non-tunnelled catheters for haemodialysis are comparable in terms of infections and malfunction as compared to tunnelled catheters: A retrospective cohort study

Background: The main limitations of central venous catheters for haemodialysis access are infections and catheter malfunction. Our objective was to assess whether precurved non-tunnelled central venous catheters are comparable to tunnelled central venous catheters in terms of infection and catheter malfunction and to assess whether precurved non-tunnelled catheters are superior to straight catheters. Materials and methods: In this retrospective, observational cohort study, adult patients in whom a central venous catheter for haemodialysis was inserted between 2012 and 2016 were included. The primary endpoint was a combined endpoint consisting of the first occurrence of either an infection or catheter malfunction. The secondary endpoint was a combined endpoint of the removal of the central venous catheter due to either an infection or a catheter malfunction. Using multivariable analysis, cause-specific hazard ratios for endpoints were calculated for tunnelled catheter versus precurved non-tunnelled catheter, tunnelled catheter versus non-tunnelled catheter, and precurved versus straight nontunnelled catheter. Results: A total of 1603 patients were included. No difference in reaching the primary endpoint was seen between tunnelled catheters, compared to precurved non-tunnelled catheters (hazard ratio, 0.91; 95% confidence interval, 0.70– 1.19, p=0.48). Tunnelled catheters were removed less often, compared to precurved non-tunnelled catheters (hazard ratio, 0.65; 9

Heparin versus 0.9% sodium chloride intermittent flushing for prevention of occlusion in central venous catheters in adults

Background Heparin intermittent flushing is a standard practice in the maintenance of patency in central venous catheters. However, we could find no systematic review examining its effectiveness and safety. Objectives To assess the effectiveness of intermittent flushing with heparin versus 0.9% sodium chloride (normal saline) solution in adults with central venous catheters in terms of prevention of occlusion and overall benefits versus harms. Search methods The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched December 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11). Searches were also carried out in MEDLINE, EMBASE, CINAHL and clinical trials databases (December 2013). Selection criteria Randomised controlled trials (RCTs) in adults 18 years of age and older with a central venous catheter (CVC) in which intermittent flushing with heparin (any dose with or without other drugs) was compared with 0.9% normal saline were included. No restriction on language was applied. Data collection and analysis Two review authors independently selected trials, assessed trial quality and extracted data. Trial authors were contacted to retrieve additional information, when necessary. Main results Six eligible studies with a total of 1433 participants were included. The heparin concentrations used in these studies were very different (10-5000 IU/mL), and follow-up varied from 20 days to 180 days. The overall risk of bias in the studies was low. The quality of the evidence ranged from very low to moderate for the main outcomes (occlusion of CVC, duration of catheter patency, CVC-related sepsis, mortality and haemorrhage at any site). Combined findings from three trials in which the unit of analysis was the catheter suggest that heparin was associated with reduced CVC occlusion rates (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.29 to 0.94). However, no clear evidence of a similar effect was found when the results of two studies in which the unit of analysis was the participant were combined (RR 0.21, 95% CI 0.03 to 1.70), nor when findings were derived from one study, which considered total line accesses (RR 1.08, 95% CI 0.84 to 1.40). Furthermore, results for other estimated effects were found to be imprecise and compatible with benefit and harm: catheter duration in days (mean difference (MD) 0.41, 95% CI -1.29 to 2.12), CVC-related thrombosis (RR 1.22, 95% CI 0.74 to 1.99), CVC-related sepsis (RR 1.02, 95% CI 0.34 to 3.03), mortality (RR 0.77, 95% CI 0.45 to 1.32) and haemorrhage at any site (RR 1.37, 95% CI 0.49 to 3.85). Authors' conclusions We found no conclusive evidence of important differences when heparin intermittent flushing was compared with 0.9% normal saline flushing for central venous catheter maintenance in terms of efficacy or safety. As heparin is more expensive than normal saline, our findings challenge its continued use in CVC flushing outside the context of clinical trials

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This dissertation concerns national heritage management as it is performed as an established institutional practice and a politically defined engagement. Since the late 1990´s an overarching political objective has been to ensure “everyone’s participation in heritage and heritage management” (Gov. bill 1997/98:114, 2012/13:96). Even though participation and inclusive practices continue to be urgent issues in policymaking – both nationally and internationally – a series of unsolved questions can be identified on how a negotiation of established engagements should be implemented, carried out and handled. The aim of this research is to analyse how participation as a political objective has been governed, interpreted and put into practice by public heritage actors in Sweden during the time period between 1997 and 2017. Based in the context of critical heritage studies the research seeks to unravel a series of different aspects; such as the relations between actorhood and institutionalised practices, the interaction and positions for influence, and lastly, claims on heritage and ability to highlight an imaginary (shared) past. The theoretical approach combines the concept of ‘policy implementation process’ (Bengtsson 2012) with ‘structuration theory’ (Giddens 1993). Focus is on the circulation of ideas and on what is ‘happening on the way’ as actors interact with policy and structures of stabilized actions. The research uses a combination of three examining studies and three case studies. In these studies, heritage management and participation are explored from an intertwined perspective, travelling through the processes of regulation, policymaking, implementation and effects through a direct interaction between public and civil actors. The case studies chosen all have the character of an ‘arranged dialogue process’ that aims towards integrating public and civil actors in heritage practice. The main source material consists of policy documents, project materials and oral statements. The dissertation identifies participation as a still unfixed, uncertain and contested concept. The implementation of participation as a political objective in heritage management (public administration and authority- making), therefore collides with a set of constraints. Consequently, participation continues to be more of a normative ideal for how to act, rather than an established new practice for heritage management. The discussion of results considers, firstly, that the arrangements needed to fulfil policy are depending on special efforts made by public actors to arrange a wider space for interaction and influence. Secondly, a renegotiated interpretation of participation is transiting the ideas of how, whom and what should be taken care of: heritage is used to overcome older asymmetries on who are being recognised and represented. The conclusion drawn, is that there is a need for acknowledging the enduring heterogeneity of the contemporary, by reinterpreting and a highlighting new parts of the past