Guidewire exchange vs new site placement for temporary dialysis catheter insertion in ICU patients: is there a greater risk of colonization or dysfunction?

Interventions for treating catheter-related bloodstream infections in people receiving maintenance haemodialysis

BACKGROUND

Patients with kidney failure require vascular access to receive maintenance haemodialysis (HD), which can be achieved by an arteriovenous fistula or a central venous catheter (CVC). CVC use is related to frequent complications such as venous stenosis and infection. Venous stenosis occurs mainly due to trauma caused by the entrance of the catheter into the venous lumen and repeated contact with the vein wall.  A biofilm, a colony of irreversible adherent and self-sufficient micro-organisms embedded in a self-produced matrix of exopolysaccharides, is associated with the development of infections in patients with indwelling catheters. Despite its clinical relevance, the treatment of catheter-related bloodstream infections (CRBSIs) in patients receiving maintenance HD remains controversial, especially regarding catheter management. Antibiotic lock solutions may sterilise the catheter, treat the infection and prevent unnecessary catheter procedures. However, such treatment may also lead to antibiotic resistance or even clinical worsening in certain more virulent pathogens. Catheter removal and delayed replacement may remove the source of infection, improving infectious outcomes, but this approach may also increase vascular access stenosis, thrombosis or both, or even central vein access failure. Catheter guidewire exchange attempts to remove the source of infection while maintaining access to the same vein and, therefore, may improve clinical outcomes and preserve central veins for future access.

OBJECTIVES

To assess the benefits and harms of different interventions for CRBSI treatment in patients receiving maintenance HD through a permanent CVC, such as systemic antibiotics alone or systemic antibiotics combined with either lock solutions or catheter guidewire exchange or catheter replacement.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 21 December 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs evaluating the management of CRBSI in permanent CVCs in people receiving maintenance HD.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed their risk of bias, and performed data extraction. Results were expressed as risk ratios (RR) or hazard ratios (HR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, with their 95% confidence intervals (CI). The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

We identified two RCTs and one quasi-RCT that enrolled 760 participants addressing the treatment of CRBSIs in people (children and adults) receiving maintenance HD through CVC. No two studies compared the same interventions. The quasi-RCT compared two different lock solutions (tissue plasminogen activator (TPA) and heparin) with concurrent systemic antibiotics. One RCT compared systemic antibiotics alone and in association with an ethanol lock solution, and the other compared systemic antibiotics with different catheter management strategies (guidewire exchange versus removal and replacement). The overall certainty of the evidence was downgraded due to the small number of participants, high risk of bias in many domains, especially randomisation, allocation, and other sources of bias, and missing outcome data. It is uncertain whether an ethanol lock solution used with concurrent systemic antibiotics improved CRBSI eradication compared to systemic antibiotics alone (RR 1.61, 95% CI 1.16 to 2.23) because the certainty of this evidence is very low. There were no reported differences between the effects of TPA and heparin lock solutions on cure rates (RR 0.92, 95% CI 0.74 to 1.15) or between catheter guidewire exchange versus catheter removal with delayed replacement, expressed as catheter infection-free survival (HR 0.88, 95% CI 0.43 to 1.79). To date, no results are available comparing other interventions. Outcomes such as venous stenosis and/or thrombosis, antibiotic resistance, death, and adverse events were not reported.

AUTHORS' CONCLUSIONS

Currently, there is no available high certainty evidence to support one treatment over another for CRBSIs. The benefit of using ethanol lock treatment in combination with systemic antibiotics compared to systemic antibiotics alone for CRBSIs in patients receiving maintenance HD remains uncertain due to the very low certainty of the evidence. Hence, further RCTs to identify the benefits and harms of CRBSI treatment options are needed. Future studies should unify CRBSI and cure definitions and improve methodological design.

Vascular access, membranes and circuit for CRRT

The advances in the technology for providing continuous renal replacement therapy (CRRT) have led to an increase in its utilization throughout the world. However, circuit life continues to be a major problem. It leads not only to decreased delivery of dialysis but also causes blood loss, waste of disposables, alters dose delivery of medications and nutrition, and increases nurse workload, all of which increases healthcare cost. Premature circuit failure can be caused by numerous factors that can be difficult to dissect out. The first component is the vascular access; without a well-placed, functioning access, delivery of CRRT becomes very difficult. This is usually accomplished by placing a short-term dialysis catheter into either the right internal jugular or femoral vein. The tips should be located at the caval atrial junction or inferior vena cava. In addition to establishing suitable vascular access, a comprehensive understanding of the circuit facilitates the development of a methodical approach in providing efficient CRRT characterized by optimal circuit life. Moreover, it aids in determining the cause of circuit failure in patients experiencing recurrent episodes. This review therefore summarizes the essential points that guide providers in establishing optimal vascular access. We then provide an overview of the main components of the CRRT circuit including the blood and fluid pumps, the hemofilter, and pressure sensors, which will assist in identifying the key mechanisms contributing to premature failure of the CRRT circuit.

Common errors in temporary hemodialysis catheter insertion

Non-tunneled hemodialysis catheter (NTHC) insertion is an essential skill for nephrology practice and remains a requirement of training. However, improper insertion technique can increase the risk of potentially fatal infectious and mechanical complications. Evidence-based strategies can reduce the rates of such complications and should be integrated into practice and training. Ultrasound (US) guidance should routinely be used for NTHC insertion at the femoral and internal jugular sites (with avoidance of the subclavian site). Nephrologists should receive proper training in the use of US for line insertion. With respect to other aspects of the procedure, proper insertion technique readily prevents guidewire-induced arrhythmias. In addition, adherence to infection-control guidelines results in a sustainable reduction in bloodstream infections. All these aspects of NTHC insertion may be best taught and evaluated through a program that includes simulation-based mastery learning (SBML) training. As a separate issue, nephrologists (and intensivists) should be aware that a dysfunctional catheter should be replaced at a new site rather than being changed over a guidewire. This review of common errors related to NTHC insertion seeks to highlight evidence-based approaches to practice and training.

A state of the art review on optimal practices to prevent, recognize, and manage complications associated with intravascular devices in the critically ill

Intravascular catheters are inserted into almost all critically ill patients. This review provides up-to-date insight into available knowledge on epidemiology and diagnosis of complications of central vein and arterial catheters in ICU. It discusses the optimal therapy of catheter-related infections and thrombosis. Prevention of complications is a multidisciplinary task that combines both improvement of the process of care and introduction of new technologies. We emphasize the main component of the prevention strategies that should be used in critical care and propose areas of future investigation in this field.

Haemodialysis catheters in the intensive care unit

Ten to 15% of critically ill patients need renal replacement therapy (RRT) for severe acute kidney injury. The dialysis catheter is critical for RRT quality and efficiency. Catheters have several properties that must be optimized to promote RRT success. The distal tip has to be located in a high blood flow location, which means central venous territory. Therefore, catheters are mostly inserted into the right internal jugular vein or in femoral veins. External diameter should vary from 12 to 16 Fr in order to ensure adequate blood flow inside the catheter. Lumen shapes are theoretically designed to limit thrombotic risk with low turbulences and frictional forces against the internal wall. With low aspiration pressure, distal tip shape has to deliver sufficient blood flow, while limiting recirculation rate. Catheter material should be biocompatible. Despite in vitro data, no strong evidence supports the use of coated catheters in the ICU in order to reduce infectious risk. Antibiotic "lock" solutions are not routinely recommended. Ultrasound guidance for catheterization significantly decreases mechanical complications. Clinicians should select the optimal catheter according to patient body habitus, catheter intrinsic properties and RRT modality to be used.