UNRESOLVED ISSUES IN DIALYSIS: Long-Term Management of the Tunneled Venous Catheter

Strategies to Prevent Hemodialysis Catheter Dysfunction

Millions of patients with kidney failure rely on hemodialysis central venous catheters (CVCs) for their life-sustaining dialysis treatments. CVC dysfunction necessitates removal of up to 20% of CVCs and is an important problem for patients with kidney failure. Thrombosis and fibrin sheath formation are the most common mechanisms of CVC dysfunction beyond the first week after insertion. Factors such as female sex, left-sided CVC placement, and prior CVC dysfunction are associated with a higher risk of dysfunction. Patient-specific factors contribute substantially to variation in the number of CVC dysfunction events. Weekly thrombolytic locks have been shown to improve CVC blood flow rates, prevent infection, and reduce dysfunction requiring removal. However, routine administration may not be cost-effective in hemodialysis units with low infection rates, and targeted use among patients with established CVC dysfunction has not been studied. Concentrated heparin lock ( e.g ., 5000 versus 1000 international unit/ml) has been associated with lower requirements for therapeutic CVC thrombolysis but greater systemic bleeding risks and costs. Citrate 4% was noninferior to standard heparin locks to prevent thrombosis, may cause less bleeding, and is less costly in some countries. Tunneled CVCs with a symmetrical tip have been associated with a lower risk of CVC dysfunction compared with those with a step tip. Multifaceted CVC care interventions can reduce the incidence of dysfunctional CVCs by 33% compared with usual care. Future research to identify patients at high risk of CVC dysfunction will inform individualized vascular access plans, targeted use of preventive strategies, and enrollment criteria for future clinical trials.

Differences in Efficacy between Antibacterial Lock Therapy and the Standard of Care for CVC-Related Infections: A Systematic Review and Meta-Analysis

Background: Central Venous Catheter (CVC)-related infections cannot always be solved by replacement, due to some vascular anomalies or an emergency status. This comprehensive, evidence-based review aimed to define the efficacy of antibacterial lock therapy (ALT) compared to the standard of care (SoC) in CVC-related infections. Methods: We performed a systematic search in PubMed, Embase, and Google Scholar, looking for randomized controlled trials (RCTs) and cohort or case-control observational studies. The eligible studies considered the subjects with a diagnosis of CVC-related infections treated with antibacterial lock therapy (ALT) compared to the standard of care (SoC). Results: Among 609 records at the end of the selection process, five articles, referring to observational studies, were included in this systematic review. In pooled analyses, including a total of 276 individuals, microbiological healing (OR 3.78; 95% CI; 2.03-7.03) showed significant differences between ALT and the SoC, with a follow-up varying from 2 weeks to 3 months. Conclusions: Our results suggested that ALT could improve the preservation of CVCs and could be considered when their replacement is not possible as a result of vascular problems. However, only observational studies were included and RCTs are needed to confirm these findings and to increase the level of evidence.

Brachiocephalic and Radiocephalic Arteriovenous Fistulas in Patients with Tunneled Dialysis Catheters Have Similar Outcomes

BACKGROUND

Patients with tunneled dialysis catheters (TDCs) have a time-sensitive need for a functional permanent access due to high risk of catheter-associated morbidity. Brachiocephalic arteriovenous fistulas (BCF) have been reported to have higher maturation and patency compared to radiocephalic arteriovenous fistulas (RCF), although more distal creation is encouraged when possible. However, this may lead to a delay in establishing permanent vascular access and, ultimately, TDC removal. Our goal was to assess short-term outcomes after BCF and RCF creation for patients with concurrent TDCs to see if these patients would potentially benefit more from an initial brachiocephalic access to minimize TDC dependence.

METHODS

The Vascular Quality Initiative hemodialysis registry was analyzed from 2011 to 2018. Patient demographics, comorbidities, access type, and short-term outcomes including occlusion, reinterventions, and access being used for dialysis, were assessed.

RESULTS

There were 2,359 patients with TDC, of whom 1,389 (58.9%) underwent BCF creation and 970 (41.1%) underwent RCF creation. Average patient age was 59 years, and 62.8% were male. Compared with RCF, those with BCF were more often older, of female sex, obese, nonindependently ambulatory, have commercial insurance, diabetes, coronary artery disease, chronic obstructive pulmonary disease, be on anticoagulation, and have a cephalic vein diameter of ≥3 mm (all P < 0.05). Kaplan-Meier analysis for 1-year outcomes for BCF and RCF, respectively, showed that primary patency was 45% vs. 41.3% (P = 0.88), primary assisted patency was 86.7% vs. 86.9% (P = 0.64), freedom from reintervention was 51.1% vs. 46.3% (P = 0.44), and survival was 81.3% vs. 84.9% (P = 0.02). Multivariable analysis showed that BCF was comparable to RCF with respect to primary patency loss (hazard ratio [HR] 1.11, 95% confidence interval [CI] 0.91-1.36, P = 0.316), primary assisted patency loss (HR 1.11, 95% CI 0.72-1.29, P = 0.66), and reintervention (HR 1.01, 95% CI 0.81-1.27, P = 0.92). Access being used at 3 months was similar but trending towards RCF being used more often (odds ratio 0.7, 95% CI 0.49-1, P = 0.05).

CONCLUSIONS

BCFs do not have superior fistula maturation and patency compared to RCFs in patients with concurrent TDCs. Creation of radial access, when possible, does not prolong TDC dependence.

Strategies to Prevent Infections in Dialysis Patients

Infections are the second leading cause of death among patients with end-stage kidney disease, behind only cardiovascular disease. In addition, patients on chronic dialysis are at a higher risk for acquiring infection caused by multidrug-resistant organisms and for death resulting from infection owing to their likelihood of requiring treatment that involves invasive devices, their frequent exposure to antibiotics, and their impaired immunity. Vascular access is a major risk factor for bacteremia, hospitalization, and mortality among hemodialysis (HD) patients. Catheter-related bacteremia is the most severe central venous catheter (CVC)-related infection and increases linearly with the duration of catheter use. Given the high prevalence of CVC use and its direct association with catheter-related bacteremia, which adversely impacts morbidity and mortality rates among HD patients, several prevention measures aimed at reducing the rates of CVC-related infection have been proposed and implemented. As a result, a large number of clinical trials, systematic reviews, and meta-analyses have been conducted to assess the effectiveness, clinical applicability, and long-term adverse effects of such measures. Peritoneal dialysis chronic treatment without the occurence of peritonitis is rare. Although most cases of peritonitis can be treated adequately with antibiotics, some cases are complicated by hospitalization or a temporary or permanent need to abstain from using the peritoneal dialysis catheter. Severe and long-lasting peritonitis can lead to peritoneal membrane failure, requiring the treatment method to be switched to HD. Some measures as patients training, early diagnosis, and choice of antibiotics can contribute to the successful treatment of peritonitis. Finally, medical directors are key leaders in infection prevention and are an important resource to implement programs to monitor and improve infection prevention practices at all levels within the dialysis clinic.

Incidence and challenges in management of hemodialysis catheter-related infections

Catheter-related infections (CRI) are a major cause of morbidity and mortality in chronic hemodialysis (HD) patients. In this paper, we share our experience with CRI in HD patients. We recorded 49 cases of CRI among 167 patients during a period of 40 months (January 2018-April 2021). The incidence of CRI was 3.7 per 1000 catheter-days. The revealing symptoms were dominated by fever or chills (90%). Inflammatory signs were observed in 74% of cases with respectively concurrent exit-site (51%) and tunnel infection (6%). The biological inflammatory syndrome was found in 74% of patients (average CRP level = 198.9 mg/l). Blood cultures were performed in all cases and were positive in 65% of cases. Thirteen patients have been diagnosed with Infection complications, which were respectively infective endocarditis in 7 cases, septic arthritis in 3 cases, infective myositis in one case, cerebral thrombophlebitis in 1 case and mediastinitis in 1 case. The death occurred in eleven patients, it was due to septic shock in 9 cases, pulmonary embolism in one case and neurologic alterations related to cerebral thrombophlebitis. The mean seniority in HD was 16.5 months in the group with CRI and 3.7 months in the group without CRI (p < 0.04). We did not notice significant difference in mortality between tunnelled and non-tunnelled catheters. CRI does not seem to be more severe in patients with diabetes. Duration of use of the HD catheter (p < 0.007) and ferritin level (p < 0.0001) were independent factors that predispose to CRI in our population.

Pathology of catheter-related complications: what we need to know and what should be discovered

Despite the considerable efforts made to increase the prevalence of autogenous fistula in patients on hemodialysis, tunneled cuffed catheters are still an important access modality and used in a high percentage of the hemodialysis population. However, because of the conundrum posed by tunneled cuffed catheters, patients can develop a multitude of complications, including thrombosis, infections, formation of a fibrin sheath, and central vein stenosis, resulting in increased morbidity and mortality as well as placing a heavy burden on the healthcare system. However, with an increasing number of studies now focusing on how to manage these catheter-related complications, there has been less translational research on the pathology of these complications. This review of the most recent literature provides an update on the pathological aspects of catheter-related complications, highlighting what we need to know and what is yet to be discovered. The future research strategies and innovations needed to prevent these complications are also addressed.

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.

Endovascular treatment of the stuck hemodialysis catheter: A report of two cases and literature review

A considerable number of patients present with stuck CVC after long-use of CVC, which is thought to result from the adhesion of the fibrous sheath, formed over the CVC, to the vessel or atrial wall. The removal of these catheters is a difficult and risky procedure. Hong reported a minimally invasive technique through endoluminal balloon dilation, which successfully breaks the adhesions and expands the vein, thus allowing for an easy removal of the CVC. The authors present two cases of a variant method of Hong's technique, and provide a literature review on stuck catheters. Our experience is that balloon angioplasty dilation is a safe and practical option. We highlight the role of experienced interventional nephrologists or radiologists in the management of this complication as endovascular treatment is the first line treatment.

Central Venous Catheters for Hemodialysis-the Myth and the Evidence

Hemodialysis-central venous catheter (HD-CVC) insertion is a most often performed procedure, with approximately 80% of patients with end-stage kidney disease in the United States initiating kidney replacement therapy through a HD-CVC. Certain adverse events arising from HD-CVC placement, including catheter-related bloodstream infections (CR-BSIs), thrombosis, and central vein stenosis, can complicate the clinical course of patients and lead to considerable financial impact on the health care system. Medical professionals with different training backgrounds are responsible for performing this procedure, and therefore, comprehensive operator guidelines are crucial to improve the success rate of HD-CVC insertion and prevent complications. In this review article, we not only discuss the basic principles behind the use of HD-CVCs but also address frequently asked questions and myths regarding catheter asepsis, length selection, tip positioning, and flow rate assessment.

A Randomized Controlled Trial of Comparative Efficacy between Sodium Bicarbonate and Heparin as A Locking Solution for Tunneled Central Venous Catheters Among Patients Requiring Maintenance Hemodialysis

Background:

Sodium bicarbonate (NaHCO₃) is one of the promising solutions that has good safety profile and theoretical advantages regarding antimicrobial and antithrombotic properties but there are still limited reports.

Objective:

To compare the efficacy in lowering rate of catheter loss due to catheter-related thrombosis (CRT) or catheter-related blood stream infection (CRBSI) between sodium bicarbonate and heparin lock in prevalent chronic hemodialysis (HD) patients.

Design:

A multicenter, randomized, open-label study

Setting:

In a developing country, Thailand

Patients:

Chronic HD patients with tunneled central venous catheter

Measurements:

Catheter loss rate, rate of catheter-related blood stream infection, catheter-related thrombosis, and exit site or tunnel infection

Methods:

The prospective multicenter randomized controlled trial was conducted, we randomly assigned 118 patients undergoing HD with tunneled central venous catheter to receive a catheter locking solution of sodium bicarbonate or heparin. The primary outcome was a catheter loss rate due to CRT or CRBSI, while the secondary outcome was a composite outcome of CRT, CRBSI, or exit site/tunnel infection (ESI/TI).

Results:

The present study was stopped early due to an excess of catheter-related thrombosis in the sodium bicarbonate group. From the first 6 weeks of follow-up, there were no catheter losses due to CRT or CRBSI in both groups. The sodium bicarbonate group had a significantly higher rate of the secondary composite outcomes and this was entirely caused by CRT with the median time to thrombosis of 23.6 days. Every CRT event could be successfully rescued by using a single dose of recombinant tissue plasminogen activator (rt-PA).

Limitations:

Short follow-up period.

Conclusions:

In prevalent HD patients with tunneled CVCs, use of a sodium bicarbonate locking solution for prevention of CRT is inferior to heparin and is associated with a high rate of catheter-related thrombosis.

Trial registration:

The study was registered with the Thai Clinical Trials Registry TCTR 20200610003

Fibrin sheath disruption during guidewire exchange for bacteremia: Low recurrence of infection and preservation of vascular access sites

BACKGROUND

Catheter-associated bacteremia (CAB) often leads to removal of tunneled dialysis catheters with delayed insertion (RDI). Exchange over a guidewire (ExW) can be considered for access site preservation. Fibrin sheath disruption (FSD) during exchange is not standard practice for infected catheters. Here we present the first analysis of outcomes after such exchanges (ExW-FSD).

METHODS

Retrospective analysis of catheter exchanges and removals performed by interventional nephrology for bacteremia in 2008-2011 observed for 20.5 months. Charts were reviewed for recurrent or new bacteremia and death at 3 months, and for occurrence of thrombosis or stenosis along the catheter site. Catheter exchange with central venogram and fibrin sheath disruption was our standard of care in all patients presenting for CAB. RDI was performed either for tunnel infection, non-clearing of infection or at the request of referring physicians.

RESULTS

Over 4 years, 66 patients were treated for CAB. Forty-two patients underwent ExW-FSD, which was performed even for Staph. aureus, gram negative bacteremia or candidemia. RDI was performed in 24 cases. Bacteremia recurred in 3 (7%) patients after ExW-FSD, and in 7 (30%) cases after RDI (p = 0.02). There was no significant difference in new infections: 5 (12%) after ExW-FSD and 2 (8%) after RDI. There was no death within 3 months after ExW-FSD and 4 (27%) (p = 0.005) deaths in the RDI group.There was one new central venous stenosis in the ExW-FSD group (2%) with no loss of access site, and 8 (33%) patients developed thrombosis/stenosis along the prior catheter track after RDI (33%) (p = 0.006) with loss of access site in (21%).

CONCLUSIONS

In this retrospective analysis of treatment of CAB, ExW-FSD was associated with lower recurrence of bacteremia, lower death rate and a lower incidence of access site loss compared to RDI. These data support ExW-FSD use in patients with CAB.

Outcomes of tunneled cuffed hemodialysis catheters: An experience from a tertiary care center in Karachi, Pakistan

INTRODUCTION

Tunneled cuffed catheters (TCC) are generally used as a temporary means to provide hemodialysis (HD) until permanent arteriovenous access is established. However, certain complications are associated with use of TCCs such as infections, catheter malfunction/malposition or venous stenosis. Limited data is available on outcomes and long term complications associated with TCCs in our country. The aim of this study was to study the outcomes of TCCs and associated long term complications during the course of its usage.

METHODS

We retrospectively studied case records of patients who had TCCs placed for HD at our institution, from January 2016 to June 2018.

RESULTS

A total of 116 TCCs were placed during the study period. The mean age of the population was 57.09 years; 58.6% were males. The right internal jugular vein (52.6%) was the most common site of TCC insertion followed by the left internal jugular vein (29.3%). Functioning TCCs were successfully removed in almost two-thirds of cases (65.7%) once their permanent access was mature. Development of catheter related blood stream infection (CRBSI) was seen in 22 patients (19.8%) requiring catheter removal in 14 (12.6%) patients. Mechanical complications leading to catheter removal were seen in seven patients (6.3%). The median catheter duration was 62.5 days ranging from 1 to 343 days.

CONCLUSION

TCCs, though associated with complications particularly CRBSI, are a viable option for short- to intermediate-term use for HD till the maturation of permanent arteriovenous access in a limited-resource setting.

Reasons for long-term tunneled dialysis catheter use and associated morbidity

OBJECTIVE

Tunneled dialysis catheters (TDCs) are generally used as a temporary means to provide hemodialysis until permanent arteriovenous (AV) access is established. However, some patients may have long-term catheter-based hemodialysis because of the lack of alternatives for other dialysis access. Our objective was to evaluate characteristics of patients with, reasons for, and mortality associated with long-term TDC use.

METHODS

A retrospective single-institution analysis was performed. Long-term TDC use was defined as >180 days without more than a 7-day temporary removal time. Reasons for long-term TDC use and complications were recorded. Summary statistics were performed. Kaplan-Meier analysis compared mortality between patients with long-term TDC use and a comparison cohort who underwent AV access creation with subsequent TDC removal.

RESULTS

We identified 50 patients with long-term TDC use from 2013 to 2018. The average age was 63 years, 44% were male, and 76% were African American. Previous TDC use was found in 42% of patients with subsequent removal after alternative access was established. Median TDC duration was 333 days (range, 185-2029 days). The primary reasons for long-term TDC use were failed (occluded) AV access (34%), nonmaturing AV (nonoccluded) access (32%), delayed AV access placement (14%), no AV access options (10%), patient refusal for AV access placement (6%), and medically high risk for AV access placement (4%). In 46% of patients, TDC complications including central venous stenosis (33.4%), TDC-related infections (29.6%), TDC displacement (27.8%), and thrombosis (7.9%) occurred. Overall, 47.6% required a catheter exchange during the prolonged TDC period. The majority (76.4%) had the catheter removed because of established alternative access during follow-up. The long-term TDC group, in relation to the comparator group (n = 201), had fewer male patients (44% vs 61.2%; P = .028) and higher proportion of congestive heart failure (66% vs 40.3%; P = .001). Kaplan-Meier analysis showed no significant difference in survival at 24 months for the long-term TDC group compared with the comparator group (93.6% vs 92.7%; P = .28).

CONCLUSIONS

Patients with long-term TDCs experienced significant TDC-related morbidity. Whereas permanent access is preferable, some patients may require long-term TDC use because of difficulty in establishing a permanent access, limited access options, and patient preference. There was no difference in survival between the groups.

Catheter-related obstruction of the right brachiocephalic vein following hemodialysis in a patient with lupus nephritis

Vascular access is necessary for hemodialysis, and in some cases where it is difficult to establish an arteriovenous fistula or arteriovenous graft, a permanent hemodialysis catheter may be used. However, serious catheter-related complications, such as central vein stenosis or thrombosis, can occur. We herein present a case of complete brachiocephalic vein obstruction in a patient with lupus nephritis receiving hemodialysis using a tunneled hemodialysis catheter. A 64-year-old patient underwent maintenance hemodialysis while taking an anticoagulant, with a tunneled hemodialysis catheter in the right internal jugular vein, because of arteriovenous fistula failure when hemodialysis was introduced. However, the catheter was removed because of a catheter-related bloodstream infection. Following the administration of antibiotics, an arteriovenous graft was implanted between the brachial artery and axillary vein in the right arm. Surprisingly, arteriovenous graft failure and complete obstruction of the right brachiocephalic vein were observed 3 days after arteriovenous graft creation. In conclusion, we report the case of tunneled hemodialysis catheter-related complete obstruction of the right brachiocephalic vein in a lupus nephritis patient undergoing hemodialysis. Clinicians should be aware of this potential complication when tunneled hemodialysis catheters are used and consider the next vascular access type before a tunneled hemodialysis catheter has been indwelled for the long term.

Midterm outcomes of brachial arterio-arterial prosthetic loop as permanent hemodialysis access

OBJECTIVE

The objective of this study was to report the midterm outcomes of the brachial arterio-arterial prosthetic loop (AAPL) as an alternative permanent vascular access in strictly selected patients with end-stage renal disease.

METHODS

This single-center prospective observational study was conducted between January 2014 and June 2017 and included 89 brachial AAPL procedures. Primary, assisted primary, and secondary patency rates were calculated using Kaplan-Meier analysis.

RESULTS

Exhausted peripheral veins were the most common indication for brachial AAPL. Patients were followed up for a mean period of 28.7 ± 4.9 months. Nineteen grafts developed thrombosis, 13 grafts developed pseudoaneurysms, 9 grafts developed hematoma, and 6 grafts were abandoned because of infection. The primary, assisted primary, and secondary patency rates were 62% ± 5.2%, 71.2% ± 4.9%, and 89.6% ± 3.3% at 24 months, respectively.

CONCLUSIONS

Brachial AAPL can offer a simple, safe, and efficient alternative as a permanent hemodialysis access in a selected subset of end-stage renal disease patients, with acceptable durability and rate of complications. Because of its unique specifications, cooperation between vascular surgeons and dialysis staff is mandatory.

Heparin flush vs. normal saline flush to maintain the patency of central venous catheter among adult patients: A systematic review and meta-analysis

BACKGROUND

Around the globe, protocols for flushing the catheter to maintain the patency of central venous catheter (CVC) vary by institution to institution or by practitioner to practitioner. Therefore, this review was carried out with the aim of evaluating the efficacy of heparin flush vs. normal saline flush to maintain the patency of CVC among adult patients.

METHODS

We followed the guidelines of Cochrane handbook for interventions and searched in MEDLINE, Embase, Cochrane library, Clinical trials database, and reference list of related articles, which were published from Jan. 2012 to 31 Dec. 2018 in English language. We included only randomized controlled trials, and nine studies were included in this review. The pooled standard mean difference and relative risk were calculated by using Rev Man Review Manager 5.

RESULTS

We identified nine eligible studies with a total number of 3,113 participants. Consolidated results from eight studies conveyed little favorable effect to maintain patency of CVC with heparin when compared with normal saline as evident by risk ratio 0.83, 95% CI 0.50 - 1.40; P = 0.13. We also carried out analysis for secondary outcomes, and there was no evidence that heparin was better than normal saline in terms of safety except heparin-induced thrombocytopenia.

CONCLUSIONS

Heparin has little favorable effects to maintain patency of catheter than normal saline but not in secondary outcomes. As the quality of evidence was very low, therefore, results should be comprehend with care.

Confusing radiographic appearance of a central venous split-tip hemodialysis catheter

Long-term cuffed hemodialysis catheters are being increasingly used in the management of patients with chronic kidney disease. These tunneled catheters are available in different types and characteristics. Patients undergo imaging, primarily chest radiographs to confirm the position of the catheter tip. It is essential to be aware of the normal imaging appearances of these catheters as they may simulate pathological appearance due to the shape of their tips. This knowledge will help avoid misdiagnosis and unnecessary medical interventions.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

A Review of Arteriovenous Fistulae Creation in Octogenarians

BACKGROUND

To analyze the outcomes of arteriovenous fistulae (AVFs) creation in octogenarians.

METHODS

A retrospective study of 47 AVFs created in patients aged 80 years and above from 2008 to 2014. Patient and AVF characteristics and outcomes were evaluated. Predictors of patency were analyzed with multivariate analysis and Kaplan-Meier patency, and survival analysis was performed.

RESULTS

Forty-seven of 1,259 AVFs created were for octogenarians (4%). Mean age was 83 years old (range: 80-91 years), with 27 male (57%) and 35 with tunneled dialysis catheters in situ (75%). There were a total of 15 (32%) radiocephalic AVFs, 30 (64%) brachial-cephalic AVFs, and 2 (4%) brachial-basilic transposition AVFs. At 12 months, assisted primary patency rate was 28% (13 patients) while primary failure rate was 72% (34 patients). Subset analysis showed brachial-cephalic AVFs to have the highest assisted primary patency rate at 33%. Within 24 months, tunneled dialysis catheter-related sepsis rate was 31% (11 patients). Multivariate analysis did not reveal any factor to be statistically significant in predicting AVF patency. Kaplan-Meier survival curve showed a 50% survival rate at 63 months after AVF creation.

CONCLUSIONS

In view of high AVF primary failure rate and relatively low tunneled dialysis catheter bacteremia rate, long-term tunneled dialysis catheters as the main form of hemodialysis renal access may be a viable option. However, with 50% of end-stage renal failure patients surviving up to 63 months after AVF creation, the risks and benefits of long-term tunneled dialysis catheters must be balanced against those of AVF creation.

Urgent-Start Peritoneal Dialysis and Hemodialysis in ESRD Patients: Complications and Outcomes

BACKGROUND

Several studies have suggested that urgent-start peritoneal dialysis (PD) is a feasible alternative to hemodialysis (HD) in patients with end-stage renal disease (ESRD), but the impact of the dialysis modality on outcome, especially on short-term complications, in urgent-start dialysis has not been directly evaluated. The aim of the current study was to compare the complications and outcomes of PD and HD in urgent-start dialysis ESRD patients.

METHODS

In this retrospective study, ESRD patients who initiated dialysis urgently without a pre-established functional vascular access or PD catheter at a single center from January 2013 to December 2014 were included. Patients were grouped according to their dialysis modality (PD and HD). Each patient was followed for at least 30 days after catheter insertion (until January 2016). Dialysis-related complications and patient survival were compared between the two groups.

RESULTS

Our study enrolled 178 patients (56.2% male), of whom 96 and 82 patients were in the PD and HD groups, respectively. Compared with HD patients, PD patients had more cardiovascular disease, less heart failure, higher levels of serum potassium, hemoglobin, serum albumin, serum pre-albumin, and lower levels of brain natriuretic peptide. There were no significant differences in gender, age, use of steroids, early referral to a nephrologist, prevalence of primary renal diseases, prevalence of co-morbidities, and other laboratory characteristics between the groups. The incidence of dialysis-related complications during the first 30 days was significantly higher in HD than PD patients. HD patients had a significantly higher probability of bacteremia compared to PD patients. HD was an independent predictor of short-term (30-day) dialysis-related complications. There was no significant difference between PD and HD patients with respect to patient survival rate.

CONCLUSION

In an experienced center, PD is a safe and feasible dialysis alternative to HD for ESRD patients with an urgent need for dialysis.

Duplex Ultrasound for the Prediction of Vascular Events Associated with Arteriovenous Fistulas in Hemodialysis Patients

Objective

To determine if duplex ultrasound (US) for arteriovenous fistulas (AVFs) can predict vascular events (VEs; thrombosis and stenosis).

Methods

Duplex US was performed for vascular access evaluation in 2557 maintenance hemodialysis (HD) patients between October 1, 2013 and March 31, 2016. Of these patients, 2184 patients were finally included in this study. AVF dysfunction was assessed using the brachial artery blood flow volume (Qa; mL/min), arterial blood flow resistance index (RI), and residual diameter of the fistula vein (RD; mm). Proximal, midpoint, and distal aspects of the fistulas were measured. The baseline measurements were the US assessments, and the endpoint was VEs requiring vascular access intervention therapy or vascular surgery. Associations of US findings and VEs were assessed with receiver operating characteristic curve analysis, log-rank analysis, and multivariate Cox hazard models.

Results

The mean Qa was 772.8 ± 441.4 mL/min; RI, 0.56 ± 0.1; and RD, 2.37 ± 1.0 mm. The optimal Qa cut-off point was calculated as 581.5 mL/min, RI cut-off as 0.56, and RD cut-off as 1.85 mm. VEs were more frequent in patients with a Qa <581.5 mL/min than in those with a Qa >581.5 mL/min (p<0.001). In multivariate analysis, Qa, ferritin, transferrin saturation, and warfarin use were significantly associated with VEs.

Conclusions

US evaluation of AVFs in HD patients is a simple method to predict the risks of thrombosis and fistula dysfunction. Qa, ferritin, transferrin saturation, and warfarin use might be associated with VEs.

Anticoagulants and antiplatelet agents for preventing central venous haemodialysis catheter malfunction in patients with end-stage kidney disease

BACKGROUND

Catheter malfunction, including thrombosis, is associated with reduced dialysis adequacy, as well as an increased risk of catheter-related bacteraemia and mortality. The role of anticoagulants in the prevention of catheter malfunction remains uncertain.

OBJECTIVES

This review aimed to compare the prophylactic effect of different anticoagulant agents, preparations, doses and administration on the incidence of central venous haemodialysis catheter-related malfunction and sepsis in patients with end-stage kidney disease (ESKD).

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 7 January 2016 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included all randomised controlled trials (RCT) assessing anticoagulants compared with conventional care for the prevention of catheter malfunction in adult patients receiving haemodialysis for ESKD.

DATA COLLECTION AND ANALYSIS

The primary outcome was catheter malfunction defined as a catheter blood flow of 200 mL/min or less, or as defined by study authors. Secondary outcomes were catheter-related bacteraemia, all-cause mortality and bleeding events. Relative risks (RR) with 95% confidence intervals (CI) for individual studies were pooled using random effects models within treatment classes. Analyses were conducted by class, with subgroup analyses performed of individual agents within classes.

MAIN RESULTS

We included 27 studies (3003 participants) that were followed up for a median of six months. Study interventions included alternative anticoagulant locking solutions (19 studies, 2216 patients), systemic agents (6 studies, 664 patients) and low or no dose heparin (2 studies, 123 patients). The most common comparison treatment was a locking solution of heparin 5000 IU/mL, used in 17 studies. No significant effect on catheter malfunction was observed for alternative anticoagulant locking solutions (RR 0.96, 95% CI 0.74 to 1.26), systemic agents (RR 0.59, 95% CI 0.28 to 1.23), or low or no dose heparin (RR 0.90, 95% CI 0.10 to 8.31). A significant reduction on incidence of catheter-related bacteraemia was observed for alternative anticoagulant locking solutions (RR 0.46, 95% CI 0.32 to 0.66) but not systemic agents (RR 2.41, 95% CI 0.89 to 6.55), and could not be assessed in reports of low or no dose heparin studies. No significant effect on all-cause mortality was observed for alternative anticoagulant locking solutions (RR 0.88, 95% CI 0.54 to 1.43) or systemic agents (RR 0.78, 95% CI 0.37 to 1.65), and was not reported in studies of low or no dose heparin. Bleeding events were only reported in eight studies, including only 2/5 studies of systemic warfarin, with no clear effect demonstrated (RR 1.43, 95% CI 0.86 to 2.39). For individual agents, recombinant tissue plasminogen (rt-PA) was the only locking solution shown to reduce catheter malfunction (RR 0.58, 95% CI 0.37 to 0.91) based on the results of a single study. No significant on catheter malfunction was observed for other individual classes of alternative anticoagulant locking solutions (citrate: RR 1.14, 95% CI 0.76 to 1.69; antibiotic: RR 1.48, 95% CI 0.79 to 2.77; ethanol: RR 0.88, 95% CI 0.21 to 3.67). On the other hand, all individual classes of alternative anticoagulant locking solutions, except ethanol, reduced catheter-related bacteraemia (citrate: RR 0.49, 95% CI 0.36 to 0.68; antibiotic: RR 0.27, 95% CI 0.11 to 0.70; rt-PA: RR 0.35, 95% CI 0.13 to 0.93; ethanol: RR 0.33, 95% CI 0.03 to 4.05). No significant effect on all-cause mortality was observed for any individual agent within the class of alternative locking solutions. Studies were mainly of low quality and underpowered with an average participant number of 75 and study duration of six months. The interpretation of the study evidence was further limited by the variation in tested interventions and outcome reporting.

AUTHORS' CONCLUSIONS

The relative net benefit of anticoagulant therapies for prevention of catheter malfunction remains uncertain. Multiple agents appear to reduce catheter-related bacteraemia although the lack of clear assessment of harms and the limitations of study quality mean these results should be interpreted with caution. Methodological approaches can be used to avoid methods of reporting unduly affecting on the results of meta-analyses incorporating studies employed mixed reporting methods. Further high quality randomised studies, including safety outcomes, are needed.

Safety and Complications of Double-Lumen Tunnelled Cuffed Central Venous Dialysis Catheters: Clinical and radiological perspective from a tertiary centre in Oman

OBJECTIVES

This study aimed to assess the technical success, safety and immediate and delayed complications of double-lumen tunnelled cuffed central venous catheters (TVCs) at the Sultan Qaboos University Hospital (SQUH), Muscat, Oman.

METHODS

This retrospective study took place between January 2012 and October 2013. The clinical records and radiological data of all patients who underwent ultrasound- and fluoroscopy-guided TVC placement at SQUH during the study period were reviewed. Demographic data and information regarding catheter placement, technical success and peri- and post-procedure complications (such as catheter-related infections or thrombosis) were collected.

RESULTS

A total of 204 TVCs were placed in 161 patients. Of these, 68 were female (42.2%) and 93 were male (57.8%). The mean age of the patients was 54.4 ± 17.3 years. The most common reason for catheter placement was the initiation of dialysis (63.4%). A total of 203 procedures were technically successful (99.5%). The right internal jugular vein was the most common site of catheter placement (74.9%). Mild haemorrhage which resolved spontaneously occurred in 11 cases (5.4%). No other complications were observed. Subsequent follow-up data was available for 132 catheters (65.0%); of these, thrombosis-related catheter malfunction was observed in 22 cases (16.7%) and catheter-related infection in 29 cases (22.0%).

CONCLUSION

Radiological-guided placement of tunnelled haemodialysis catheters can be performed safely with excellent technical success. The success rate of catheter insertion at SQUH was favourable in comparison with other studies reported in the literature.

Heparin compared with normal saline to maintain patency of permanent double lumen hemodialysis catheters: A randomized controlled trial

Background:

Heparin has long been used to prevent thrombosis in the permanent central venous hemodialysis catheters (PermCath). Other alternatives for heparin with fewer side-effects have recently been considered. We compared normal saline (0.9%) with heparin for flushing PermCath with regards to catheter patency and prevention of heparin complications.

Materials and Methods:

Chronic kidney disease patients who were candidate of PermCath placement were randomly assigned into two groups of heparin and saline. In the heparin group, the PermCath was flushed with heparin (1000 IU), and in the saline group, it was flushed with saline 0.9%. Patients were followed for 24 hours, and outcomes included catheter thrombosis, maneuver needed to maintain catheter patency, and bleeding from catheter site.

Results:

Ninety six patients were included (age = 63.1 ± 11.2 years, 54.2% male). No one experienced catheter thrombosis. Two patient (4.2%) in the heparin and three ones (6.1%) in the saline group required catheter manipulation (P = 0.520). Four patients (8.5%) in the heparin and three ones (6.1%) in the saline group experienced bleeding (P = 0.476); differences between heparin and saline groups in the amount of bleeding (225.0 ± 62.4 vs. 200.0 ± 113.5 cc, P = 0.721) and bleeding time (6.5 ± 1.2 vs. 5.3 ± 1.5 min, P = 0.322) were not significant. In the heparin group, no significant increase was observed in PTT over time; baseline 30.9 ± 3.4, 12 h 31.8 ± 3.4, 24 h 31.2 ± 6.6 (P = 0.628).

Conclusions:

Flushing PermCath with normal saline 0.9% is as effective as heparin in maintaining patency of the catheter, while it may reduce the risks associated with heparin.

Fibrin sheath angioplasty: a technique to prevent superior vena cava stenosis secondary to dialysis catheters

Fibrin sheaths are a heterogeneous matrix of cells and debris that form around catheters and are a known cause of central venous stenosis and catheter failure. A total of 50 cases of central venous catheter fibrin sheath angioplasty (FSA) after catheter removal or exchange are presented. A retrospective review of an outpatient office database identified 70 eligible patients over a 19-month period. After informed consent was obtained, the dialysis catheter exiting the skin was clamped, amputated, and a wire was inserted. The catheter was then removed and a 9-French sheath was inserted into the superior vena cava, a venogram was performed. If a fibrin sheath was present, angioplasty was performed using an 8 × 4 or 10 × 4 balloon along the entire length of the fibrin sheath. A completion venogram was performed to document obliteration of the sheath. During the study, 50 patients were diagnosed with a fibrin sheath, and 43 had no pre-existing central venous stenosis. After FSA, 39 of the 43 patient's (91%) central systems remained patent without the need for subsequent interventions; 3 patients (7%) developed subclavian stenoses requiring repeat angioplasty and stenting; 1 patent (2.3%) developed an occlusion requiring a reintervention. Seven patients with prior central stenosis required multiple angioplasties; five required stenting of their central lesions. Every patient had follow-up fistulograms to document long-term patency. We propose that FSA is a prudent and safe procedure that may help reduce the risk of central venous stenosis from fibrin sheaths due to central venous catheters.

Successful prevention of tunneled central catheter infection by antibiotic lock therapy using cefazolin and gentamicin

Catheter-related bacteremia (CRB) is one of the various complications related to hemodialysis (HD). As a result of this high rate of infection, the antibiotic lock technique (ALT) has been recommended to prevent CRB. However, adverse effects of ALT such as increased emergence of strains resistant to antibiotics and increased mechanical dysfunction catheter were poorly evaluated. We prospectively evaluated the efficacy of catheter-restricted filling using an antibiotic lock solution in preventing CRB. A total of 233 HD patients requiring 325 new tunneled catheters while waiting for placement and maturation of an arteriovenous fistula or graft were enrolled in this study. Patients with a tunneled catheter were assigned to receive either an antibiotic-heparin lock solution (antibiotic group: cefazolin 10 mg/ml, gentamicin 5 mg/ml, heparin 1,000 U/ml) or a heparin lock solution (no-antibiotic group: heparin 1,000 U/ml) as a catheter lock solution during the interdialytic period. The present study aimed to assess the efficacy of ALT using cefazolin and gentamicin in reducing CRB in patients undergoing HD with tunneled central catheter and to identify its adverse effects. CRB developed in 32.4 % of patients in the no-antibiotic group and in 13.1 % of patients in the antibiotic group. CRB rates per 1,000 catheter-days were 0.57 in the antibiotic group versus 1.74 in the no-antibiotic group (p < 0.0001). Kaplan-Meier analysis also showed that mean CRB-free catheter survival was significantly higher in the antibiotic group than in the no-antibiotic group (log-rank statistic 17.62, p < 0.0001). There was statistically significant difference between the two groups in causative organisms of CRB, with predominance of negative culture in both groups, but this prevalence was higher in ALT group (57.9 vs 90.1 %, p < 0.0001), and the two groups also were different in prevalence of gram-positive bacteria as causing organisms (ALT group 21.05 vs = 0 % in control group, p < 0.0001). There was no statistically significant difference between the two groups in drug-resistant germs. There were statistically significant differences between the two groups in the catheter removal causes, with higher rate of infectious cause in control group (12.32 vs 2.22 %, p < 0.0001) and mechanical cause in ALT group (28.26 vs 37.78 %, p < 0.0001). The results suggest that ALT may be a beneficial means of reducing the CRB rate in HD patients with tunneled catheter, without association between ALT and emergence of strains resistant. However, mechanical complications were more prevalent in antibiotic group. Further studies are required to determine the optimal drug regimen, concentrations for ALT, and its adverse effects.

Minimizing hemodialysis catheter dysfunction: an ounce of prevention

The maintenance of tunneled catheter (TC) patency is critical for the provision of adequate hemodialysis in patients who are TC-dependent. TC dysfunction results in the need for costly and inconvenient interventions, and reduced quality of life. Since the introduction of TCs in the late 1980s, heparin catheter lock has been the standard prophylactic regimen for the prevention of TC dysfunction. More recently, alternative catheter locking agents have emerged, and in some cases have shown to be superior to heparin lock with respect to improving TC patency and reducing TC-associated infections. These include citrate, tissue plasminogen activator, and a novel agent containing sodium citrate, methylene blue, methylparaben, and propylparaben. In addition, prophylaxis using oral anticoagulants/antiplatelet agents, including warfarin, aspirin, ticlodipine, as well as the use of modified heparin-coated catheters have also been studied for the prevention of TC dysfunction with variable results. The use of oral anticoagulants and/or antiplatelet agents as primary or secondary prevention of TC dysfunction must be weighed against their potential adverse effects, and should be individualized for each patient.

The catheter-challenged patient and the need to recognize the recurrently dysfunctional tunneled dialysis catheter

Tunneled dialysis catheters (TDC) become dysfunctional because of placement problems, infection, thrombosis, and fibrin sheath formation. Occasional patients who are catheter dependant develop frequent catheter dysfunction because of thrombosis or thrombosis associated with fibrin sheath formation. This article attempts to define which dysfunctional catheters because of thrombosis and thrombosis associated with fibrin sheath formation actually represent a recurrently dysfunctional TDC (RDC) and puts forth an approach to managing the RDC.

Low-intensity adjusted-dose warfarin for the prevention of hemodialysis catheter failure: a randomized, controlled trial

BACKGROUND AND OBJECTIVES

To determine whether warfarin prolongs the time to first mechanical-catheter failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a multicenter parallel-group randomized controlled trial with blinding of participants, trial staff, clinical staff, outcome assessors, and data analysts. Randomization was in a 1:1 ratio in blocks of four and was concealed by use of fax to a central pharmacy. Hemodialysis patients with newly-placed catheters received low-intensity monitored-dose warfarin, target international normalized ratio (INR) 1.5 to 1.9, or placebo, adjusted according to schedule of sham INR results. The primary outcome was time to first mechanical-catheter failure (inability to establish a circuit or blood flow less than 200 ml/min).

RESULTS

We randomized 174 patients: 87 to warfarin and 87 to placebo. Warfarin was associated with a hazard ratio (HR) of 0.90 (P=0.60; 95% confidence interval [CI], 0.57, 1.38) for time to first mechanical-catheter failure. Secondary analyses were: time to first guidewire exchange or catheter removal for mechanical failure (HR 0.78; 95% CI, 0.37, 1.6); time to catheter removal for mechanical failure (HR 0.67; 95% CI, 0.19, 2.37); and time to catheter removal for any cause (HR 0.89; 95% CI, 0.42, 1.81). Major bleeding occurred in 10 participants assigned to warfarin and seven on placebo (relative risk, 1.43; 95% CI, 0.57, 3.58; P=0.61).

CONCLUSIONS

We found no evidence for efficacy of low-intensity, monitored-dose warfarin in preventing mechanical-catheter failure.

Vascular access for extracorporeal renal replacement therapy in veterinary patients

Vascular access is the first and most basic requirement for successful extracorporeal renal replacement therapy (ERRT). Dual-lumen catheters are the most commonly used method of vascular access for ERRT in veterinary patients. An adequately functioning dialysis catheter allows for smooth and efficient patient management, whereas a poorly functioning catheter frustrates the technician, doctor, and patient. These catheters are fairly quick to place but require meticulous care for optimal function. The most common complications are thrombosis and infection. Monitoring catheter performance should be a routine part of dialysis patient care.

Infecções em cateteres venosos centrais de longa permanência: revisão da literatura

Cateteres venosos de longa permanência são amplamente utilizados em pacientes com necessidade de acesso venoso por período prolongado. A infecção relacionada a esses cateteres permanece um desafio na prática clínica. Revisamos a literatura acerca da epidemiologia e tratamento das infecções relacionadas a cateteres. Staphylococcus aureus é a bactéria mais comumente isolada. Os cateteres semi-implantáveis apresentam taxas de infecção maiores que os totalmente implantáveis. O tratamento pode ser feito com locks, antibioticoterapia sistêmica e até mesmo com retirada do cateter, dependendo do tipo de infecção, do microrganismo isolado e das condições clínicas do paciente. O salvamento do cateter deve ser tentado sempre que possível.

Surface-treated catheters--a review

Almost 30% of prevalent hemodialysis patients use catheters for vascular access although outcomes are superior with the use of either an arteriovenous fistula or a synthetic graft. Catheter complications are a major cause of morbidity and mortality for hemodialysis patients and increase the burden on the health care system. Surface-treated catheters have been developed to combat the three most common causes of catheter failure: infection, fibrin sheath formation, and thrombus formation. Two types of catheter surface treatments are available: antimicrobial coatings and antithrombotic coatings. Surface treatment of central venous catheters with antimicrobial materials reduces both bacterial colonization and the incidence of catheter-related bacteremia in critical care patients by 30-50%. Antithrombotic coatings reduce platelet adhesion, inhibit the inflammatory response, and reduce thrombus formation on coronary stents, ventricular assist devices, central venous catheters, and vascular grafts. However, few reports on the use of surface-treated catheters in the chronic hemodialysis patient population exist. At the present time, it is difficult to justify the increased cost of surface-treated catheters for chronic hemodialysis in the absence of clinical data demonstrating that they reduce catheter-related complications in this patient population.

Dysregulated chemokine receptor expression and chemokine-mediated cell trafficking in pediatric patients with ESRD

BACKGROUND AND OBJECTIVES

Children and adolescents with ESRD on dialysis are susceptible to serious bacterial infections (SBI). Chemokines and chemokine receptors play a critical role in modulating macrophage and neutrophil function. This study examined the hypothesis that expression and/or function of these molecules is dysregulated in patients with ESRD, contributing to leukocyte dysfunction. Design setting, participants, & measurements: Pediatric patients, age 6 mo to 18 yr, with ESRD treated with either hemodialysis or peritoneal dialysis were enrolled in this prospective, nontherapeutic study. Blood was collected for plasma chemokine levels, chemokine receptor profiling by flow cytometry, and functional chemotaxis studies on neutrophils and mononuclear cells.

RESULTS

ESRD in children was associated with reduced expression of the chemokine receptors CXCR1 and chemokine (C-C motif) receptor 2 (CCR2) on circulating neutrophils and monocytes, respectively. When ESRD patients were divided into two subgroups, those who were infection-free and those who had three or more SBI in the preceding year, the differences in chemokine receptor expression were statistically significant compared with control subjects only in those with recurrent infection. In addition to the effects of ESRD on baseline chemokine receptor expression, the hemodialysis procedure itself acutely lowered neutrophil CXCR1 and monocyte CCR2 expression. Furthermore, neutrophil and monocyte responsiveness to chemokine-mediated trafficking signals was impaired in all ESRD patients studied. This abnormality was independent of the level of chemokine receptor expression on the leukocytes.

CONCLUSIONS

The data presented in this study suggest that chemokine receptor dysregulation contributes to leukocyte dysfunction in patients with ESRD. This alteration is especially prominent in ESRD patients with recurrent infection.

Factors affecting long-term survival of tunnelled haemodialysis catheters--a prospective audit of 812 tunnelled catheters

BACKGROUND

In 2001, in the US, 23% of haemodialysis patients were dialysing through tunnelled venous catheters (TVCs), and in the UK (2006) there were 28% of prevalent patients using catheters. It is unlikely that numbers will significantly decrease. We present the results of a prospective audit of the survival of 812 TVCs placed in 492 patients at our institution over a 6-year period (comprising 212 048 patient catheter days or 7068 patient catheter months of follow-up). Four different designs of catheter were studied: Split-Cath III (Medcomp), HemoSplit (Bard), Tesio twin catheter (Medcomp) and Permcath (Quinton).

METHODS

We used Kaplan-Meier survival analysis with log-rank test, to compare the effect of different parameters on catheter survival. The relative importance of significant parameters was determined by Cox regression analysis.

RESULTS

We have shown a significant catheter survival advantage of first catheters over second and subsequent insertions, of right internal jugular site over left internal jugular and thereafter over femoral site, and of non-diabetic over diabetic patients. Patient age, sex and operator (physician in ward-based procedure room under ultrasound control or surgeon in operating theatre under fluoroscopic assistance) did not significantly affect survival. The Permcath design demonstrated inferior survival in all but first catheter insertions in catheter-naïve patients. The HemoSplit and Tesio twin catheter designs demonstrated best survival overall. By Cox proportional hazard modelling the design and the position of the TVC seemed to be the most significant independent survival factors.

CONCLUSIONS

Clinicians need accurate data regarding catheter survival, mode of insertion and design, to inform practice.