Antimicrobial locks: putting the lock on catheter infections

Catheter-related blood stream infection in hemodialysis patients with symmetric tunneled non-side-hole hemodialysis catheters

BACKGROUND

Tunneled hemodialysis catheter-related bloodstream infection is a major cause of morbidity and mortality in end-stage renal disease patients. Side holes positioned near the tip of catheters have been linked to formation of thrombi, which, in turn, have been implicated in predisposition to infection. In addition, side holes allow spillage of catheter locking solution, including antibiotics, thereby minimizing the lock solution's effect on the catheter tip. This study assessed the infection events that occurred in a series of hemodialysis patients using a non-side-hole catheter.

METHODS

Over a period of 2 years, a novel symmetric-tip non-side-hole catheter was placed in 60 patients. Hemodialysis was performed thrice weekly. Prescribed dialyzer flows were 300-350 mL/min. Catheters were routinely locked with heparin 5000 units/mL between treatments. Patients were followed up for any catheter related complications, specifically infection events.

RESULTS

Seven events of catheter-related bloodstream infection occurred for a rate of 0.76 events per 1000 catheter-days, with the first event occurring 9 weeks after insertion. These events were treated by locking the affected catheter with 2 g of clindamycin in 2 mL of heparin 1000 units/mL and administration of intravenous antibiotics, in most cases, for 7-14 days. Two catheters were removed due to infection.

CONCLUSIONS

Catheter-related bloodstream infections with non-side-hole hemodialysis catheters do occur at a relatively low rate and in this initial preliminary study it seems that most of these infections can be successfully treated without removal of the affected catheters.

Effectiveness of Antimicrobial Lock Therapy for the Treatment of Catheter-Related and Central-Line-Associated Bloodstream Infections in Children: A Single Center Retrospective Study

Antimicrobial lock solutions (ALT) in combination with systemic antibiotics can represent a valid option to attempt central venous catheter (CVC) salvage in the case of catheter-related and central-line-associated bloodstream infections (CRBSI and CLABSI). However, data concerning the effectiveness and safety of ALT in children are limited. We aimed to share our center's experience in order to contribute to investigations into the causes of ALT failure in the pediatric population. All children consecutively admitted to Meyer Children's Hospital, University of Florence, Italy, from 1 April 2016 to 30 April 2022, who received salvage ALT to treat an episode of CRBSI/CLABSI, were reviewed. According to ALT failure or success, children were compared with the aim of identifying the risk factors for unsuccessful ALT outcome. Data from 28 children, 37 CLABSI/CRBSI episodes, were included. ALT was associated with clinical and microbiologic success in 67.6% (25/37) of children. No statistically significant differences were observed between the two groups, successes and failures, considering age, gender, reason for use, duration, insertion, type and presence of insertion site infection of the CVC, laboratory data and number of CRBSI episodes. Nevertheless, a trend towards a higher success rate was observed for a dwell time of 24 h for the entire duration of ALT (88%; 22/25 vs. 66.7%; 8/12; p = 0.1827), while the use of taurolidine and the infections sustained by MDR bacteria were associated with a tendency toward greater failure (25%; 3/12 vs. 4%; 1/25; p = 0.1394; 60%; 6/10 vs. 33.3%; 8/24; p = 0.2522). No adverse events, except one CVC occlusion, were observed. ALT combined with systemic antibiotics appears to be an effective and safe strategy for treating children with CLABSI/CRBSI episodes.

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.

How arteriovenous grafts could help to optimize vascular access management

A one-size-fits-all approach to vascular access for dialysis may be prejudicial. Arteriovenous fistulae (AVF) have high primary failure, failure to mature rate, and late-stage complications making them unsuitable choice for many patients. Aging of population with chronic kidney disease (CKD) coupled with venous injury during CKD stages depletes suitable superficial veins for AVF creation. The National Institutes of Health consortium demonstrated the difficulty in attaining a functional AVF in hemodialysis patients. Recognition of flaws in AVF and the quest to reduce catheter use bring to the fore the benefits of arteriovenous grafts (AVG). Advances in catheter technologies, flow, care, and antibiotic locks have resulted in significant improvement in catheter-related infections. However, widespread recognition of catheter-related complications like central vein stenosis, metastatic infections, and exhaustion of venous access sites preclude their being a viable alternative to AVF, furthering the need to explore AVG as a substitute. Placement of "early cannulation" AVG is a catheter sparing option in patients who are likely to have inadequate fistula maturation. Advances in biohybrid technology and tissue-engineered grafts are providing a robust opportunity to develop biocompatible graft materials with minimal tissue reactivity and thrombogenicity. Xenografts (bovine carotid artery grafts) are proving to be comparable and, in many cases, better than conventional polytetrafluoroethylene material. Older age, dialysis dependence, and smaller vein size are related to the appropriateness of AVG creation. An individualized approach in selecting optimal upper extremity vascular access option using patient-specific factors while incorporating the benefits of an AVG would greatly aid in achieving low catheter usage in the dialysis population.

Intravascular Catheters and Biofilm Control

Intravascular catheters are the most common cause of nosocomially acquired bloodstream infections. Bacteria found adhering to the intraluminal surfaces of catheters are the principal source and cause of these infections. Adherent bacteria overtime are known to form multicellular communities which become encased within a three dimensional matrix of extracellular polymeric material known as biofilms, which are thought to be responsible for persistent infections. Consequently, a number of technologies have been developed to help prevent and control biofilms in intravascular catheters. One such approach involves impregnating catheter material with antimicrobial agents. Unfortunately these methods are not universally effective in preventing catheter-related biofilm infections. Technologies that utilise antimicrobials, as catheter locks have been shown to have more potential for preventing biofilm formation and reducing the incidences of catheter related bloodstream infections (CRBSI). This article discusses the significance of biofilms in intravascular catheters and determines whether the treatments available today are proving to be effective for controlling biofilms and draws attention to future avenues which are being investigated to control biofilms and therefore CRBSI.

Bacterial adherence and biofilm formation on medical implants: a review

Biofilms are a complex group of microbial cells that adhere to the exopolysaccharide matrix present on the surface of medical devices. Biofilm-associated infections in the medical devices pose a serious problem to the public health and adversely affect the function of the device. Medical implants used in oral and orthopedic surgery are fabricated using alloys such as stainless steel and titanium. The biological behavior, such as osseointegration and its antibacterial activity, essentially depends on both the chemical composition and the morphology of the surface of the device. Surface treatment of medical implants by various physical and chemical techniques are attempted in order to improve their surface properties so as to facilitate bio-integration and prevent bacterial adhesion. The potential source of infection of the surrounding tissue and antimicrobial strategies are from bacteria adherent to or in a biofilm on the implant which should prevent both biofilm formation and tissue colonization. This article provides an overview of bacterial biofilm formation and methods adopted for the inhibition of bacterial adhesion on medical implants.

Prevention of hemodialysis catheter-related blood stream infections using a cotrimoxazole-lock technique

ABSTRACT 

Background & aim: This trial assessed the efficacy of cotrimoxazole lock solution in reducing catheter-related blood stream infections (CRBSIs) among hemodialysis (HD) patients who were dialyzed using tunneled catheters. Method: Patients randomly received either heparin (2500 U/ml) (control group) or a mixture of 10 mg/ml cotrimoxazole (based on trimethoprim) and 2500 U/ml heparin (antibiotic group) as catheters lock solution. Results: Compared with the control group, CRBSIs rates per 1000 catheter-days was significantly lower (0.58 vs 4.4 events; p = 0.002) and cumulative infection-free catheter survival was significantly higher (log rank statistic 5.88; p = 0.015) in the antibiotic group. There were no statistical differences regarding incidences of catheter removal (8.7% in the antibiotic group vs 22% in the control group; p = 0.116) or thrombosis (2.2% in the antibiotic group vs 9.8% in the control group; p = 0.129) between the two groups. Conclusion: cotrimoxazole containing catheter lock solution is effective in reducing CRBSIs incidence and prolonging dialysis catheter survival in HD patients.

Comparison of ML8-X10 (a prototype oil-in-water micro-emulsion based on a novel free fatty acid), taurolidine/citrate/heparin and vancomycin/heparin antimicrobial lock solutions in the eradication of biofilm-producing staphylococci from central venous catheters

OBJECTIVES

Antimicrobial lock solutions are used for prevention and management of catheter-related bloodstream infections. ML8-X10 (a prototype oil-in-water micro-emulsion based on a novel free fatty acid), vancomycin/heparin and taurolidine/citrate/heparin (Taurolock™-Hep500) lock solutions were tested against biofilm-forming Staphylococcus epidermidis and methicillin-susceptible Staphylococcus aureus.

METHODS

MICs were tested in neutral broth (pH ~7) and acidified broth (pH 5). In an established in vitro central venous catheter (CVC) lock model, solutions were introduced after 24 h of bacterial growth in a CVC incubated at 37°C. After an additional 8, 24 or 72 h of incubation, saline flush and cut catheter segments were processed for bacterial quantification. The cfu/mL at 0 h was subtracted from cfu/mL at the different timepoints.

RESULTS

The activities of ML8-X10 and taurolidine solutions were enhanced at lower pH (P < 0.05). Against S. epidermidis, ML8-X10 solution demonstrated less activity than taurolidine at 8 h (P < 0.001), but was not significantly different from vancomycin. At 24 h, ML8-X10 solution demonstrated significantly less activity than taurolidine (P < 0.001), but was significantly more active than vancomycin (P < 0.001). Against S. aureus, ML8-X10 solution was less active than taurolidine at 8 and 24 h (P < 0.001 for both), but was similar to vancomycin. At 72 h, all lock solutions reduced colony counts to levels that approached or reached the limit of detection against both strains.

CONCLUSIONS

In our in vitro catheter lock model, the novel free fatty acid emulsion demonstrated activity against biofilm-forming staphylococci similar to or greater than that of vancomycin lock solution. Taurolidine was the most active lock solution at 8 and 24 h, with all lock solutions tested demonstrating high activity at 72 h.

Comparative effectiveness of two catheter locking solutions to reduce catheter-related bloodstream infection in hemodialysis patients

BACKGROUND AND OBJECTIVES

Infection is the second leading cause of death in hemodialysis patients. Catheter-related bloodstream infection and infection-related mortality have not improved in this population over the past two decades. This study evaluated the impact of a prophylactic antibiotic lock solution on the incidence of catheter-related bloodstream infection and mortality.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This prospective, multicenter, observational cohort study compared the effectiveness of two catheter locking solutions (gentamicin/citrate versus heparin) in 555 hemodialysis patients dialyzing with a tunneled cuffed catheter between 2008 and 2011. The groups were not mutually exclusive. Rates of catheter-related bloodstream infection and mortality hazards were compared between groups.

RESULTS

The study population (n=555 and 1350 catheters) had a median age of 62 years (interquartile range=41-83 years), with 50% men and 71% black. There were 427 patients evaluable in the heparin period (84,326 days) and 322 patients evaluable in the antibiotic lock period (71,192 days). Catheter-related bloodstream infection in the antibiotic lock period (0.45/1000 catheter days) was 73% lower than the heparin period (1.68/1000 catheter days; P=0.001). Antibiotic lock use was associated with a decreased risk of catheter-related bloodstream infection compared with heparin (risk ratio, 0.23; 95% confidence interval, 0.13 to 0.38 after multivariate adjustment). Cox proportional hazards modeling found that antibiotic lock was associated with a reduction in mortality (hazard ratio, 0.36; 95% confidence interval, 0.22 to 0.58 in unadjusted analyses; hazard ratio, 0.32; 95% confidence interval, 0.14 to 0.75 after multivariate adjustment). The rate of gentamicin-resistant organisms decreased (0.40/1000 person-years to 0.22/1000 person-years) in the antibiotic lock period (P=0.01).

CONCLUSIONS

The results of this study show that the use of a prophylactic, gentamicin/citrate lock was associated with a substantial reduction in catheter-related bloodstream infection and is the first to report a survival advantage of antibiotic lock in a population at high risk of infection-related morbidity and mortality.

The economics of hemodialysis catheter-related infection prophylaxis

Hemodialysis central venous catheter (CVC) use is associated with the highest morbidity, mortality, and cost of all types of hemodialysis vascular access. CVC-related infection drives much of the cost associated with CVC use. The magnitude of the cost associated with CVC-related infection varies depending on the type and severity of that infection; however, estimates of the total direct and indirect costs associated with hospitalizations due to hemodialysis CVC-related infections range from 17,000 USD to 32,000 USD per episode. Thus, it is critically important, to not only have effective strategies to limit CVC-related infection but also evaluate whether these strategies are an efficient use of resources. Prophylactic strategies can be considered economically efficient only if the value of its implementation and the corresponding drop in infection rate offer greater value than standard care. The optimal CVC-related infection prophylaxis strategy should work to limit infection risk with minimal risk, inconvenience, and discomfort to the patient, and at minimal cost. The aim of this review was to examine the clinical and economic impact of some commonly described interventions used for CVC infection prophylaxis.

Preventing catheter-related infections in children undergoing hemodialysis

The increased use of tunneled cuffed catheters in children on chronic hemodialysis is the result of their relative ease of insertion, pain-free dialysis and immediate use. The disadvantage of their use is that they are associated with catheter-related bacteremia (CRB), which in turn is related with increased morbidity, access loss and occasionally metastatic infections and even death. A CRB might be difficult to diagnose and is often associated with a previous history of CRB, exit-site infection, low serum albumin and long duration of catheter use. There is evidence that the use of arteriovenous fistulae is associated with lower infection rates. The implementation of effective strategies for the prevention of CRBs include the adoption of policies for improving arteriovenous fistula rates, appropriate surgical catheter insertion and optimal nursing care of the exit site, and a safe connection technique. Recently, the effectiveness of antimicrobial catheter solutions for preventing CRB has been documented in a number of randomized clinical trials. In addition, the application of antibiotic ointments at the exit sites of tunneled cuffed catheters might be significant for the reduction of Staphylococcus-related CRB. The upside is that education-based programs combining specific preventive measures can significantly reduce CRBs.

Inhibition of bacterial adhesion on medical devices

Microbial infections resulting from bacterial adhesion to biomaterial surfaces have been observed on almost all medical devices. Biofilm infections pose a number of clinical challenges due to their resistance to immune defence mechanisms and antimicrobials, and, regardless of the sophistication of the implant, all medical devices are susceptible to microbial colonisation and infection. Research efforts are currently directed towards eliminating or reducing infection of medical devices. Strategies to prevent biofilm formation include physiochemical modification of the biomaterial surface to create anti-adhesive surfaces, incorporation of antimicrobial agents into medical device polymers, mechanical design alternatives, and release of antibiotics. Nevertheless, the success of these alternatives has been modest, mainly due to the various environments into which devices are placed and the diversity of ways in which organisms can colonise surfaces. Biosurfactants have been reported as a promising strategy as they effectively inhibit bacterial adhesion and retard biofilm formation, and are thus potentially useful as a new generation of anti-adhesive and antimicrobial coatings for medical devices.

Prevention of catheter-related bacteremia in children on hemodialysis: time for action

This editorial commentary discusses the strategies for prevention of catheter-related bacteremia (CRB) in children on hemodialysis, which is associated with high morbidity and the increase of hospital cost. There is evidence that the use of arteriovenous fistulae in children on hemodialysis is associated with lower infection rates. Therefore, the use of catheters in these patients should be decreased by improving arteriovenous fistulae use rates or by increasing peritoneal dialysis patient recruitment. However, despite the wide adoption of such policies, hemodialysis catheters are still being used in a significant number of cases. For these patients, implementation of effective strategies for preventing contamination of the catheter hub should be a priority. The appropriate recording and evaluation of CRB rates are important for assessing preventive policies. In addition, the successful management of a CRB is essential for preventing recurrence of bacteremia. Recently it was documented in a number of randomized clinical trials that antimicrobial lock solutions were effective for preventing CRB. It is suggested that the use of antimicrobial locks should be considered in children who are at high risk of developing CRB, with caution for their long-term use, because of the possibility of bacterial resistance. Now is the time for action, and all preventive steps should be performed simultaneously to minimize the risk of CRB.

Systematic review of antimicrobials for the prevention of haemodialysis catheter-related infections

BACKGROUND

Almost 30% of chronic haemodialysis (HD) patients are dependent on central venous catheters (CVCs) for their vascular access, and catheter-related bacteraemia (CRB) is the major reason for catheter loss and has been associated with substantial morbidity, including meta-static infections. This systematic review evaluates the benefits and harms of antimicrobial interventions for the prevention of catheter-related infections (CRIs).

METHODS

MEDLINE (1950-May 2009), EMBASE (1980-May 2009) CENTRAL (up to May 2009) and bibliographies of retrieved articles were searched for relevant RCTs. Analysis was by a random effects model and results expressed as rate ratio, relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI).

RESULTS

A total of 29 trials with 2886 patients and 3005 catheters were included. Antimicrobial catheter locks (AMLs) significantly reduced the rates of CRBs (rate ratio, 0.33, 95% CI 0.24-0.45) and exit-site infections (ESIs) (rate ratio 0.67, 95% CI 0.47-0.96). Exit-site antimicrobial application also significantly reduced the rates of CRBs (rate ratio 0.21, 95% CI 0.12-0.36) and ESIs (rate ratio 0.22, 95% CI 0.10-0.47). Antimicrobial coating of HD catheters and the use of peri-operative antimicrobials did not result in significant reduction in rates of CRBs and ESIs.

CONCLUSION

The use of AMLs and exit-site antimicrobials are useful measures in the reduction of CRIs, whereas antimicrobial impregnated catheters and peri-operative systemic antimicrobial administration have not been found to be beneficial. Further head-to-head trials of various AMLs and exit-site antimicrobials are needed to know about their comparative clinical efficacy.

Combining novel technologies with improved logistics to reduce hemodialysis vascular access dysfunction

Hemodialysis (HD) vascular access dysfunction is currently a huge clinical problem for which there are no effective therapies. There are, however, a number of promising technologies that are currently at the experimental or clinical trial stage. We believe that the application of these novel technologies in combination with better clinical protocols for vascular access care could significantly reduce the current problems associated with HD vascular access.

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.

Methods. The tested solution (C/MB/P comprising 7% sodium citrate, 0.05% methylene blue and 0.165% parabens) and individual components were challenged against gram-positive and gram-negative organisms and fungi. Control solutions were heparin with preservatives. Studies included evaluation of eradication of planktonic bacteria and sessile organisms in a biofilm grown on polymeric and glass coupons. Biofilm samples were inspected by scanning electron microscopy, atomic force microscopy and vital stains.

Results. The C/MB/P solution, contrary to heparin, kills most tested planktonic microorganisms within 1 h of incubation. All tested organisms have an MIC of 25% or less of the original concentration of a new catheter lock. Bacteria strains did not develop resistance over more than 40 passages of culture suspensions. The C/MB/P solution is able to kill nearly all sessile bacteria in biofilm growth on plastic or glass discs in 1 h. Microscopic methods demonstrated extensive physical elimination of biofilm deposits from treated coupons. In contrast, heparin had a minimal effect on planktonic or biofilm organisms.

Conclusions. The new multicomponent lock solution has strong antimicrobial properties against both planktonic and sessile microorganisms. By comparison, heparin with preservative has weak antibacterial properties against planktonic and biofilm bacteria. The tested catheter lock may have usefulness in preventing bacterial colonization of haemodialysis catheters and diminishing the incidence of catheter-related bacteraemia.

Effect of antimicrobial locks for tunneled hemodialysis catheters on bloodstream infection and bacterial resistance: a quality improvement report

BACKGROUND

Catheter-restricted antimicrobial lock (AML) use reduces catheter-associated bloodstream infection (CA-BSI) in clinical trial settings, but may not be as effective in clinical settings and may increase bacterial resistance.

DESIGN

Quality improvement report analyzed using a cross-sectional time series (unbalanced panel) design.

SETTING & PARTICIPANTS

The study cohort comprised all prevalent adults treated with hemodialysis through a tunneled catheter for any, but not necessarily all, of the time from January 1, 2003, to June 30, 2006, in Manukau City, New Zealand (135,346 catheter-days, 404 tunneled catheters, 320 patients).

QUALITY IMPROVEMENT PLAN

Catheter-restricted AMLs (heparin plus gentamicin) for all tunneled catheters from July 1, 2004.

MEASURES

Repeated observations of CA-BSI, hospitalization, tunneled catheter removal, and death from CA-BSI analyzed by using generalized estimating equations with a single level of clustering for each tunneled catheter and patterns of bacterial resistance analyzed by using simple descriptive statistics.

RESULTS

AML use was associated with reductions in rates of CA-BSI and hospitalization for CA-BSI by 52% and 69% for patients with tunneled catheters locked continuously with AMLs since their insertion compared with those with tunneled catheters that were not, respectively. AML exposure also was associated with a trend to increased gentamicin resistance amongst coagulase-negative staphylococci isolates, a pattern similar to that observed for BSIs in our general hemodialysis population in which tunneled catheters were not the source of BSI, but different from that in the general non-end-stage renal disease population in the region.

LIMITATIONS

This is an uncontrolled observational study and cannot prove causality. The follow-up period of 18 months is longer than for other studies, but still too short to definitely answer whether AML use drives bacterial resistance.

CONCLUSIONS

A change to use of AMLs may improve clinical outcomes; however, additional study of associated bacterial resistance is needed before AML use becomes standard care.

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.

Bacterial and fungal biofilm infections

Biofilms are communal structures of microorganisms encased in an exopolymeric coat that form on both natural and abiotic surfaces and have been associated with a variety of persistent infections that respond poorly to conventional antibiotic chemotherapy. Biofilm infections of certain indwelling medical devices by common pathogens such as staphylococci are not only associated with increased morbidity and mortality but are also significant contributors to the emergence and dissemination of antibiotic resistance traits in the nosocomial setting. Current treatment paradigms for biofilm-associated infections of semipermanent indwelling devices typically involve surgical replacement of the device combined with long-term antibiotic therapy and incur high health care costs. This review summarizes the existing data relating to the nature, prevalence, and treatment of biofilm-associated infections and highlights experimental approaches and therapies that are being pursued toward more effective treatments.

Extracorporeal photopheresis with permanent subcutaneous right atrial catheters

BACKGROUND

Adequate peripheral venous access is crucial for successful extracorporeal photopheresis (ECP). As this approach is not always feasible in older patients and patients with graft-versus-host disease, central venous catheters play an increasing role in providing long-term vascular access for ECP.However, not all catheters are able to deliver the minimum flow rate of 7 ml/min for ECP.

PATIENTS AND METHODS

Eight different permanent subcutaneous right atrial catheters were connected in vitro to the UVAR-XTS photopheresis system and median flow rates were determined. In addition, in vivo flow rates of patients who received ECP, using either peripheral or central venous access, were determined.

RESULTS

Hemodialysis catheters with an internal diameter of 2.0 or 1.5 x 3.5 mm and a length up to 48 cm provided in vitro flow rates of 27-28 ml/min, almost identical to a peripheral access needle. Central venous catheters with a length of over 90 cm reached flow rates below 7 ml/min and are impractical for ECP. The analysis of 308 ECP collection cycles with peripheral vascular access revealed an average flow rate of 31.5 +/- 6.4 ml/min. Only permanent subcutaneous right atrial catheters made for hemodialysis provided similar flow rates (Quinton PermCath Dual Lumen) (33.7 +/- 4.7 ml/min, n = 198).

CONCLUSIONS

Permanent subcutaneous hemodialysis catheters with a length of maximally 48 cm achieve optimal flow rates for ECP. They represent therefore the central venous access of choice in patients with inadequate peripheral vascular access.