Central venous catheter infection in adults in acute hospital settings

As well as the human cost, central venous catheter (CVC)-related bloodstream infections significantly inflate hospital costs, mainly through increased length of stay in hospital, particularly in intensive care. This literature review appraises recent research on measures used to minimize CVC-related infection and compares it with current best practice. Randomized controlled trials and systematic reviews published on the subject between 2000 and 2005 were reviewed, concentrating on non-tunnelled, short-term CVCs in the acute hospital setting. The new evidence mainly backs up current best practice. However, skin disinfection could be improved by using alcoholic chlorhexidine followed by aqueous povidone-iodine before CVC insertion. Also, alcoholic chlorhexidine is the preferred solution for cleaning the hubs/connectors before accessing the CVC. Good hand hygiene and quality control and education programmes are vital to improve patient care. More research is needed to clarify the effectiveness of certain interventions and technologies, such as antimicrobial CVCs.     

Combined skin disinfection with chlorhexidine/propanol and aqueous povidone-iodine reduces bacterial colonisation of central venous catheters

Objective Central venous catheter (CVC)-related infections may be caused by micro-organisms introduced from the skin surface into deeper tissue at the time of CVC insertion. The optimal disinfection regimen to avoid catheter-related infections has not yet been defined. This study compares three different approaches.Design Prospective randomised trial.Setting A tertiary care hospital.Patients and participants One hundred nineteen patients scheduled electively to receive 140 CVCs.Interventions Skin disinfection was performed with either povidone-iodine 10% (PVP-iodine), chlorhexidine 0.5%/propanol 70%, or chlorhexidine 0.5%/propanol 70% followed by PVP-iodine 10%. Prior to disinfection, a swab from the site of insertion was taken for culture. CVCs were removed if no longer needed or infection was suspected. All catheters were cultured quantitatively after removal.Measurement and results Bacteria could be isolated from 20.7% of the catheter tips. Bacterial growth was found in 30.8% of the catheters placed after skin disinfection with povidone-iodine, in 24.4% after disinfection with propanol/chlorhexidine and in 4.7% after disinfection with propanol/chlorhexidine followed by povidone-iodine (p=0.006). In 15 cases, the same organism was isolated from the skin swab and the catheter tip. Ten of these paired isolates showed the same pattern in a pulsed-field gel electrophoresis analysis.Conclusions Skin disinfection with propanol/chlorhexidine followed by PVP-iodine was superior in the prevention of microbial CVC colonisation compared to either of the regimens alone. These results support the concept that catheter infections can originate from bacterial translocation at the time of catheter insertion.     

Colonization of central venous catheters

We studied etiologic factors important in colonization of 179 central venous catheters (CVCs) in patients randomized into group 1 (who received daily topical applications of povidone-iodine) or group 2 (who received only dry dressing changes). Colonization rates of CVC tips were similar between group 1 (18/84 or 21%) and group 2 (22/95 or 23%). Peripheral blood cultures grew Candida in eight hyperalimented patients (evenly divided between groups 1 and 2), S epidermidis in four other patients (also evenly divided), and gram-negative bacteria in three patients. Colonization rates for CVCs in place for 0 to seven days was 15.6% (17/109) and 76.7% (23/30) if used from eight to 30 days. Inflammatory signs at CVC sites were often absent when CVCs became colonized or produced bacteremia. Unimportant determinants of CVC colonization included skin securement of CVCs, antibiotic infusions through CVC lines, and masking and gowning of physicians before CVC placement. Daily applications of povidone-iodine did not reduce colonization of CVCs as compared to dry dressing changes.     

Bench-to-bedside review: Challenges of diagnosis,care and prevention of central catheter-related bloodstream infections in children

Central venous catheters (CVCs) are indispensable in modern pediatric medicine. CVCs provide secure vascular access, but are associated with a risk of severe complications, in particular bloodstream infection. We provide a review of the recent literature about the diagnostic and therapeutic challenges of catheter-related bloodstream infection (CRBSI) in children and its prevention. Variations in blood sampling and limitations in blood culturing interfere with accurate and timely diagnosis of CRBSI. Although novel molecular testing methods appear promising in overcoming some of the present diagnostic limitations of conventional blood sampling in children, they still need to solidly prove their accuracy and reliability in clinical practice. Standardized practices of catheter insertion and care remain the cornerstone of CRBSI prevention although their implementation in daily practice may be difficult. Technology such as CVC impregnation or catheter locking with antimicrobial substances has been shown less effective than anticipated. Despite encouraging results in CRBSI prevention among adults, the goal of zero infection in children is still not in range. More high-quality research is needed in the field of prevention, accurate and reliable diagnostic measures and effective treatment of CRBSI in children.     

Central venous catheters: preventing infection and occlusion

As central venous catheters (CVCs) become more widely used in today's healthcare environment, nurses require expert knowledge in relation to CVC maintenance to prevent complications and maximize efforts to optimize the individual's health status. This is especially so since CVCs have begun to be used outside intensive care units, e.g. in general wards, and can be associated with high incidences of infection, occlusion and subsequent compromise in patient health. Nurses are responsible for the maintenance and use of central access devices, such as CVCs, resulting in a need for literature specific to the nursing aspects of CVC management. This article addresses many nursing issues pertaining to care of the central line, focusing on evidence- and research-based literature, and also reviews the literature to make recommendations for practice.     

Rifampicin-impregnated central venous catheters: a meta-analysis of randomized controlled trials

BACKGROUND: The use of antimicrobial-impregnated central venous catheters (CVCs) for the prevention of CVC microbial colonization and catheter-related bloodstream infection (CRBSI) remains controversial. METHODS: We performed a meta-analysis of randomized controlled trials (RCTs) evaluating CRBSI and colonization of CVCs impregnated with rifampicin-based antimicrobial combinations. Our main analysis compared the occurrence of CRBSI with rifampicin/minocycline-impregnated CVCs with that of non-rifampicin-impregnated CVCs. The PubMed and Cochrane Central Register of Controlled Trials databases were searched (until October 2006). RESULTS: Eight RCTs were included in the analysis. The main analysis (seven RCTs) demonstrated that rifampicin/minocycline-impregnated CVCs were associated with fewer CRBSIs compared with catheters not impregnated with rifampicin/minocycline (OR 0.23, 95% CI 0.14-0.40). The same was true regarding colonization (OR 0.46, 95% CI 0.31-0.69). Further analysis, comparing rifampicin-based CVCs with non-rifampicin-impregnated CVCs, demonstrated superiority of rifampicin-based CVCs in reducing colonization (OR 0.38, 95% CI 0.24-0.62) and CRBSI (OR 0.24, 95% CI 0.14-0.40). Similar results, suggesting superiority of rifampicin/minocycline-impregnated CVCs, were noted in a subgroup analysis of colonization and CRBSIs in which rifampicin/minocycline-impregnated CVCs were compared with simple, non-tunnelled, non-antimicrobially impregnated CVCs, a subgroup analysis that was performed by excluding low quality RCTs, and a subgroup analysis for colonization comprising studies in which the sonication technique was used. No serious adverse events and no difference in mortality between the two treatment groups were reported. No clear conclusions can be made regarding the impact of the use of rifampicin/minocycline-impregnated CVCs on the development of antimicrobial resistance based on the available data. CONCLUSIONS: The available evidence suggests that rifampicin/minocycline-impregnated CVCs are safe and effective in reducing the rate of catheter colonization and CRBSI. Further research should focus on the possible development of resistance and on pharmacoeconomic issues related to the use of rifampicin/minocycline-impregnated CVCs.     

Elective removal of cuffed central venous catheters in children

Background Subcutaneously tunneled, cuffed central venous catheters (CVCs) are commonly used in children undergoing cytotoxic chemotherapy or hematopoietic stem-cell transplantation. When their use is no longer indicated or precluded by mechanical or infectious complications, CVCs have to be removed. General instructions on how cuffed CVC should be removed are available in the medical texts but none is adapted for use in children. Materials and methods A literature search from the MEDLINE and EMBASE to identify articles describing the procedure of removing CVC or complications arising from the procedure was carried out. Results Specific guidance on the removal of CVC in children was not found. Venous air embolism appeared to be the most common complication associated with catheter removal but none involved pediatric patients. On the other hand, three out of the five incidents of catheter fracture with or without embolization happened in children. Conclusion Further studies are needed to define the optimal management of CVC removal in pediatric patients. A sequence of positioning the child, use of sedation, dissecting out the cuff, pulling off the catheter, closing the exit wound, and handling of the removed catheter is suggested.     

Venous air embolism from central venous catheterization: a need for increased physician awareness.

OBJECTIVES: To report a series of patients with clinically diagnosed venous air embolism (VAE) and major sequelae as a complication of the use of central venous catheters (CVCs), to survey health care professionals' practices regarding CVCs, and to implement an educational intervention for optimizing approaches to CVC insertion and removal. SETTING: Tertiary care, university-based 806-bed medical center. INTERVENTIONS: We surveyed 140 physicians and 53 critical care nurses to appraise their awareness of the proper management and complications of CVCs. We then designed, delivered, and measured the effects of a multidisciplinary educational intervention given to 106 incoming house officers. MEASUREMENTS AND MAIN RESULTS: Although most physicians (127, 91%) chose the Trendelenburg position for CVC insertion, only 42 physicians (30%) reported concern for VAE. On CVC removal, only 36 physicians (26%) cited concern for VAE. Some physicians (13, 9%) reported elevating the head of the bed during CVC removal, possibly increasing the risk of VAE. Awareness of VAE or its prevention did not correlate with the level of physician training, experience, or specialty. After the educational intervention, concern for and awareness of proper methods of prevention of VAE improved (p < .001). At 6-month follow-up, reported use of the Trendelenburg position continued, but concern cited for VAE had returned to baseline. CONCLUSIONS: There is inadequate awareness of VAE as a complication of CVC use. Focused instruction can improve appreciation of this potentially fatal complication and knowledge of its prevention, but the effect declines rapidly. To achieve a more sustained improvement, a more intensive, hands-on, periodic educational program will likely be necessary, as well as reinforcement through enhanced supervision of CVC insertion and removal practices.     

Central venous catheter use

Central venous catheters (CVCs) are used with increasing frequency in the intensive care unit and in general medical wards. Catheter infection, the most frequent complication of CVC use, is associated with increased morbidity, mortality, and duration of hospital stay. Risk factors in the development of catheter colonisation and bloodstream infection include patient factors (increased risk associated with malignancy, neutropenia, and shock) and treatment-related factors (increased risk associated with total parenteral nutrition, ICU admission for any reason, and endotracheal intubation). Other risk factors are prolonged catheter indwelling time, lack of asepsis during CVC insertion, and frequent manipulation of the catheter. The most important factor is catheter care after placement. Effects of CVC tunnelling on infection rates depend to a large extent on indwelling time and the quality of catheter care. Use of polyurethane dressings can increase the risk of colonisation compared to regular gauze dressing. Thrombus formation around the CVC tip increases the risk of infection; low-dose anticoagulants may decrease this risk. New developments such as CVC impregnation with antibiotics may reduce the risk of infection. Reducing catheter infection rates requires a multiple-strategy approach. Therefore, ICUs and other locations where CVCs are used should implement strict guidelines and protocols for catheter insertion, care, and maintenance.     

The safety of prolonging the use of central venous catheters: a prospective analysis of the effects of using antiseptic-bonded catheters with daily site care

OBJECTIVE: To determine rates of catheter colonization and catheter-related bloodstream infection (CRBSI) when antiseptic-bonded central venous catheters (CVCs) and standardized daily site care are used with no predetermined interval for removal. DESIGN: Prospective observational study. SETTING: Two major trauma centers. PATIENTS: All trauma patients admitted to two major trauma centers that received a CVC from May 1996 through May 1998. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Catheters were semiquantitatively cultured to identify bacterial colonization and CRBSI. Monitored variables included total catheter days, anatomical site of catheter insertion, and area in hospital of catheter insertion. CVC tips and intracutaneous segments were semiquantitatively cultured. A total of 460 (92%) of 501 catheters placed in 324 trauma patients were evaluable, representing 95.5% of all catheter days during the study period. Rates of catheter colonization and CRBSI were 5% (5/1000 catheter days) and 1.5% (1.511000 catheter days), respectively. Subclavian catheters were in place longer than femoral or internal jugular catheters (p < .0001), but the colonization rate was significantly lower (p = .03; relative risk, 0.34; 95% confidence interval, 0.15-0.77). No differences in CRBSI rates among anatomical sites or between catheters used < or =14 days and those used >14 days were identified. CONCLUSION: Femoral and internal jugular antiseptic-bonded CVCs develop bacterial colonization earlier than subclavian CVCs. Subclavian antiseptic-bonded CVCs combined with standardized daily site care may be safely used >14 days in trauma patients.     

The microbiological and clinical outcome of guide wire exchanged versus newly inserted antimicrobial surface treated central venous catheters

Introduction

The management of suspected central venous catheter (CVC)-related sepsis by guide wire exchange (GWX) is not recommended. However, GWX for new antimicrobial surface treated (AST) triple lumen CVCs has never been studied. We aimed to compare the microbiological outcome of triple lumen AST CVCs inserted by GWX (GWX-CVCs) with newly inserted triple lumen AST CVCs (NI-CVCs).

Methods

We studied a cohort of 145 consecutive patients with GWX-CVCs and contemporaneous site-matched control cohort of 163 patients with NI-CVCs in a tertiary intensive care unit (ICU).

Results

GWX-CVC and NI-CVC patients were similar for mean age (58.7 vs. 62.2 years), gender (88 (60.7%) vs. 98 (60.5%) male) and illness severity on admission (mean Acute Physiology and Chronic Health Evaluation (APACHE) III: 71.3 vs. 72.2). However, GWX patients had longer median ICU lengths of stay (12.2 vs. 4.4 days; P < 0.001) and median hospital lengths of stay (30.7 vs. 18.0 days; P < 0.001). There was no significant difference with regard to the number of CVC tips with bacterial or fungal pathogen colonization among GWX-CVCs vs. NI-CVCs (5 (2.5%) vs. 6 (7.4%); P = 0.90). Catheter-associated blood stream infection (CA-BSI) occurred in 2 (1.4%) GWX patients compared with 3 (1.8%) NI-CVC patients (P = 0.75). There was no significant difference in hospital mortality (35 (24.1%) vs. 48 (29.4%); P = 0.29).

Conclusions

GWX-CVCs and NI-CVCs had similar rates of tip colonization at removal, CA-BSI and mortality. If the CVC removed by GWX is colonized, a new CVC must then be inserted at another site. In selected ICU patients at higher central vein puncture risk receiving AST CVCs GWX may be an acceptable initial approach to line insertion.     

Urokinase for restoring patency of malfunctioning or blocked central venous catheters in children with hemato-oncological diseases

Goals of work To evaluate differences in success rate between two dosages of intraluminal urokinase (IL-UK) for treatment of withdraw occlusion in central venous catheters (CVC) and to confirm the efficacy of a salvage protocol with low-dose systemic urokinase (S-UK) in case of failure of IL-UK or of complete catheter obstruction.Patients and methods All malfunctioning or occluded partially implanted indwelling catheters inserted in a 29-month period in children with cancer at two tertiary care centers (Genoa and Turin) in Italy were eligible for this study. In cases of withdraw occlusion, IL-UK was used as first-line treatment with different schedules of administration in the two centers: a 5,000 IU/ml dose was used in Genoa and a 25,000 IU/ml dose in Turin (Protocol A). In case of failure of the front-line protocol or in case of complete CVC occlusion, S-UK at 1,000 IU/kg per hour for 3 h was used as a salvage protocol in both centers (Protocol B).Main results There were 81 episodes of malfunction and three of occlusion recorded in 68 CVCs. Protocol A was successful in 75 (92.5%) of the malfunction episodes. In particular, the dose of 5,000 IU of IL-UK was successful in 42 (89%) CVCs while the 25,000 IU dose resolved 33 (97%) of the episodes (not significant). The six patients with CVC refractory to IL-UK and the three subjects with complete CVC occlusion were treated with S-UK. Patency was obtained in seven cases (78%); the remaining two catheters had to be removed.Conclusions We found that 5,000 IU of IL-UK were as effective as 25,000 IU to resolve withdrawal occlusion in partially implanted CVCs and that systemic treatment with urokinase may rescue a significant proportion of CVCs refractory to IL-UK or that are apparently completely occluded.     

A simplified method of antibiotic lock therapy for Broviac–Hickman catheters using a CLC 2000 connector device

Introduction We report a simplified method of performing antibiotic lock therapy (ALT) based on a disposable central venous catheter (CVC) hub device, CLC 2000, enabling an open-ended CVC to be flushed with normal saline solution without heparin. Methods ALT was administered through a CLC 2000 connector for recurrent CVC-bloodstream infections (BSI) by the same organism in four patients and for CVC colonization in five patients. Results The antibiotic concentration obtained in the lumen of the CVC with ALT was 2,500-fold higher than the minimum inhibiting concentration of targeted bacteria for patients treated with vancomycin, 2,500–80,000-fold higher for patients treated with teicoplanin, and 10,000-fold higher for the patient treated with amikacin. All CVC-BSIs treated with ALT resulted in complete clinical and microbiological responses. No case of malfunction in withdrawing or flushing the CVC and no precipitation during the administration of the antibiotic solution was observed. No recurrence of CVC-BSI or CVC colonization by the same organism was diagnosed during subsequent follow-up, despite the fact that all patients had further periods of severe neutropenia. At the last follow-up, three CVCs had been removed for other infections (fever of unknown origin in two; fungemia in one), four CVCs had been removed at the end of therapy, and one CVC is still in situ 20 months after ALT. Conclusions In conclusion, a course of ALT is feasible in cancer patients with infected but much-needed CVCs before resorting to removal. The use of the CLC 2000 connector device simplifies the procedure for preparation and administration of ALT without compromising its efficacy.     

Central venous catheter infections in patients with acute leukemia

BACKGROUND: Central venous catheters (CVCs) have become an essential tool for an appropriate management of patients with acute leukemia. Infectious complications are a major concern in patients treated for acute leukemia. Although CVC-related infections are considered to be a major source of infections during neutropenia (<500/microl), data regarding the incidence of CVC-related infections are rare in acute leukemia. PATIENTS AND METHODS: We analyzed nontunneled CVCs in 58 patients with acute leukemia (22 men/36 women) in 119 chemotherapy cycles from April 1996 to January 1998 in a prospective trial. Proven CVC-related infection was defined as the isolation of the same organism from peripheral blood and CVC tip. CVC infection was suspected or possible when exit site inflammation and positive blood culture or organisms typical for CVC infection were observed. RESULTS: Mean neutropenia/cycle was 16.3 days (SD 8.0). 178 CVCs with 2,576 CVC days (mean 14.5 days, SD 7.2 days) were used in 119 cycles. Fever occurred in 87 cycles (73%). Blood stream infection was proven in 31 out of 87 febrile episodes (26.1%) with 40 isolates (8 gram-negative, 31 gram-positive, 1 Candida spp.). Colonization of the CVC tip was observed in 24 CVC lines with 28 isolates (27 gram-positive, 1 gram-negative); however, proven CVC-related infections were observed in 5 episodes only, all with coagulase-negative staphylococci. In another 6 episodes, CVC-related infection was assumed (local inflammation and gram-positive blood culture). Six further episodes had typical blood isolates (4 coagulase-negative staphylococci, 1 Candida spp.) and were considered possible CVC-related infections. In none of the remaining afebrile 32 cycles was a CVC infection observed or suspected. CONCLUSION: Gram-positive organisms contributed to the majority of CVC-related infections (16 out 17 CVC infections); however, the overall incidence of CVC infections in acute leukemia patients was 6.5/1,000 CVC days only (1.9 proven/2.3 suspected/2.3 possible/1,000 CVC days).     

Inflammation at the insertion site is not predictive of catheter-related bloodstream infection with short-term,noncuffed central venous catheters

BACKGROUND: Noncuffed, percutaneously inserted central venous catheters (CVCs) are widely used and cause at least 250,000 bloodstream infections (BSIs) in U.S. hospitals each year. We report a prospective study to determine whether inflammation at the insertion site is predictive of CVC-related BSI. METHODS: Percutaneously inserted, noncuffed CVCs inserted into the subclavian, internal jugular, or femoral vein in two randomized trials during 1998-2000 were prospectively studied; most patients were in an intensive care unit. The condition of the insertion site was evaluated daily by research nurses, quantifying pain (0, 1), erythema (0-2), swelling (0, 1), and purulence (0, 1); the lowest possible overall inflammation score was 0 and the highest was 5. CVC-related BSI was confirmed in each case by demonstrating concordance between isolates from the catheter segment and from blood cultures by restriction-fragment DNA subtyping. RESULTS: Among 1,263 CVCs prospectively studied, 333 (26.3%) were colonized at removal; of these, 35 catheters (2.7%) caused BSIs (5.9 per 1000 CVC days). BSIs were caused by coagulase-negative staphylococci (n = 27), enterococci (n = 4), enteric Gram-negative bacilli (n = 3), or (n = 1). Most insertion sites showed little or no inflammation at the time of removal. There were no significant differences among mean scores for each inflammatory variable examined or overall score among colonized CVCs (0.1 +/- 0.1), catheters causing CVC-related BSI (0.2 +/- 0.4), and noncolonized CVCs (0.1 +/- 0.1). The sensitivity of local inflammation for diagnosis of CVC-related BSI was dismal (0-3%). CONCLUSION: Local inflammation is uncommon with infected CVCs, probably because most catheter-associated infections are currently caused by coagulase-negative staphylococci, a pathogen that incites little local or systemic inflammation. Whereas overt inflammation of the insertion site should raise suspicion of CVC-related BSI caused by or Gram-negative bacilli, especially if the patient has fever or other signs of sepsis, in general, site appearance cannot be relied on to identify catheter colonization or CVC-related BSI.     

Prevention of Transmission of Multidrug-Resistant Organisms during Catheter Exchange using Antimicrobial Catheters

Exchanging a central venous catheter (CVC) over a guide wire for a fresh uncoated CVC in the presence of bacteremia can result in cross-infection of the newly exchanged CVC. A recent retrospective clinical study showed that exchanging a catheter over a guide wire in the presence of bacteremia using an antimicrobial minocycline-rifampin (M/R) catheter may improve outcomes. To expand on this, we developed an in vitro cross-contamination model of exchange to evaluate the efficacy of different antimicrobial CVCs in preventing cross-contamination of multidrug-resistant organisms during exchange. Uncoated CVCs were allowed to form biofilm by methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. After 24 h, the biofilm-colonized CVCs were placed in a glass tube containing bovine calf serum plus Mueller-Hinton broth, and each catheter was exchanged over a guide wire for a fresh uncoated or an M/R-, chlorhexidine-silver sulfadiazine (CHX/SS)-, or chlorhexidine-M/R (CHX-M/R)-coated CVC. Cross-contamination of exchanged catheters was enumerated by sonication and quantitative plating methods. The exchange of M/R CVCs completely prevented cross-contamination by MRSA biofilms compared to control exchanged CVCs (P < 0.0001). Exchange with CHX/SS CVCs reduced but did not completely prevent cross-contamination by MRSA (P = 0.005). Exchange with CHX-M/R CVCs completely prevented cross-contamination by MRSA, P. aeruginosa, and C. albicans biofilms (P < 0.0001). Furthermore, CHX-M/R CVCs were superior to M/R CVCs against P. aeruginosa and C. albicans (P = 0.003) and were superior to CHX/SS CVCs against MRSA and P. aeruginosa (P = 0.01). In conclusion, exchange with the novel CHX-M/R CVC was the only exchange effective in completely and concurrently preventing cross-contamination from bacteria and Candida.     

Infection control issues in central venous catheter care.

Central venous catheters (CVCs) are now a routine part of patient management in the intensive care unit (ICU). Over time, a vast amount of literature associated with the use and care of CVCs has accumulated. The purpose of this article is to discuss the literature associated with the care of these devices in a narrative format. Although particular attention is paid to infection control issues, other fundamental areas such as catheter design, dressings, line changing and post insertion management are also discussed. The article goes on to look at the future of CVC design and concludes with an analysis of future developments related to CVCs.     

Partial occlusion of indwelling central venous catheters

Partial occlusion of indwelling central venous catheters (CVCs) developed as a clinical problem following the trend to leave CVCs in place for the duration of intravenous therapy, which can last for more than 1 year in some cases. The primary manifestation of partial catheter occlusion is the ability to infuse but not aspirate fluids through an indwelling CVC. There is evidence that the problem is at least partially related to a residue of blood products deposited within some CVCs and implanted ports each time blood is aspirated or infused. Over time, these deposits may act as a ball valve when aspiration from the CVC is attempted while still allowing fluid or drug infusions. A preliminary investigation has indicated that this partial occlusion can be corrected by the use of a fibrinolytic drug to "cleanse" the CVC of residual blood products through lysis, thus restoring full CVC patency. Controlled studies are still needed to determine how often the CVC should be cleansed to prevent buildup of blood products in the indwelling CVC.     

A prospective,longitudinal study of central venous catheter‐related deep venous thrombosis in boys with hemophilia

Summary. Background: Central venous catheters (CVCs) are often inserted into boys with hemophilia to secure venous access for factor prophylaxis and immune tolerance induction therapy. Complications associated with CVCs include catheter‐related infections, local hemorrhage, and mechanical failure. Less frequently reported is CVC‐related deep venous thrombosis (DVT). We conducted a prospective study to determine the frequency and outcome of this complication. Methods: All boys (n = 16) with congenital hemophilia A or B with a CVC in place who were registered in the pediatric comprehensive care program at the Hospital for Sick Children, Toronto, were included in the study. They were prospectively assessed by imaging studies and clinical examinations for CVC‐related DVT at two time‐points, 2 years apart. Each boy was evaluated for inherited hypercoagulability. Results: Eleven (69%) of the 16 boys had radiological evidence of DVT at the first evaluation and 13/16 (81%) at the second evaluation. In two boys there was improvement in the venogram findings at the second evaluation. None of the CVC‐related DVTs completely resolved. Median age at the time of initial insertion of a CVC was 1.0 years (range 0.02–6.7 years). Median duration of CVC placement was 6.4 years (range 3.3–15.5 years). Only 4/13 boys with DVTs had clinical evidence of upper venous system obstruction. Only one boy, who did not develop a DVT, had a low protein C level. Conclusions: CVC‐related DVTs occur in the majority of boys with hemophilia who have CVCs inserted for a prolonged period of time. Annual screening with imaging is recommended for boys with CVCs in place for ≥ 3 years. Consideration should be given to removing CVCs as soon as peripheral venous access is feasible.