Prophylactic urokinase in the management of long-term venous access devices in children: a Children's Oncology Group study

Proteases, a powerful biochemical tool in the service of medicine, clinical and pharmaceutical

Proteases, enzymes that hydrolyze peptide bonds, have various applications in medicine, clinical applications, and pharmaceutical development. They are used in cancer treatment, wound debridement, contact lens cleaning, prion degradation, biofilm removal, and fibrinolytic agents. Proteases are also crucial in cardiovascular disease treatment, emphasizing the need for safe, affordable, and effective fibrinolytic drugs. Proteolytic enzymes and protease biosensors are increasingly used in diagnostic and therapeutic applications. Advanced technologies, such as nanomaterials-based sensors, are being developed to enhance the sensitivity, specificity, and versatility of protease biosensors. These biosensors are becoming effective tools for disease detection due to their precision and rapidity. They can detect extracellular and intracellular proteases, as well as fluorescence-based methods for real-time and label-free detection of virus-related proteases. The active utilization of proteolytic enzymatic biosensors is expected to expand significantly in biomedical research, in-vitro model systems, and drug development. We focused on journal articles and books published in English between 1982 and 2024 for this study.

Iatrogenic vascular trauma and complications of vascular access in children

Vascular access is frequently a critical component of the diagnostic and therapeutic procedures required to manage childhood illnesses, including many emergent conditions and critical illnesses. Vascular access in the pediatric population presents unique challenges, and many clinical and technical factors must be considered to avoid complications that can occur with vascular access procedures. This article reviews various aspects of vascular access and associated iatrogenic trauma in children, including risk factors, management of complications, and preventive measures to avoid complications. It is only with a comprehensive understanding of the topic that vascular access in children can be performed safely, effectively, and efficiently.

The risk of bloodstream infection associated with totally implantable venous access ports in cancer patient: a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to provide evidence-based guidance to better understand the risk of central line-associated bloodstream infection (CLABSI) in cancer patients who received totally implantable venous access ports (TIVAPs) compared with those who received external central venous catheters (CVCs).

METHODS

A systematic search of PubMed, Web of science, Embase, and the Cochrane Library was carried out from inception through Oct 2018, with no language restrictions. Trials examining the risk of CLABSI in cancer patients who received TIVAPs compared with those who received external CVCs were included. Two reviewers independently reviewed, extracted data, and assessed the risk of bias of each study. A random-effect model was used to estimate relative risks (RRs) with 95% CIs.

RESULTS

In all, 26 studies involving 27 cohorts and 5575 patients reporting the incidence of CLABSI in patients with TIVAPs compared with external CVCs were included. Pooled meta-analysis of these trials revealed that TIVAPs were associated with a significant lower risk of CLABSI than were external CVCs (relative risk [RR], 0.44; 95% confidence interval [CI], 0.31-0.62; P < 0.00001), which was confirmed by trial sequential analysis for the cumulative z curve entered the futility area. Subgroup analyses demonstrated that CLABSI reduction was greatest in adult patients (RR [95% CI], 0.35 [0.22-0.56]) compared with pediatric patients who received TIVAPs (RR [95% CI], 0.55 [0.38-0.79]).

CONCLUSIONS

TIVAP can significantly reduce the risk of CLABSI compared with external CVCs.

Central Venous Access Devices (CVAD) in Pediatric Oncology Patients-A Single-Center Retrospective Study Over More Than 9 Years

Background: Central venous access devices (CVAD) provide important benefits in the management of oncological pediatric patients. However, these catheters are responsible for severe complications. Methods: In this context, we aimed to analyze all patients receiving a CVAD in the Department of Pediatric Hematology and Oncology of the University hospital of Mainz over a period of 9 years, focused on CVAD related complications. Data on demographics, as well as intraoperative and postoperative complications were extracted. Results: A total of 296 patients with a mean age 93.2 ± 62.4 months were analyzed. The majority suffered from leukemia (n = 91, 30.7%), lymphomas (n = 50, 16.9%), and brain tumors (n = 48, 16.2%). In 63 (21.3) patients, complications were observed. No death caused by complications of CVADs was found in our series. Catheter-related blood stream infections (BSI) (7.4%) were most prevalent, followed by dislodgements (5.4%), occlusions (2.7%), thrombosis (2.4%), and catheter leakage (2.4%). Insertion site infections were observed in three patients (1.0%). Fifty-nine percent of all patients with catheter-related BSI suffered from Leukemia. In patients with Catheter-related BSIs we detected the condition leukemia as the underlying disease as a risk factor compared to solid tumors as the underlying disease. Overall, totally implanted devices (ports) have a lower complication rate than tunneled catheter. Conclusion: Implantation of CVADs seems to be safe and reliable in this large pediatric patient cohort. Even if complications occur in the long-term management of CVADs, they can be treated successfully and long-term catheter survival rates are excellent.

Long-Term Management of Vascular Access Ports in Nonhuman Primates Used in Preclinical Efficacy and Tolerability Studies

Vascular access ports (VAPs) are an essential tool for long-term vascular access in preclinical studies and disease modeling in non-human primates (NHPs). We retrospectively reviewed central (inferior vena cava, IVC) and portal VAP implantation with the maintenance at our center from 15 January 2010 to 31 January 2018. In total, 209 VAPs were implanted for long-term drug administration and sampling. Patency was >95% at 6 months and >80% at 1 year for IVC VAPs and >90% at 6 months and >85% at 1 year for portal VAPs. The majority of animals had no complications and access was generally durable with device use ranging up to 7 years. In IVC, VAPs loss of patency occurred in 13% (0.035/100 d), surgical site infection in 2.9% (0.097/100 d), port pocket infection in 2.2% (0.004/100 d), erosion in 2.9%, 0.008/100 d), and mechanical failure in 4.3% (0.012/100 d). In portal, VAPs loss of patency occurred in 11.3% (0.028/100 d) and port pocket infection in 1.4% (0.003/100 d). About 12% of VAPs were removed as a result of complications.This study confirms VAP implant and maintenance is a beneficial and safe practice in NHPs resulting in favorable outcomes. High patency rates and low complication rates are comparable to the clinical setting. In addition to enabling comprehensive data collection, VAPs increase satisfaction and well-being by minimizing interference with daily routines and fostering cooperation. VAP implantation, together with an effective maintenance regimen and co-operative handling, is a reliable and convenient refined method for drug administration and blood sampling.Keywords: Vascular access port; nonhuman primates; refinement; central vascular access; portal vascular access; surgical technique; experimental surgery; animal model.

Anticoagulation for people with cancer and central venous catheters

BACKGROUND

Central venous catheter (CVC) placement increases the risk of thrombosis in people with cancer. Thrombosis often necessitates the removal of the CVC, resulting in treatment delays and thrombosis-related morbidity and mortality. This is an update of the Cochrane Review published in 2014.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulation for thromboprophylaxis in people with cancer with a CVC.

SEARCH METHODS

We conducted a comprehensive literature search in May 2018 that included a major electronic search of Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), and Embase (Ovid); handsearching of conference proceedings; checking of references of included studies; searching for ongoing studies; and using the 'related citation' feature in PubMed. This update of the systematic review was based on the findings of a literature search conducted on 14 May 2018.

SELECTION CRITERIA

Randomized controlled trials (RCTs) assessing the benefits and harms of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), vitamin K antagonists (VKA), or fondaparinux or comparing the effects of two of these anticoagulants in people with cancer and a CVC.

DATA COLLECTION AND ANALYSIS

Using a standardized form, we extracted data and assessed risk of bias. Outcomes included all-cause mortality, symptomatic catheter-related venous thromboembolism (VTE), pulmonary embolism (PE), major bleeding, minor bleeding, catheter-related infection, thrombocytopenia, and health-related quality of life (HRQoL). We assessed the certainty of evidence for each outcome using the GRADE approach (Balshem 2011).

MAIN RESULTS

Thirteen RCTs (23 papers) fulfilled the inclusion criteria. These trials enrolled 3420 participants. Seven RCTs compared LMWH to no LMWH (six in adults and one in children), six RCTs compared VKA to no VKA (five in adults and one in children), and three RCTs compared LMWH to VKA in adults.LMWH versus no LMWHSix RCTs (1537 participants) compared LMWH to no LMWH in adults. The meta-analyses showed that LMWH probably decreased the incidence of symptomatic catheter-related VTE up to three months of follow-up compared to no LMWH (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.22 to 0.81; risk difference (RD) 38 fewer per 1000, 95% CI 13 fewer to 52 fewer; moderate-certainty evidence). However, the analysis did not confirm or exclude a beneficial or detrimental effect of LMWH on mortality at three months of follow-up (RR 0.82, 95% CI 0.53 to 1.26; RD 14 fewer per 1000, 95% CI 36 fewer to 20 more; low-certainty evidence), major bleeding (RR 1.49, 95% CI 0.06 to 36.28; RD 0 more per 1000, 95% CI 1 fewer to 35 more; very low-certainty evidence), minor bleeding (RR 1.35, 95% CI 0.62 to 2.92; RD 14 more per 1000, 95% CI 16 fewer to 79 more; low-certainty evidence), and thrombocytopenia (RR 1.03, 95% CI 0.80 to 1.33; RD 5 more per 1000, 95% CI 35 fewer to 58 more; low-certainty evidence).VKA versus no VKAFive RCTs (1599 participants) compared low-dose VKA to no VKA in adults. The meta-analyses did not confirm or exclude a beneficial or detrimental effect of low-dose VKA compared to no VKA on mortality (RR 0.99, 95% CI 0.64 to 1.55; RD 1 fewer per 1000, 95% CI 34 fewer to 52 more; low-certainty evidence), symptomatic catheter-related VTE (RR 0.61, 95% CI 0.23 to 1.64; RD 31 fewer per 1000, 95% CI 62 fewer to 51 more; low-certainty evidence), major bleeding (RR 7.14, 95% CI 0.88 to 57.78; RD 12 more per 1000, 95% CI 0 fewer to 110 more; low-certainty evidence), minor bleeding (RR 0.69, 95% CI 0.38 to 1.26; RD 15 fewer per 1000, 95% CI 30 fewer to 13 more; low-certainty evidence), premature catheter removal (RR 0.82, 95% CI 0.30 to 2.24; RD 29 fewer per 1000, 95% CI 114 fewer to 202 more; low-certainty evidence), and catheter-related infection (RR 1.17, 95% CI 0.74 to 1.85; RD 71 more per 1000, 95% CI 109 fewer to 356; low-certainty evidence).LMWH versus VKAThree RCTs (641 participants) compared LMWH to VKA in adults. The available evidence did not confirm or exclude a beneficial or detrimental effect of LMWH relative to VKA on mortality (RR 0.94, 95% CI 0.56 to 1.59; RD 6 fewer per 1000, 95% CI 41 fewer to 56 more; low-certainty evidence), symptomatic catheter-related VTE (RR 1.83, 95% CI 0.44 to 7.61; RD 15 more per 1000, 95% CI 10 fewer to 122 more; very low-certainty evidence), PE (RR 1.70, 95% CI 0.74 to 3.92; RD 35 more per 1000, 95% CI 13 fewer to 144 more; low-certainty evidence), major bleeding (RR 3.11, 95% CI 0.13 to 73.11; RD 2 more per 1000, 95% CI 1 fewer to 72 more; very low-certainty evidence), or minor bleeding (RR 0.95, 95% CI 0.20 to 4.61; RD 1 fewer per 1000, 95% CI 21 fewer to 95 more; very low-certainty evidence). The meta-analyses showed that LMWH probably increased the risk of thrombocytopenia compared to VKA at three months of follow-up (RR 1.69, 95% CI 1.20 to 2.39; RD 149 more per 1000, 95% CI 43 fewer to 300 more; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence was not conclusive for the effect of LMWH on mortality, the effect of VKA on mortality and catheter-related VTE, and the effect of LMWH compared to VKA on mortality and catheter-related VTE. We found moderate-certainty evidence that LMWH reduces catheter-related VTE compared to no LMWH. People with cancer with CVCs considering anticoagulation should balance the possible benefit of reduced thromboembolic complications with the possible harms and burden of anticoagulants.

Prophylactic rtPA in the Prevention of Line-associated Thrombosis and Infection in Short Bowel Syndrome

BACKGROUND

Central venous access devices (CVADs) are essential for total parenteral nutrition administration in patients with short bowel syndrome (SBS). They are, however, fraught with complications including infection and venous thromboembolism (VTE), which increases associated morbidity and mortality in this population. There is evidence linking the development of CVAD-associated thrombosis and line-related infection. Thus, it has been postulated that prevention of catheter-related clot formation could minimize the risk of infection originating from the catheter. Recombinant tissue plasminogen activator (rtPA, alteplase), lyses clots by binding plasmin-bound fibrin in a clot and cleaving plasminogen to plasmin; moreover, it is widely used to clear occluded CVADs.

METHODS

Prophylactic rtPA lock therapy in children with SBS was evaluated as a single site pilot study to minimize line-associated VTE, infection, need for line replacement, and hospitalization at the Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center. rtPA lock therapy was administered by parents/caregivers on a weekly basis over a 6-month time period in place of heparin lock therapy. Comparisons were made between line-associated complications in the cohort in the 6 months before study versus during the study period.

RESULTS

Six out of 8 subjects completed the study over a 1-year time period. As a group, subjects experienced a significant decrease in the number of line-associated bloodstream infections from a mean of 1.9 infections in the 6 months before the study to a mean of 0.5 infections (P = 0.025). There was no change in the need for line replacement amongst subjects while on study. The primary outcome of VTE was not found in the cohort, and it is unclear whether rtPA lock therapy contributed to the lack of thrombosis development. Given the success of rtPA in this pilot study in reducing bloodstream infections, further investigation or rtPA lock therapy in patients with SBS is warranted.

Urokinase Lock or Flush Solution for Prevention of Bloodstream Infections Associated with Central Venous Catheters for Chemotherapy: A Meta-Analysis of Prospective Randomized Trials

Background

Intravascular devices (IVDs) carry significant risk of device-associated bloodstream infection (BSI). Catheter thrombosis increases the likelihood of microbial colonization of the catheter and BSI. Urokinase has been studied for the prevention of BSI associated with IVDs. We undertook a systematic review to determine the efficacy of urokinase-heparin lock or flush solution compared with heparin alone in preventing IVD-associated BSI.

Methods

Computerized databases were searched for relevant publications in English from January 1966 to 1 January 2007. We identified randomized controlled trials comparing a urokinase-heparin lock or flush solution with heparin alone for prevention of BSI associated with long-term IVDs. Summary effect sizes were calculated with assessment of heterogeneity.

Results

Five randomized, controlled trials involving a total of 991 patients being treated with IVDs met the inclusion criteria; all five studies were conducted among patients with cancer; three of these studies were undertaken in children and two in adults. The summary risk ratio with a urokinase-heparin lock solution for IVD-associated BSI was 0.77 (95% confidence interval [CI], 0.60–0.98; p=0.01). Results of the test for heterogeneity were not statistically significant (p=0.53).

Conclusions

Use of a urokinase lock solution in high-risk patient populations being treated with long-term central IVDs may reduce the risk of BSI. However, there are few randomized trials and methodologic limitations of these preclude more robust recommendations regarding the use of urokinase to prevent BSI. Further adequately powered studies should seek to evaluate the efficacy of urokinase and optimize dosage and instillation regimen.

Venous Ports in Infants

PURPOSE

To evaluate technical success and the incidences of, and risk factors for, mechanical and infectious complications of venous port placement in infants.

MATERIALS AND METHODS

This was a retrospective single-institution cohort study of port placement in infants (age < 1 y) from January 2006 through June 2016 (mean age, 7.5 mo ± 3.3; mean weight, 8.1 kg ± 1.9). Age, weight, sex, side of placement, tip position, and indication for placement (chemotherapy vs other) were recorded. Total catheter-days (CDs), mechanical complications, and central catheter-associated bloodstream infections (CCABSIs) were identified.

RESULTS

During the study years, 64 ports were placed in 64 infants, with a technical success rate of 100%. The mean catheter life was 321 days (total range, 4-1,917 d; interquartile range [IQR], 107-421 d). There were 13 CCABSI events (0.63 per 1,000 CDs); of these, 8 (12.5% among 64 patients) required port removal for infection. There was an increase in CCABSIs in patients with left-sided port placement (relative risk [RR], 3.22; 95% confidence interval [CI], 1.02-10.14; P = .05). There were 8 mechanical complications of the port reservoir or catheter (0.39 per 1,000 CDs). Of these, 2 (3.1%) required removal. Patients in the lowest weight quartile were at an increased risk of mechanical complications (RR, 4.37; 95% CI, 1.09-17.48; P = .04).

CONCLUSIONS

Venous ports can be placed with a high rate of technical success in infants. Left-sided ports and low weight are associated with increased infectious and mechanical complications, respectively.

Twenty-five Years of Advances in Vascular Access: Bridging Research to Clinical Practice

Vascular access has become a key component for a multitude of IV therapies, including parenteral nutrition. Access of the central venous system has been long recognized for its associated complications of infection, thrombosis, and occlusion. Over the past 25 years, clinical practice based on research and innovation has attempted to decrease complication rates and therefore improve the safety of vascular access. This article highlights the research and its influence on catheter care procedures, technology, and education that has led to advances in vascular access. An improved understanding of the pathophysiology associated with catheter-related complications and an ongoing evaluation of new treatment modalities has provided clinicians today with new options for improved patient care and the ability to preserve vascular access options for patients.

Hickman catheter and implantable port devices for the delivery of chemotherapy: a phase II randomised controlled trial and economic evaluation

BACKGROUND

In the United Kingdom, totally implantable venous access systems (TIVAS) are not routinely used. Compared with Hickman catheters, these devices are more expensive and complex to insert. However, it is unclear whether the higher costs may be offset by perceived greater health benefits. This pilot trial aimed to generate relevant data to inform the design of a larger definitive randomised controlled trial.

METHODS

This was a phase II prospective, randomised, open trial from two UK oncology centres. The primary end point was overall complication rate. Secondary end points included individual complication rates, time to first complication and quality of life. Analysis was by intention to treat. An economic evaluation was also carried out.

RESULTS

A total of 100 patients were randomised in a 3 : 1 ratio to receive a Hickman or a TIVAS. Overall, 54% of patients in the Hickman arm suffered one or more complications compared with 38% in the TIVAS arm (one-sided P=0.068). In the Hickman arm, 28% of the devices were removed prematurely due to a complication compared with 4% in the TIVAS arm. Quality of life based on the device-specific questionnaire was greater in the TIVAS arm for 13 of the 16 questions. The economic evaluation showed that Hickman arm was associated with greater mean cost per patient £1803 (95% CI 462, 3215), but similar quality-adjusted life years -0.01 (95% CI -0.15, 0.15) than the TIVAS arm. However, there is much uncertainty associated with the results.

CONCLUSIONS

Compared with Hickman catheters, TIVAS may be the cost-effective option. A larger multicentre trial is needed to confirm these preliminary findings.

Evidence-Based Criteria for the Choice and the Clinical use of the Most Appropriate Lock Solutions for Central Venous Catheters (Excluding Dialysis Catheters): A GAVeCeLT Consensus

Background

The most appropriate lock solution for central venous access devices is still to be defined. GAVeCeLT – the Italian group for venous access devices – has developed a consensus on the evidence-based criteria for the choice and the clinical use of the most appropriate lock solution for central venous catheters (excluding dialysis catheters).

Method

After the constitution of a panel of experts, a systematic collection and review of the literature has been performed, focusing on clinical studies dealing with lock solutions used for prevention of occlusion (heparin, citrate, urokinase, recombinant tissue plasminogen activator [r-TPA], normal saline) or for prevention of infection (citrate, ethanol, taurolidine, ethylene-diamine-tetra-acetic acid [EDTA], vancomycin, linezolid and other antibiotics), in both adults and in pediatric patients. Studies on central lines used for dialysis or pheresis, on peripheral venous lines and on arterial lines were excluded from this analysis. Studies on lock solutions used for treatment of obstruction or infection were not considered. The consensus has been carried out according to the Delphi method.

Results

The panel has concluded that: (a) there is no evidence supporting the heparin lock; (b) the prevention of occlusion is based on the proper flushing and locking technique with normal saline; (c) the most appropriate lock solution for infection prevention should include citrate and/or taurolidine, which have both anti-bacterial and anti-biofilm activity, with negligible undesired effects if compared to antibiotics; (d) the patient populations most likely to benefit from citrate/taurolidine lock are yet to be defined.

Conclusions

The actual value of heparinization for non-dialysis catheters should be reconsidered. Also, the use of lock with substances with anti-bacterial and anti-biofilm activity (such as citrate or taurolidine) should be taken into consideration in selected populations of patients.

Catheter-Related Complications in Children With Cancer Receiving Parenteral Nutrition: Change in Risk Is Moderated by Catheter Type

BACKGROUND

Although central venous catheters (CVCs) are essential to pediatric cancer care, complications are common (eg, occlusion, central line-associated bloodstream infection [CLABSI]). Parenteral nutrition (PN) and external CVCs are associated with an increased complication risk, but their interaction is unknown.

METHODS

A retrospective matched cohort study of pediatric oncology patients who received PN through subcutaneous ports or external CVCs. Complication rates were compared between CVC types during PN and non-PN periods (log-negative binomial model).

RESULTS

Risk of CLABSI was higher during PN for children with ports (relative risk [RR] = 39.6; 95% confidence interval, 5.0-309) or external CVCs (RR = 2.9; 95% confidence interval, 1.1-7.4). This increased risk during PN was greater for ports than for external CVCs (ratio of relative risks = 13.6). Occlusion risk was higher during PN in both groups (RR = 10.0 for ports; RR = 2.0 for external CVCs), and the increase was significantly greater in ports (ratio of relative risks, 4.9). Overall, complication rates for ports were much lower than for external CVCs during the non-PN period but similar during the PN period.

CONCLUSION

Children with cancer who receive PN have increased risk of CLABSI and occlusion. The risk increase is greatest in children with ports: a 40- and 10-fold increase in infection risk and occlusion, respectively, resulting in similar complication rates during PN regardless of CVC type and negating the usual benefits of ports. Children with cancer who will require PN should have primary insertion of external CVCs where possible.

Monitoring Central Venous Catheter Resistance to Predict Imminent Occlusion: A Prospective Pilot Study

BACKGROUND

Long-term central venous catheters are essential for the management of chronic medical conditions, including childhood cancer. Catheter occlusion is associated with an increased risk of subsequent complications, including bloodstream infection, venous thrombosis, and catheter fracture. Therefore, predicting and pre-emptively treating occlusions should prevent complications, but no method for predicting such occlusions has been developed.

METHODS

We conducted a prospective trial to determine the feasibility, acceptability, and efficacy of catheter-resistance monitoring, a novel approach to predicting central venous catheter occlusion in pediatric patients. Participants who had tunneled catheters and were receiving treatment for cancer or undergoing hematopoietic stem cell transplantation underwent weekly catheter-resistance monitoring for up to 12 weeks. Resistance was assessed by measuring the inline pressure at multiple flow-rates via a syringe pump system fitted with a pressure-sensing transducer. When turbulent flow through the device was evident, resistance was not estimated, and the result was noted as "non-laminar."

RESULTS

Ten patients attended 113 catheter-resistance monitoring visits. Elevated catheter resistance (>8.8% increase) was strongly associated with the subsequent development of acute catheter occlusion within 10 days (odds ratio = 6.2; 95% confidence interval, 1.8-21.5; p <0.01; sensitivity, 75%; specificity, 67%). A combined prediction model comprising either change in resistance greater than 8.8% or a non-laminar result predicted subsequent occlusion (odds ratio = 6.8; 95% confidence interval, 2.0-22.8; p = 0.002; sensitivity, 80%; specificity, 63%). Participants rated catheter-resistance monitoring as highly acceptable.

CONCLUSIONS

In this pediatric hematology and oncology population, catheter-resistance monitoring is feasible, acceptable, and predicts imminent catheter occlusion. Larger studies are required to validate these findings, assess the predictive value for other clinical outcomes, and determine the impact of pre-emptive therapy.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01737554.

Flushing and Locking of Venous Catheters: Available Evidence and Evidence Deficit

Flushing and locking of intravenous catheters are thought to be essential in the prevention of occlusion. The clinical sign of an occlusion is catheter malfunction and flushing is strongly recommended to ensure a well-functioning catheter. Therefore fluid dynamics, flushing techniques, and sufficient flushing volumes are important matters in adequate flushing in all catheter types. If a catheter is not in use, it is locked. For years, it has been thought that the catheter has to be filled with an anticoagulant to prevent catheter occlusion. Heparin has played a key role in locking venous catheters. However, the high number of risks associated with heparin forces us to look for alternatives. A long time ago, 0.9% sodium chloride was already introduced as locking solution in peripheral cannulas. More recently, a 0.9% sodium chloride lock has also been investigated in other types of catheters. Thrombolytic agents have also been studied as a locking solution because their antithrombotic effect was suggested as superior to heparin. Other catheter lock solutions focus on the anti-infective properties of the locks such as antibiotics and chelating agents. Still, the most effective locking solution will depend on the catheter type and the patient's condition.

Anticoagulation for people with cancer and central venous catheters

BACKGROUND

Central venous catheter (CVC) placement increases the risk of thrombosis in people with cancer. Thrombosis often necessitates the removal of the CVC, resulting in treatment delays and thrombosis-related morbidity and mortality.

OBJECTIVES

To evaluate the relative efficacy and safety of anticoagulation for thromboprophylaxis in people with cancer with a CVC.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 12, 2012), MEDLINE Ovid (January 1966 to February 2013), and EMBASE Ovid (1980 to February 2013). We handsearched conference proceedings, checked references of included studies, used the 'related citations' feature within PubMed, and searched clinicaltrials.gov for ongoing studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing the effects of any dose of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), vitamin K antagonists (VKA), or fondaparinux with no intervention or placebo or comparing the effects of two different anticoagulants in people with cancer and a CVC.

DATA COLLECTION AND ANALYSIS

Teams of two review authors independently used a standardized form to extract data in duplicate. They resolved any disagreements by discussion. They extracted data on risk of bias, participants, interventions, and outcomes. Outcomes of interest included mortality, symptomatic deep venous thrombosis (DVT), asymptomatic DVT, major bleeding, minor bleeding, infection, and thrombocytopenia. Where possible, we conducted meta-analyses using the random-effects model.

MAIN RESULTS

Of 9559 identified citations, we included 12 RCTs (17 publications) reporting follow-up data on 2823 participants. Two of the RCTs included children. Of the 10 RCTs including 2564 adults, one compared prophylactic dose heparin with low-dose VKA. Three RCTs compared VKA with no VKA and four RCTs compared heparin with no heparin. Two additional trials had three separate arms comparing heparin, VKA, and no intervention. Prophylactic-dose heparin, compared with no heparin, was associated with a statistically significant reduction in symptomatic DVT (risk ratio (RR) 0.48; 95% confidence interval (CI) 0.27 to 0.86; moderate-quality evidence). However, results did not confirm or exclude a beneficial or detrimental effect of heparin on mortality (RR 0.82; 95% CI 0.53 to 1.26; moderate-quality evidence), major bleeding (RR 0.49; 95% CI 0.03 to 7.84; low-quality evidence), infection (RR 1.00; 95% CI 0.54 to 1.85; moderate-quality evidence); thrombocytopenia (RR 1.03; 95% CI 0.80 to 1.33; moderate-quality evidence), or minor bleeding (RR 1.35; 95% CI: 0.62 to 2.92). Low-dose VKAs, compared with no VKAs, were associated with a statistically significant reduction in asymptomatic DVT (RR 0.43; 95% CI 0.30 to 0.62). Results did not confirm or exclude a beneficial or detrimental effect of VKAs on mortality (RR 1.04; 95% CI 0.89 to 1.22; low-quality evidence), symptomatic DVT (RR 0.51; 95% CI 0.21 to 1.22; low-quality evidence), major bleeding (RR 7.60; 95% CI 0.94 to 61.49; very-low-quality evidence), or minor bleeding (RR 3.14; 95% CI 0.14 to 71.51). The use of heparin, compared with VKA was associated with a statistically significant increase in thrombocytopenia (RR 3.73; 95% CI 2.26 to 6.16; low-quality evidence) and asymptomatic DVT (RR 1.74; 95% CI 1.20 to 2.52). However, results did not show or exclude a beneficial or detrimental effect on any of the other outcomes of interest (very-low-quality evidence).

AUTHORS' CONCLUSIONS

Compared with no anticoagulation, we found a statistically significant reduction of symptomatic DVT with heparin and asymptomatic DVT with VKA. Heparin was associated with a higher risk of thrombocytopenia and asymptomatic DVT when compared with VKA. However, the findings did not rule out other clinically important benefits and harms. People with cancer with CVCs considering anticoagulation should balance the possible benefit of reduced thromboembolic complications with the possible harms and burden of anticoagulants.

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

BACKGROUND

Heparin intermittent flushing is a standard practice in the maintenance of patency in central venous catheters. However, we could find no systematic review examining its effectiveness and safety.

OBJECTIVES

To assess the effectiveness of intermittent flushing with heparin versus 0.9% sodium chloride (normal saline) solution in adults with central venous catheters in terms of prevention of occlusion and overall benefits versus harms.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched December 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11). Searches were also carried out in MEDLINE, EMBASE, CINAHL and clinical trials databases (December 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) in adults 18 years of age and older with a central venous catheter (CVC) in which intermittent flushing with heparin (any dose with or without other drugs) was compared with 0.9% normal saline were included. No restriction on language was applied.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality and extracted data. Trial authors were contacted to retrieve additional information, when necessary.

MAIN RESULTS

Six eligible studies with a total of 1433 participants were included. The heparin concentrations used in these studies were very different (10-5000 IU/mL), and follow-up varied from 20 days to 180 days. The overall risk of bias in the studies was low. The quality of the evidence ranged from very low to moderate for the main outcomes (occlusion of CVC, duration of catheter patency, CVC-related sepsis, mortality and haemorrhage at any site).Combined findings from three trials in which the unit of analysis was the catheter suggest that heparin was associated with reduced CVC occlusion rates (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.29 to 0.94). However, no clear evidence of a similar effect was found when the results of two studies in which the unit of analysis was the participant were combined (RR 0.21, 95% CI 0.03 to 1.70), nor when findings were derived from one study, which considered total line accesses (RR 1.08, 95% CI 0.84 to 1.40). Furthermore, results for other estimated effects were found to be imprecise and compatible with benefit and harm: catheter duration in days (mean difference (MD) 0.41, 95% CI -1.29 to 2.12), CVC-related thrombosis (RR 1.22, 95% CI 0.74 to 1.99), CVC-related sepsis (RR 1.02, 95% CI 0.34 to 3.03), mortality (RR 0.77, 95% CI 0.45 to 1.32) and haemorrhage at any site (RR 1.37, 95% CI 0.49 to 3.85).

AUTHORS' CONCLUSIONS

We found no conclusive evidence of important differences when heparin intermittent flushing was compared with 0.9% normal saline flushing for central venous catheter maintenance in terms of efficacy or safety. As heparin is more expensive than normal saline, our findings challenge its continued use in CVC flushing outside the context of clinical trials.

Comparison of hospital length of stay, costs, and readmissions of alteplase versus catheter replacement among patients with occluded central venous catheters

BACKGROUND

Central venous catheter (CVC) occlusion is common, affecting 30% of all CVCs.

OBJECTIVE

To compare length of stay (LOS), costs, and readmissions associated with the use of alteplase to clear catheter blockage to outcomes associated with catheter replacement.

DESIGN

Retrospective observational study utilizing a large hospital database.

PARTICIPANTS

Hospitalized patients treated for catheter occlusion from January 2006 to December 2011.

MAIN MEASURES

Univariate analyses of patient characteristics and treatment patterns and multivariable regression analyses of postocclusion hospital costs, LOS, and 30- and 90-day readmissions were conducted.

KEY RESULTS

We included 34,579 patients treated for a CVC occlusion by replacement (N=1028) or by alteplase (2 mg) administration (N=33,551). Patients receiving alteplase were somewhat younger than those having catheter replacement (60 ± 19 vs 62 ± 20 years old, P=0.0002). After adjusting for patient and hospital factors via regression modeling, average daily postocclusion costs were $317 lower for alteplase recipients than for catheter replacement patients (95% confidence interval [CI]: 238.22-392.24; P<0.0001). Adjusted total postocclusion costs were $1419 lower for alteplase recipients versus patients receiving catheter replacement (95% CI: 307.27-2458.12; P=0.0121). Postocclusion operating room/surgery, radiology, and supply costs were significantly lower for alteplase recipients (P<0.001). Average adjusted postocclusion LOS was similar for both groups (P>0.05). Odds of readmission were not significantly different at 30 or 90 days.

CONCLUSIONS

Among patients treated for an occluded CVC, alteplase-treated patients had lower daily and total postocclusion costs than patients receiving catheter replacement. Cost differences were mainly driven by lower operating room/surgery, radiology, and supplier costs.

Prevention and treatment of intraluminal catheter thrombosis in children hospitalised in a paediatric intensive care unit

AIM

The aim of the study was to develop and implement a protocol for the prevention and treatment of catheter related intraluminal thrombosis in a paediatric intensive care unit

METHODS

A computerised search was carried out on MEDLINE, through PubMed, using the medical subject heading 'central venous catheter', 'central venous access device', 'central venous line' associated with 'occlusion', 'obstruction', 'catheter-related thrombosis', 'critically ill patients' and 'thrombolytic therapy'. References of reviewed articles were also searched for relevant titles as well as non-randomised controlled trials and series of cases when no information of higher level of evidence was available.

RESULTS

With the information gathered, a protocol for the prevention and treatment of catheter related intraluminal thrombosis was elaborated and those recommendations that best suit our environment were included. They were agreed upon by a broad panel of professionals working in the Pediatric Intensive Care Unit and the Pharmacy Department.

CONCLUSIONS

Due to the variety of options available for the pharmacotherapeutic management of intraluminal catheter thrombosis, one measure to improve the quality of the therapy and to diminish the variability in the prescription could be the implementation of a protocol as described in this paper.

Management of thrombotic complications in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children, and has been reported as the most common malignancy associated with thromboembolism in the pediatric age group. Treatment with Escherichia coli asparaginase, concomitant steroids, presence of central venous lines, and thrombophilic abnormalities are established risk factors for thromboembolism. The incidence varies with age, co-morbidities and chemotherapy regimens but the risk is highest during the induction and intensification phases. Treatment is necessary in majority of children to prevent serious sequelae. Mortality from thromboembolic events in any location is 2 to 4 % and the risk of recurrence is 7 to 10 %, further enhanced in the setting of malignancy. Randomized trials of venous thromboembolism (VTE) management in pediatric patients with ALL are lacking due to the low overall incidence, resulting in considerable variation in practice. The objective of this article is to review current knowledge on the treatment and prevention of thrombosis associated with pediatric ALL.

Systemic treatments for the prevention of venous thrombo-embolic events in paediatric cancer patients with tunnelled central venous catheters

BACKGROUND

Venous thrombo-embolic events (VTEs) occur in 2.2% to 14% of paediatric cancer patients and cause significant morbidity and mortality. The malignant disease itself, the cancer treatment and the presence of central venous catheters (CVCs) increase the risk of VTE.

OBJECTIVES

The primary objective of this review was to investigate the effects of preventive systemic treatments in paediatric cancer patients with tunnelled CVCs on (a)symptomatic VTE. Secondary objectives of this review were to investigate adverse effects of systemic treatments for the prevention of (a)symptomatic VTE in paediatric cancer patients with tunnelled CVCs; and to investigate the effects of systemic treatments in the prevention of (a)symptomatic VTE with CVC-related infection in paediatric cancer patients with tunnelled CVCs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 8 2012), MEDLINE (1966 to August 2012) and EMBASE (1966 to August 2012). In addition, we searched reference lists from relevant articles and conference proceedings of the International Society for Paediatric Oncology (SIOP) (from 2006 to 2011), the American Society of Clinical Oncology (ASCO) (from 2006 to 2011), the American Society of Hematology (ASH) (from 2006 to 2011) and the International Society of Thrombosis and Haematology (ISTH) (from 2006 to 2011). We scanned the International Standard Randomised Controlled Trial Number (ISRCTN) Register and the National Institute of Health (NIH) Register for ongoing trials (www.controlled-trials.com) (August 2012), and we contacted the authors of eligible studies if additional information was required.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing systemic treatments to prevent venous thrombo-embolic events (VTEs) in paediatric cancer patients with tunnelled CVCs with a control intervention or no systemic treatment. For the description of adverse events, cohort studies were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data and performed risk of bias assessment of included studies. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Three RCTs and three CCTs (including 1291 children) investigated the prevention of VTE (low molecular weight heparin (LMWH) n = 134, antithrombin (AT) supplementation n = 37, low-dose warfarin n = 31, cryoprecipitate and/or fresh frozen plasma (FFP) supplementation n = 240, AT supplementation and LMWH n = 41). AT, cryoprecipitate and FFP were supplemented only in cases of AT or fibrinogen deficiency. Of the six included RCTs/CCTs, five investigated the prevention of VTE compared with no intervention (n = 737), and one CCT compared AT supplementation and LMWH with AT supplementation (n = 71). All studies had methodological limitations, and clinical heterogeneity between studies was noted.We found no significant effects of systemic treatments compared with no intervention in preventing (a)symptomatic VTE and no differences in adverse events (such as major and/or minor bleeding; none of the studies reported thrombocytopenia, heparin-induced thrombocytopenia (HIT), heparin-induced thrombocytopenia with thrombosis (HITT), death as a result of VTE, removal of CVC due to VTE, CVC-related infection, and post-thrombotic syndrome (PTS)) between experimental and control groups. Two studies with comparable participant groups and interventions were included for meta-analyses (n = 182). In the experimental group, 1/68 (1.5%) children were diagnosed with symptomatic VTE, as were 4/114 (3.5%) in the control group (best case scenario: risk ratio (RR) 0.65, 95% confidence interval (CI) 0.09 to 4.78). These studies also evaluated asymptomatic CVC-related VTE: In the experimental group, 22/68 (32.4%) were diagnosed with asymptomatic VTE, as were 35/114 (30.7%) in the control group (best case scenario: RR 1.02, 95% CI 0.40 to 2.55). Heterogeneity was substantial for this analysis: I(2) = 73%.The attribution of LMWH to AT supplementation resulted in a significant reduction in symptomatic VTE (Fisher's exact test, two-sided P = 0.028) without bleeding complications; asymptomatic VTE, thrombocytopenia, HIT, HITT, death as a result of VTE, removal of CVC due to VTE, CVC-related infection and PTS were not assessed.Four cohort studies were included for the evaluation of adverse events. Three studies provided information on bleeding episodes: One participant developed an ischaemo-haemorrhagic stroke. One study provided information on other adverse events: None occurred.

AUTHORS' CONCLUSIONS

We found no significant effects of systemic treatments compared with no intervention in preventing (a)symptomatic VTE in paediatric oncology patients with CVCs. However, this could be a result of the low number of included participants, which resulted in low power. In one CCT, which compared one systemic treatment with another systemic treatment, we identified a significant reduction in symptomatic VTE with the addition of LMWH to AT supplementation.All studies investigated the prevalence of major and/or minor bleeding episodes, and none found a significant difference between study groups. None of the studies reported thrombocytopenia, HIT, HITT, death as a result of VTE, removal of CVC due to VTE, CVC-related infection or PTS among participants.On the basis of currently available evidence, we are not able to give recommendations for clinical practise. Additional well-designed international RCTs are needed to further explore the effects of systemic treatments in preventing VTE. Future studies should aim for adequate power with attainable sample sizes. The incidence of symptomatic VTE is relatively low; therefore, it might be necessary to select participants with thrombotic risk factors or to investigate asymptomatic VTE instead.

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.

Antibiotic and other lock treatments for tunnelled central venous catheter-related infections in children with cancer

BACKGROUND

The risk of developing a tunnelled central venous catheter (CVC)-related infection ranges between 0.1 and 2.3 per 1000 catheter days for children with cancer. These infections are difficult to treat with systemic antibiotics (salvage rate 24% - 66%) due to biofilm formation in the CVC. Lock treatments can achieve 100 - 1000 times higher concentrations locally without exposure to high systemic concentrations.

OBJECTIVES

Our objective was to investigate the efficacy of antibiotic and other lock treatments in the treatment of CVC-related infections in children with cancer compared to a control intervention. We also assessed adverse events of lock treatments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, issue 3, 2011), MEDLINE/PubMed (1945 to August 2011) and EMBASE/Ovid (1980 to August 2011). In addition we searched reference lists from relevant articles and the conference proceedings of the International Society for Paediatric Oncology (SIOP) (from 2006 to 2010), American Society of Clinical Oncology (ASCO) (from 2006 to 2010), the Multinational Association of Supportive Care in Cancer (MASCC) (from 2006 to 2011), the American Society of Hematology (ASH) (from 2006 to 2010) and the International Society of Thrombosis and Haematology (ISTH) (from 2006 to 2011). We scanned the ISRCTN Register and the National Institute of Health Register for ongoing trials (www.controlled-trials.com) (August 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing an antibiotic lock or other lock treatment (with or without concomitant systemic antibiotics) with a control intervention (other lock treatment with or without concomitant systemic antibiotics or systemic antibiotics alone) for the treatment of CVC-related infections in children with cancer. For the description of adverse events, cohort studies were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data and performed 'Risk of bias' assessments of included studies. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Two RCTs evaluated urokinase lock treatment with concomitant systemic antibiotics (n = 56) versus systemic antibiotics alone (n = 48), and one CCT evaluated ethanol lock treatment with concomitant systemic antibiotics (n = 15) versus systemic antibiotics alone (n = 13). No RCTs or CCTs evaluating antibiotic lock treatments were identified. All studies had methodological limitations and clinical heterogeneity between studies was present. We found no evidence of significant difference between ethanol or urokinase lock treatments with concomitant systemic antibiotics and systemic antibiotics alone regarding the number of participants cured, the number of recurrent CVC-related infections, the number of days until the first negative blood culture, the number of CVCs prematurely removed, ICU admission and sepsis. Not all studies were included in all analyses. No adverse events occurred in the five publications of cohort studies (one cohort was included in two publications) assessing this outcome; CVC malfunctioning occurred in three out of five publications of cohort studies assessing this outcome.

AUTHORS' CONCLUSIONS

No significant effect of urokinase or ethanol lock in addition to systemic antibiotics was found. However, this could be due to low power or a too-short follow-up. The cohort studies identified no adverse events; some cohort studies reported CVC malfunctioning. No RCTs or CCTs were published on antibiotic lock treatment alone. More well-designed RCTs are needed to further explore the effect of antibiotic or other lock treatments in the treatment of CVC-related infections in children with cancer.

Central venous catheter care for the patient with cancer: American Society of Clinical Oncology clinical practice guideline

PURPOSE

To develop an evidence-based guideline on central venous catheter (CVC) care for patients with cancer that addresses catheter type, insertion site, and placement as well as prophylaxis and management of both catheter-related infection and thrombosis.

METHODS

A systematic search of MEDLINE and the Cochrane Library (1980 to July 2012) identified relevant articles published in English.

RESULTS

The overall quality of the randomized controlled trial evidence was rated as good. There is consistency among meta-analyses and guidelines compiled by other groups as well.

RECOMMENDATIONS

There is insufficient evidence to recommend one CVC type or insertion site; femoral catheterization should be avoided. CVC should be placed by well-trained providers, and the use of a CVC clinical care bundle is recommended. The use of antimicrobial/antiseptic-impregnated and/or heparin-impregnated CVCs is recommended to decrease the risk of catheter-related infections for short-term CVCs, particularly in high-risk groups; more research is needed. The prophylactic use of systemic antibiotics is not recommended before insertion. Data are not sufficient to recommend for or against routine use of antibiotic flush/lock therapy; more research is needed. Before starting antibiotic therapy, cultures should be obtained. Some life-threatening infections require immediate catheter removal, but most can be treated with antimicrobial therapy while the CVC remains in place. Routine flushing with saline is recommended. Prophylactic use of warfarin or low-molecular weight heparin is not recommended, although a tissue plasminogen activator (t-PA) is recommended to restore patency to occluded catheters. CVC removal is recommended when the catheter is no longer needed or if there is a radiologically confirmed thrombosis that worsens despite anticoagulation therapy.

Alteplase use for malfunctioning central venous catheters correlates with catheter-associated bloodstream infections

OBJECTIVES

A catheter thrombosis and the presence of a catheter-associated bloodstream infection (CBSI) often occur simultaneously, but it is unclear if or to what degree the two complications relate. Several animal and adult studies indicate a relationship between fibrin sheaths and thrombi in the development of CBSIs. To date, there has been limited human investigation in the pediatric population to determine a clear link between the presence of a thrombus and bacteremia. The use of alteplase for malfunctioning central venous catheter may indicate the formation of intraluminal thrombus or fibrin sheath. A catheter that requires alteplase is at higher risk of a CBSI.

DESIGN

A retrospective chart review from July 2008 to December 2010.

SETTING

PICU.

PATIENTS

All patients with central catheters admitted to the PICU.

INTERVENTIONS

No interventions performed with the retrospective study.

MEASUREMENTS

Number of total central venous catheters, number of central venous catheters that received treatment with alteplase, and number of CBSIs.

MAIN RESULTS

Preliminary data during the study period identified 3,289 central venous catheters. Twelve percent of these catheters required at least one dose of alteplase. There were 40 CBSIs during this same time period of which 28% received alteplase during the 5 days preceding the positive blood culture. The odds ratio for getting a CBSI when alteplase is administered is 2.87 (confidence interval 1.42-5.80; p = 0.002). The average age of the central venous catheters at time of infection was not statistically different, 16.1 days in the alteplase catheters compared with 25.6 days for the catheters that did not receive alteplase (p = 0.6).

CONCLUSIONS

There is a positive correlation between the use of alteplase for malfunctioning central venous catheters and the development of a CASBI. This is likely associated with the presence of an intraluminal fibrin sheath or thrombus. This study adds evidence linking thrombus formation to CBSI.

Do children with central venous line (CVL) dysfunction have increased risk of symptomatic thromboembolism compared to those without CVL-dysfunction, while on cancer therapy?

Background

Thromboembolism (TE) and infection are two common complications of central venous line (CVL). Thrombotic CVL-dysfunction is a common, yet less studied, complication of CVL. Two retrospective studies have reported significant association of CVL-dysfunction and TE. Recent studies indicate association of CVL-related small clot with infection. Infection is the most common cause of non-cancer related mortality in children with cancer. We and others have shown reduced overall survival (OS) in children with cancer and CVL-dysfunction compared to those without CVL-dysfunction. Despite these observations, to date there are no prospective studies to evaluate the clinical significance of CVL-dysfunction and it’s impact on the development of TE, infection, or outcome of children with cancer.

Study design

This is a prospective, analytical cohort study conducted at five tertiary care pediatric oncology centers in Ontario. Children (≤ 18 years of age) with non-central nervous system cancers and CVL will be eligible for the study. Primary outcome measure is symptomatic TE and secondary outcomes are infection, recurrence of cancer and death due to any cause. Data will be analyzed using regression analyses.

Discussion

The overall objective is to delineate the relationship between CVL-dysfunction, infection and TE. The primary aim is to evaluate the role of CVL-dysfunction as a predictor of symptomatic TE in children with cancer. We hypothesize that children with CVL-dysfunction have activation of the coagulation system resulting in an increased risk of symptomatic TE. The secondary aims are to study the impact of CVL-dysfunction on the rate of infection and the survival [OS and event free survival (EFS)] of children with cancer. We postulate that patients with CVL-dysfunction have an occult CVL-related clot which acts as a microbial focus with resultant increased risk of infection. Further, CVL-dysfunction by itself or in combination with associated complications may cause therapy delays resulting in adverse outcome.

This study will help to identify children at high risk for TE and infection. Based on the study results, we will design randomized controlled trials of prophylactic anticoagulant therapy to reduce the incidence of TE and infection. This in turn will help to improve the outcome in children with cancer.

Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Neonates and children differ from adults in physiology, pharmacologic responses to drugs, epidemiology, and long-term consequences of thrombosis. This guideline addresses optimal strategies for the management of thrombosis in neonates and children.

METHODS

The methods of this guideline follow those described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

RESULTS

We suggest that where possible, pediatric hematologists with experience in thromboembolism manage pediatric patients with thromboembolism (Grade 2C). When this is not possible, we suggest a combination of a neonatologist/pediatrician and adult hematologist supported by consultation with an experienced pediatric hematologist (Grade 2C). We suggest that therapeutic unfractionated heparin in children is titrated to achieve a target anti-Xa range of 0.35 to 0.7 units/mL or an activated partial thromboplastin time range that correlates to this anti-Xa range or to a protamine titration range of 0.2 to 0.4 units/mL (Grade 2C). For neonates and children receiving either daily or bid therapeutic low-molecular-weight heparin, we suggest that the drug be monitored to a target range of 0.5 to 1.0 units/mL in a sample taken 4 to 6 h after subcutaneous injection or, alternatively, 0.5 to 0.8 units/mL in a sample taken 2 to 6 h after subcutaneous injection (Grade 2C).

CONCLUSIONS

The evidence supporting most recommendations for antithrombotic therapy in neonates and children remains weak. Studies addressing appropriate drug target ranges and monitoring requirements are urgently required in addition to site- and clinical situation-specific thrombosis management strategies.

Thrombolytic therapy for central venous catheter occlusion

BACKGROUND

Long-term central venous catheters have improved the quality of care for patients with chronic illnesses, but are complicated by obstructions which can result in delay of treatment or catheter removal.

DESIGN AND METHODS

This paper reviews thrombolytic treatment for catheter obstruction. Literature from Medline searches using the terms "central venous catheter", "central venous access device" OR "central venous line" associated with the terms "obstruction", "occlusion" OR "thrombolytic" was reviewed. Efficacy of thrombolytic therapy, central venous catheter clearance rates and time to clearance were assessed.

RESULTS

Alteplase, one of the current therapies, clears 52% of obstructed catheters within 30 min with 86% overall clearance (after 2 doses, when necessary). However, newer medications may have higher efficacy or shorter time to clearance. Reteplase cleared 67-74% within 30-40 min and 95% of catheters overall. Occlusions were resolved in 70 and 83% of patients with one and 2 doses of tenecteplase, respectively. Recombinant urokinase cleared 60% of catheters at 30 min and 73% overall. Alfimeprase demonstrated rapid catheter clearance with resolution in 40% of subjects within 5 min, 60% within 30 min, and 80% within 2 h. Additionally, urokinase prophylaxis decreased the incidence of catheter occlusions from 16-68% in the control group to 4-23% in the treatment group; in some studies, rates of catheter infections were also decreased in the urokinase group.

CONCLUSIONS

Thrombolytic agents successfully clear central venous catheter occlusions in most cases. Newer agents may act more rapidly and effectively than currently utilized therapies, but randomized studies with direct comparisons of these agents are needed to determine optimal management for catheter obstruction.

Proteases as therapeutics

Proteases are an expanding class of drugs that hold great promise. The U.S. FDA (Food and Drug Administration) has approved 12 protease therapies, and a number of next generation or completely new proteases are in clinical development. Although they are a well-recognized class of targets for inhibitors, proteases themselves have not typically been considered as a drug class despite their application in the clinic over the last several decades; initially as plasma fractions and later as purified products. Although the predominant use of proteases has been in treating cardiovascular disease, they are also emerging as useful agents in the treatment of sepsis, digestive disorders, inflammation, cystic fibrosis, retinal disorders, psoriasis and other diseases. In the present review, we outline the history of proteases as therapeutics, provide an overview of their current clinical application, and describe several approaches to improve and expand their clinical application. Undoubtedly, our ability to harness proteolysis for disease treatment will increase with our understanding of protease biology and the molecular mechanisms responsible. New technologies for rationally engineering proteases, as well as improved delivery options, will expand greatly the potential applications of these enzymes. The recognition that proteases are, in fact, an established class of safe and efficacious drugs will stimulate investigation of additional therapeutic applications for these enzymes. Proteases therefore have a bright future as a distinct therapeutic class with diverse clinical applications.

Anticoagulation for patients with cancer and central venous catheters

BACKGROUND

Central venous catheter (CVC) placement increases the risk of thrombosis in cancer patients. Thrombosis often necessitates the removal of the CVC, resulting in treatment delays and thrombosis related morbidity and mortality.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulation in cancer patients with a CVC.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1 2010), MEDLINE (January 1966 to February 2010; accessed via OVID), EMBASE (January 1980 to February 2010; accessed via OVID) and ISI the Web of Science (1975 to February 2010). We handsearched conference proceedings, checked references of included studies and used the "related article" feature within PubMed.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing any dose of unfractionated heparin (UFH), low molecular weight heparin (LMWH), vitamin K antagonists (VKA), or fondaparinux to no intervention or placebo or comparing two different anticoagulants in cancer patients with a CVC.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each included study and resolved their disagreements by discussion.

MAIN RESULTS

Of 8187 identified citations, we included 12 RCTs enrolling 3611 patients and assessing either prophylactic dose heparin or low dose VKAs. Prophylactic dose heparin was not associated with a statistically significant effect on death (relative risk (RR) = 0.85; 95% confidence interval (CI): 0.53 to 1.37), symptomatic deep venous thrombosis (DVT) (RR = 0.54; 95% CI: 0.28 to 1.05) asymptomatic DVT (RR = 0.81; 95% CI: 0.64 to 1.02), major bleeding (RR = 0.68; 95% CI: 0.10 to 4.78), thrombocytopenia (RR = 0.85; 95% CI: 0.49 to 1.46), or infection (RR = 0.91; 95% CI: 0.49 to 1.68). Similarly, low dose VKAs were not associated with a statistically significant effect on death (RR = 0.97; 95% CI: 0.82 to 1.15), symptomatic DVT (RR = 0.63; 95% CI: 0.35 to 1.11) or major bleeding (RR = 6.93; 95% CI: 0.86 to 56.08). However, they were associated with a statistically significant reduction in asymptomatic DVT (RR = 0.42; 95% CI: 0.28 to 0.61). Studies comparing heparin to VKA found no effects on any of the outcomes of interest.

AUTHORS' CONCLUSIONS

We found no statistically significant effect of heparin or VKA on the outcomes of interest. However, the findings did not rule out clinically important benefits and harms. Patients with cancer with CVCs considering anticoagulation should balance the possible benefit of reduced thromboembolic complications with the possible harms and burden of anticoagulants.

Anticoagulation for patients with cancer and central venous catheters

BACKGROUND

Central venous catheter (CVC) placement increases the risk of thrombosis in cancer patients. Thrombosis often necessitates the removal of the CVC, resulting in treatment delays and thrombosis related morbidity and mortality.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulation in cancer patients with a CVC.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1 2010), MEDLINE (January 1966 to February 2010; accessed via OVID), EMBASE (January 1980 to February 2010; accessed via OVID) and ISI the Web of Science (1975 to February 2010). We handsearched conference proceedings, checked references of included studies and used the "related article" feature within PubMed.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing any dose of unfractionated heparin (UFH), low molecular weight heparin (LMWH), vitamin K antagonists (VKA), or fondaparinux to no intervention or placebo or comparing two different anticoagulants in cancer patients with a CVC.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each included study and resolved their disagreements by discussion.

MAIN RESULTS

Of 8187 identified citations, we included 12 RCTs enrolling 3611 patients and assessing either prophylactic dose heparin or low dose VKAs. Prophylactic dose heparin was not associated with a statistically significant effect on death (relative risk (RR) = 0.85; 95% confidence interval (CI): 0.53 to 1.37), symptomatic deep venous thrombosis (DVT) (RR = 0.54; 95% CI: 0.28 to 1.05) asymptomatic DVT (RR = 0.81; 95% CI: 0.64 to 1.02), major bleeding (RR = 0.68; 95% CI: 0.10 to 4.78), thrombocytopenia (RR = 0.85; 95% CI: 0.49 to 1.46), or infection (RR = 0.91; 95% CI: 0.49 to 1.68). Similarly, low dose VKAs were not associated with a statistically significant effect on death (RR = 0.97; 95% CI: 0.82 to 1.15), symptomatic DVT (RR = 0.63; 95% CI: 0.35 to 1.11) or major bleeding (RR = 6.93; 95% CI: 0.86 to 56.08). However, they were associated with a statistically significant reduction in asymptomatic DVT (RR = 0.42; 95% CI: 0.28 to 0.61). Studies comparing heparin to VKA found no effects on any of the outcomes of interest.

AUTHORS' CONCLUSIONS

We found no statistically significant effect of heparin or VKA on the outcomes of interest. However, the findings did not rule out clinically important benefits and harms. Patients with cancer with CVCs considering anticoagulation should balance the possible benefit of reduced thromboembolic complications with the possible harms and burden of anticoagulants.

IV Catheter Care and Maintenance Minimizes Catheter-Related Blood Stream Infection

The elimination of catheter-related bloodstream infections (CR-BSI) requires meticulous intravenous (IV) catheter care. There are three different types of needlefree connectors and one intraluminal protection device that require different care regimens, including the correct usage of disinfectants, flushing techniques, and clamping sequences. The nurse must be able to identify which connector is in use and select the appropriate care. This care must be followed not only in the inpatient unit by the bedside nurse but also in areas that are providing diagnostic procedures such as the cardiac cath lab. Since bacterial adhesion to the intraluminal catheter wall is the primary building block of a CR-BSI, which may not present until days after initial inoculation, preventing intraluminal fluid pathway contamination is paramount with every access. In addition, many institutions have more than one type of connector available. This complicates the provision of consistent safe care. Split septum, negative mechanical valves, positive pressure mechanical valves, and intraluminal protection devices have specific care and maintenance requirements. This article discusses the different connector types, why each requires special care, how intraluminal fluid pathway contamination can lead to CR-BSI, and how simple nursing care and maintenance practices of connector septum swabbing and catheter flushing by the cardiac cath nurse can help prevent this serious complication.

Interventions other than anticoagulants and systemic antibiotics for prevention of central venous catheter-related infections in children with cancer

BACKGROUND

Use of central venous catheters (CVC) in treatment of children with cancer is associated with infective complications. Current evidence-based guidelines to prevent catheter-related infections are mainly relevant to the adult population. They are not cancer (especially not childhood cancer) specific. Two existing Cochrane reviews have looked at prophylactic antibiotics and anticoagulants to prevent CVC-related infections.

OBJECTIVES

The primary objective was to find which interventions, if any, were effective in preventing CVC-related infections in children with cancer. Further objectives were to examine the effectiveness of each intervention in the following subgroups: implanted versus external catheters, haematological versus non-haematological malignancies, and in those receiving haematopoietic stem cell transplants (HSCT) versus no HSCT.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2008, Issue 4), MEDLINE (January 1950 to January 2009), EMBASE (January 1980 to January 2009) and CINAHL(R) (January 1982 to March 2009). We also searched reference lists of relevant articles and proceedings of relevant international conferences (2004 to 2008).

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing any intervention (other than anticoagulants, systemic antibiotics and antibiotic lock techniques) versus no intervention, placebo or any other intervention to prevent CVC-related infections in children with cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, assessed trial quality and extracted data. Where necessary, we contacted study authors for further data and clarification of methods.

MAIN RESULTS

Three trials involving two different interventions were included. Two trials involving 680 children compared flushing CVC with urokinase (with or without heparin) versus heparin alone. Neither of these trials reported on the primary outcome of catheter-related blood stream infection (CRBSI). There was a non-significantly decreased rate of catheter-associated infection (CAI) (Rate Ratio 0.72, 95% confidence interval 0.12 to 4.41) in the urokinase (with or without heparin) arm compared with the heparin arm.One trial involving 113 children compared frequency of catheter dressing change every 15 days versus every 4 days. It did not report on CRBSI or CAI. There were no premature catheter removals for infection in either of the trial arms.

AUTHORS' CONCLUSIONS

Three RCTs for only two types of interventions to prevent CVC-related infections in children with cancer have been identified. Flushing CVC with urokinase (with or without heparin) compared to heparin alone possibly leads to decrease in CAI rates. Changing catheter dressings every 15 days versus every 4 days does not lead to more premature catheter removals due to infection although data were insufficient to assess if catheter-related infection rates were changed.

Risk factors for central venous catheter thrombotic complications in children and adolescents with cancer

BACKGROUND

The use of central venous catheters (CVCs) has greatly improved the quality of care in children with cancer, yet these catheters may cause serious infectious and thrombotic complications. The aim of this prospective registry study was to assess the host and CVC-related risk factors for CVC-created thrombotic complications.

METHODS

Patients undergoing CVC insertion for chemotherapy were followed prospectively for CVC complications. At the time of enrollment, demographic, clinical, and CVC-related data, and family history of thrombosis were collected. Survival and Cox regression analyses were performed.

RESULTS

A total of 423 CVCs were inserted into 262 patients for a total of 76,540 catheter days. The incidence of CVC-related deep-vein thrombosis (DVT) was 0.13 per 1000 catheter-days (95% confidence interval [CI], 0.06-0.24). Insertion of peripherally inserted central catheters (PICCs) and insertion in an angiography suite significantly increased the risk of symptomatic CVC-related DVT. The incidence of CVC occlusion was 1.35 per 1000 catheter-days (95% CI, 1.1-1.63). Positive family history of thrombosis significantly increased the risk of CVC occlusion (hazard ratio [HR], 2.16; 95% CI, 1.2-3.8). The CVC-related risk factors were insertion of Hickman catheters, insertion in angiography suite, and proximal-tip location. Patients developing at least 1 episode of both CVC occlusion and infection had an increased risk for developing symptomatic CVC-related DVT (HR, 4.15; 95% CI, 1.2-14.4).

CONCLUSIONS

Both patient-related and CVC-related factors are associated with higher risk of symptomatic thrombotic complications. These risk factors could be used in the clinical setting and in developing future studies for CVC thromboprophylaxis.

The Impact of IV Connectors on Clinical Practice and Patient Outcomes

It has only been during the past decade that contamination of the intraluminal fluid pathway has gained recognition as a cause of CR-BSI. The IV connector is the gate keeper of the intraluminal fluid pathway. The care and maintenance of catheters is the complete responsibility of the primary nurse. The primary CR-BSI causative agent is biofilm formation. Biofilm formation depends on the number of cells, the presence of surface conditioning and the flow rate of the solution. Staph epidermis, and Staph aureus have surface cell receptors which assist in fibrin, fibrinogen location enabling the microorganisms to successfully adhere. Therefore, intraluminal contamination prevention strategies must be two-pronged - to prevent active and passive microorganism migration into the intaluminal fluid pathway and to prevent microorganism adhesion by minimizing fibrin build-up on the internal surface. The two care and maintenance procedures nurses use to protect the intraluminal pathway are swabbing the connector septum and flushing the connector after use. Individualizing the care based on the patient has not been studied. Since every patient is unique, different catheters and connectors are used, and even the nurse's experience and knowledge are different, achieving consistent positive outcomes using a one-size-fits-all approach has shown to have inconsistent outcomes. An overview of swabbing and flushing is discussed and then how IV connector design affects these practice and outcomes is reviewed. It is imperative to recognize what procedures are performed for improved patient outcomes, versus what procedures are performed to overcome IV connector design features. If flushing and swabbing procedures are standardized to general time requirements alone and connector design is overlooked, it should be understood that outcomes may vary and this variance may not be related to inconsistent nursing adherence to IV connector related swabbing and flushing procedures.

A continuous heparin infusion does not prevent catheter-related thrombosis in infants after cardiac surgery

OBJECTIVE

To determine whether a continuous infusion of heparin reduces the rate of catheter-related thrombosis in neonates and infants post cardiac surgery. Central venous and intracardiac catheters are used routinely in postoperative pediatric cardiac patients. Catheter-related thrombosis occurs in 8% to 45% of pediatric patients with central venous catheters.

DESIGN

Single-center, randomized, placebo-controlled, double-blinded trial.

SETTING

Cardiovascular intensive care unit, university-affiliated children's hospital.

PATIENTS

Children <1 yr of age recovering from cardiac surgery.

INTERVENTIONS

Patients were randomized to receive either continuous heparin at 10 units/kg/hr or placebo. The primary end point was catheter-related thrombosis as assessed by serial ultrasonography.

RESULTS

Study enrollment was discontinued early based on results from an interim futility analysis. Ninety subjects were enrolled and received the study drug (heparin, 53; placebo, 37). The catheter-related thrombosis rate in the heparin group, compared with the placebo group, was 15% vs. 16% (p = .89). Subjects in the heparin group had a higher mean partial thromboplastin time (52 secs vs. 42 secs, p = .001), and this difference was greater for those aged <30 days (64 secs vs. 43 secs, p = .008). Catheters in place > or = 7 days had both a greater risk of thrombus formation (odds ratio, 4.3; p = .02) and catheter malfunction (odds ratio, 11.2; p = .008). We observed no significant differences in other outcome measures or in the frequency of adverse events.

CONCLUSIONS

A continuous infusion of heparin at 10 units/kg/hr was safe but did not reduce catheter-related thrombus formation. Heparin at this dose caused an increase in partial thromboplastin time values, which, unexpectedly, was more pronounced in neonates.

Prolonged interval in prophylactic heparin flushing for maintenance of subcutaneous implanted port care in patients with cancer

The long-term use of subcutaneous implanted ports for chemotherapy in cancer patients has been associated with the occurrence of thrombosis and infection. In this study, we compared the safety and efficacy of administration of 1000 U of heparin flushes in prolonged interval (every 6 weeks) with standard dose and schedule (500 U every 4 weeks) for port-related infections and thrombosis during periods of non-use. Data were collected retrospectively from patients treated for various cancer types (matched as 2:1 for age, gender, stage of the disease). Patients who had diseases that could cause thrombosis or bleeding in their past medical history, or were taking oral anticoagulants, or had contraindications for heparin usage were excluded. After completing their chemotherapy, 59 patients received prolonged interval, while 30 patients received standard schedule. All patients were followed for at least 1 year. No clinically documented port-related infection or thrombosis has been found in both groups. Also, none of the devices was removed during this time. Prophylactic flushing of central venous ports with 1000 U of heparin in every 6 weeks might be a safe, easy, cheaper, comfortable and effective alternative to standard dose and schedule for preventing thrombosis and infections.

Thrombosis in childhood acute lymphoblastic leukaemia: epidemiology, aetiology, diagnosis, prevention and treatment

Acute lymphoblastic leukaemia (ALL) is the most common malignancy associated with venous thromboembolism (VTE) in children. The prevalence of symptomatic VTE ranges from 0% to 36%, and the variation can be explained, at least in part, by differences in chemotherapeutic protocols. The mechanism for increased risk of VTE is associated with alterations in the haemostatic system by use of L-asparaginase (ASP) alone or in combination with vincristine or prednisone, presence of central venous lines (CVLs) and/or inherited thrombophilia. The children at greatest risk are generally those receiving Escherichia coli ASP concomitant with prednisone. The majority of symptomatic VTEs occur in the central nervous system or in the upper venous system. In the majority of cases, asymptomatic VTEs are associated with CVLs. External CVLs are affected more often than internal CVLs. Evidence-based guidelines on prevention and treatment guidelines for ALL-related VTE are lacking, and carefully designed clinical trials are needed urgently.

Management of occlusion and thrombosis associated with long-term indwelling central venous catheters

Long-term central venous catheters (CVCs) are important instruments in the care of patients with chronic illnesses, but catheter occlusions and catheter-related thromboses are common complications that can result from their use. In this Review, we summarise management of these complications. Mechanical CVC occlusions need cause-specific treatment, whereas thrombotic occlusions usually resolve with thrombolytic treatment, such as alteplase. Prophylaxis with thrombolytic flushes might prevent CVC infections and catheter-related thromboses, but confirmatory studies and cost-effectiveness analysis of this approach are needed. Risk factors for catheter-related thromboses include previous catheter infections, malposition of the catheter tip, and prothrombotic states. Catheter-related thromboses can lead to catheter infection, pulmonary embolism, and post-thrombotic syndrome. Catheter-related thromboses are usually diagnosed by Doppler ultrasonography or venography and treated with anticoagulation therapy for 6 weeks to a year, dependent on the extent of the thrombus, response to initial therapy, and whether thrombophilic factors persist. Prevention of catheter-related thromboses includes proper positioning of the CVC and prevention of infections; anticoagulation prophylaxis is not currently recommended.

Thrombosis in the critically ill neonate: incidence, diagnosis, and management

Among children, newborn infants are most vulnerable to development of thrombosis and serious thromboembolic complications. Amongst newborns, those neonates who are critically ill, both term and preterm, are at greatest risk for developing symptomatic thromboembolic disease. The most important risk factors are inflammation, DIC, impaired liver function, fluctuations in cardiac output, and congenital heart disease, as well as exogenous risk factors such as central venous or arterial catheters. In most clinically symptomatic infants, diagnosis is made by ultrasound, venography, or CT or MRI angiograms. However, clinically asymptomatic vessel thrombosis is sometimes picked up by screening investigations or during routine imaging for other indications. Acute management of thrombosis and thromboembolism comprises a variety of approaches, including simple observation, treatment with unfractionated or low molecular weight heparin, as well as more aggressive interventions such as thrombolytic therapy or catheter-directed revascularization. Long-term follow-up is dependent on the underlying diagnosis. In the majority of infants, stabilization of the patients’ general condition and hemodynamics, which allows removal of indwelling catheters, renders long-term anticoagulation superfluous. Nevertheless, in certain types of congenital heart disease or inherited thrombophilia, long-term prophylaxis may be warranted. This review article focuses on pathophysiology, diagnosis, and acute and long-term management of thrombosis in critically ill term and preterm neonates.

Prospective, randomized trial of two different modalities of flushing central venous catheters in pediatric patients with cancer

PURPOSE

There are limited prospective data on whether the method of flushing affects the complication rate of tunnelled central venous catheters (CVCs).

PATIENTS AND METHODS

During a 25-month period, 203 pediatric patients who had newly placed Broviac-Hickman CVCs were randomly assigned to standard flushing with heparin solution or to experimental flushing with normal saline via a positive-pressure cap.

RESULTS

Two hundred twenty-one complications were recorded among 75,249 CVC-days (2.94 per 1,000 CVC-days). A higher incidence of CVC occlusion (83 v 41 episodes; P = .0002) and bacteremia (24 v 9; P = .01) were found in the experimental arm. The cumulative probability of developing at least one CVC complication was higher in the experimental arm than in the standard arm (65.1% [95% CI, 55% to 75%] v 43.8% [95% CI, 34% to 54%], respectively; P = .01). No difference was found in either the cause or the frequency of premature removal of CVCs between the two study arms. After a median follow-up of 360 days (range, 4 to 1,073), CVC survival was similar: 77% (95% CI, 66% to 84%) for the experimental arm and 69% (95% CI, 53% to 80%) for the standard arm (P = .7). The factors associated with the occurrence of CVC complication were a diagnosis of leukemia/lymphoma, double-lumen CVC, and experimental flushing. The only factor significantly associated with premature removal of a CVC was a diagnosis of leukemia/lymphoma (hazard rate, 2.3; 95% CI, 1.1 to 4.7).

CONCLUSION

An increased complication rate was found with normal saline flushing, but additional investigation is warranted to clarify whether it is related to saline use or to once-a-week flushing.