Central Venous Lines in Children With Lesser Risk Acute Lymphoblastic Leukemia: Optimal Type and Timing of Placement

Central-line-associated bloodstream infections and central-line-associated non-CLABSI complications among pediatric oncology patients

OBJECTIVE

To assess central venous catheter (CVC) harm in pediatric oncology patients, we explored risks for central-line-associated bloodstream infections (CLABSIs) and central-line-associated non-CLABSI complications (CLANCs).

DESIGN

Retrospective cohort study.

SETTING

Midwestern US pediatric oncology program.

PATIENTS

The study cohort comprised 592 pediatric oncology patients seen between 2006 and 2016.

METHODS

CLABSIs were defined according to Centers for Disease Control and Prevention (CDC)/National Health Safety Network (NHSN) definitions. CLANCs were classified using a novel definition requiring CVC removal. Patient-level and central-line-level risks were calculated using a negative binomial model to adjust for correlations between total events and line numbers.

RESULTS

CVCs were inserted in 62% of patients, with 175,937 total catheter days. The inpatient CLABSI and CLANC rates were 5.8 and 8.5 times higher than outpatient rates. At the patient level, shared risks included acute myeloid leukemia (AML) and age <1 year at diagnosis. At the line level, shared risks included age <1 year at diagnosis, non-mediports, and >1 lumen. AML was a CLABSI-specific risk. CLANC-specific risks included non-brain-tumor diagnosis, younger age at diagnosis or central-line placement, and age <1 year at diagnosis or line placement. Multivariable risks were for CLABSI >1 lumen and for CLANC age <1 year at placement.

CONCLUSIONS

Among patients with CVCs, CLABSI and CLANC rates were similar, higher among inpatients than outpatients. For both CLABSIs and CLANCs, infants and patients with AML were at higher risk. In both univariate and multivariate models, lines with >1 lumen were associated with CLABSIs and placement during infancy with CLANCs.

Pediatric cancer-associated thrombosis: Analysis from a tertiary care cancer center in India

BACKGROUND AND AIMS

Thrombotic events (TEs) have been extensively studied in adult cancer patients, but data in children are limited. We prospectively analyzed pediatric cancer-associated thrombosis (PCAT) in children with malignancies.

METHODS

Children below 15 years of age with confirmed malignancies, treated at a large tertiary cancer center in India from July 2015 to March 2020 developing any TE were eligible. A standardized approach for detection and management was followed. Data were collected after informed consent.

RESULTS

Of 6132 eligible children, 150 (2.44%) had 152 TEs, with median age 8.5 years and male:female of 1.83:1. Most TEs occurred on chemotherapy: 111 (74.0%). The most common site was central nervous system (CNS) 59 (39.3%), followed by upper-limb venous system 37 (24.7%). Hemato-lymphoid (HL) malignancies were more prone to PCAT than solid tumors (ST) (incidence 3.23% vs. 1.58%; odds ratio [OR] = 2.06, 95% confidence interval [CI] [1.36-2.88]; p < .001). Malignancies associated with PCAT were acute lymphoblastic leukemia (ALL) 2.94%, acute myeloid leukemia (AML) 6.66%, and non-Hodgkin lymphomas 5.35%. Response imaging done in 106 (70.7%) children showed complete to partial resolution in almost 90% children. Death was attributable to TE in seven (4.66%) children. Age above 10 years (OR 2.33, 95% CI [1.59-3.41]; p < .001), AML (OR 4.62, 95% CI [1.98-10.74]; p = .0062), and non-Hodgkin lymphoma (OR 4.01, 95% CI [1.15-14.04]; p = .029) were significantly associated with TEs. In ALL, age more than 10 years (OR 1.86, 95% CI [1.06-3.24]; p < .03), T-ALL (OR 3.32, 95% CI [1.69-6.54]; p = .001), and intermediate-risk group (OR 4.97, 95% CI [1.12-22.02]; p = .035) were significantly associated with thrombosis. The 2-year event-free survival (EFS) for HL malignancies with PCAT was 55.3% versus 72.1% in those without PCAT (p = .05), overall survival (OS) being 84.6% versus 80.0% (p = .32).

CONCLUSION

Incidence of PCAT was 2.4%, and occurred predominantly in older children with hematolymphoid malignancies early in treatment. Most resolved completely with low molecular weight heparin (LMWH) and mortality was low. In hematolymphoid malignancies, PCAT reduce EFS, highlighting the need for prevention.

Timing of Central Venous Line Insertion During Induction in Children With Acute Lymphoblastic Leukemia

PURPOSE

Central venous lines (CVL) in children with acute lymphoblastic leukemia (ALL) provide comfortable administration of intensive chemotherapy and blood sampling. The optimal time for the insertion of CVL in patients with ALL during induction therapy is controversial. This study aimed to investigate the frequency of CVL-related complications in children with ALL concerning the time of CVL insertion.

PATIENTS AND METHODS

We reviewed the records of 52 pediatric ALL patients with CVL. CVL placement before or on treatment day 15 was defined as "early insertion", and after treatment day 15 was defined as "late insertion". Demographics, preoperative blood counts, type of central line, time of CVL placement, CVL-related complications, and blood counts during complications were all noted. All the data were collected from those with the first catheter use.

RESULTS

CVL was placed ≤15 days in 26 patients (50%) and after 15 days in 26 patients (50%). Regarding the infection rates, no statistical difference was found between early and late CVL-inserted groups ( P =n.s.). Five patients developed thrombosis, and risk was found to be similar between early and late CVL-inserted groups ( P =n.s.). Catheter-related mechanical complications were recorded in 7 patients (3 in early and 4 in late CVL-inserted group, ( P =n.s.).

CONCLUSION

The present study showed no relation between the timing of CVL placement during induction therapy and the occurrence of infection and thrombosis. Our results suggest that CVL can be placed safely at the time of diagnosis or early induction treatment to provide a comfortable administration of chemotherapy and decrease painful blood samplings.

Analysis of related complications of totally implantable venous access ports in children's chemotherapy: Single center experience

Totally implantable venous access port (TIVAP) has become an important infusion channel for children who need chemotherapy. With the popularization of TIVAP, its related complications have gradually received clinical attention. However, there are few studies on the complications of TIVAP in children. Therefore, this study intends to analyze the risk factors of complications in children's infusion port, so as to provide basis for guiding clinical prevention and intervention. This paper retrospectively analyzed 182 children who received TIVAP implantation in our hospital from January 2018 to January 2021. According to the demographic data, basic disease status and operation related data obtained through Hospital Information System and manual follow-up, the complications and related influencing factors after implantation and implantation were summarized and analyzed. SPSS software was used to analyze the influencing factors between the complication group and the control group. There were 182 cases of children implanted in intravenous infusion port, of which 71 cases had complications, infection was the most common complication in 50 cases, followed by catheter blockage in 23 cases. Among the infection factors, catheter-related blood stream infection accounted for the highest proportion in 31 cases (17.0%), and Staphylococcus epidermidis was the most common pathogen. A total of 19 cases were pulled out early, and the unplanned pullout rate of catheter-related blood stream infection was the highest. In the analysis of influencing factors, age had significant differences in catheter-related infection, all complications and no complications (P < .05). The overall incidence of complications in the use of TIVAP in children with chemotherapy is high, and infection is the most common complication, among which catheter-related blood stream infection is the most common cause of unplanned pullout. Lower age may be associated with a higher incidence of complications.

High Rates of Central Venous Line Replacement or Revision in Children With Cancer at US Children's Hospitals

BACKGROUND

Most children with cancer utilize a central venous line (CVL) for treatment. Complications often necessitate early replacement, revision, or addition (RRA), but the rate of these procedures is not known. This study sought to determine rates of RRA in pediatric oncology patients, and associated risk factors.

MATERIALS AND METHODS

Data queried from the Pediatric Health Information System including patients ≤18 years old with malignancy and CVL placement. Analysis included: first CVL placement of the calendar year and subsequent procedures for 6 months thereafter.

RESULTS

A total of 6553 children met inclusion criteria (55.9% male, median age 6 years, interquartile range: 2 to 12). RRA within 6 months was required in 25.6% of patients, with 1.7% requiring 5 or more lines. Patients with Central Line-Associated Bloodstream Infection (CLABSI) were 2.78 times more likely to require RRA within 6 months of initial CVL placement, but accounted for only 16% of RRA patients. Factors associated with RRA were age below 1 year, CLABSI, hematologic malignancy, malnutrition, clotting disorder, deep vessel thromboembolism, and obesity. Patients with implantable ports as initial CVL (42%) were less likely to need RRA.

CONCLUSION

Twenty-five percent require at least 1 RRA within 6 months, with associated morbidity and costs. Though strongly associated, most revisions were not related to CLABSI episodes.

Thrombosis Complications in Pediatric Acute Lymphoblastic Leukemia: Risk Factors, Management, and Prevention: Is There Any Role for Pharmacologic Prophylaxis?

Pediatric acute lymphoblastic leukemia (ALL) has achieved close to 90% cure rates through extensive collaborative and integrative molecular research, clinical studies, and advances in supportive care. Despite this high achievement, venous thromboembolic complications (VTE) remain one of the most common and potentially preventable therapy-associated adverse events in ALL. The majority of thromboses events involve the upper central venous system which is related to the use and location of central venous catheters (CVC). The reported rates of symptomatic and asymptomatic CVC-related VTE range from 2.6 to 36.7% and 5.9 to 43%, respectively. Thrombosis can negatively impact not only disease-free survival [e.g., therapy delays and/or interruption, omission of chemotherapy agents (e.g., asparaginase therapy)] but also can result in long-term adverse effects that can impair the quality of life of ALL survivors (e.g., post-thrombotic syndrome, central nervous system (CNS)-thrombosis related complications: seizures, neurocognitive deficits). In this review, will discuss thrombosis pathophysiology in pediatric ALL, risk factors, treatment, and prevention strategies. In addition, the recently published clinical efficacy and safety of direct oral anticoagulants (DOACs) use in thrombosis treatment, and their potential role in primary/secondary thrombosis prevention in pediatric patients with ALL will be discussed. Future clinical trials involving the use of these novel oral anticoagulants should be studied in ALL not only for primary thrombosis prevention but also in the treatment of thrombosis and its secondary prevention. These future research findings could potentially extrapolate to VTE prevention strategies in other pediatric cancer diagnoses and children considered at high risk for VTE.

Catheter related thrombosis in hospitalized infants: A neural network approach to predict risk factors

INTRODUCTION

We sought to investigate the predictors of catheter-related thrombosis (CRT) in a cohort of critically ill hospitalized infants and using a novel approach (the artificial neural network - ANN) in combination with conventional statistics to identify/confirm those predictors.

METHODS

We performed a retrospective analysis of all infants with a central or peripherally inserted central venous catheter (CVC/PICC) between 2015 and 2018. ANN was generated to investigate the predictors of CRT. The predictive variables examined in the ANN were age, gender, weight, co-morbid conditions, line type, use of ultrasound (USG), emergent line placement, location of line tip, any major surgical procedures, use of mechanical ventilation, exposure to cardio-pulmonary bypass (CPB), past-history of CVC/PICC, or thrombosis. Binary logistic regression was performed to calculate odds ratios (ORs) and determine which factors were significant in predicting CRT.

RESULTS

Of total of 613 infants, 59.9% of patients had a history of previous CVC or PICC and 12.2% had a history of thrombus as documented by USG in the past three months. CPB exposure was present in 48.1%. The incidence of CRT was 10.7%. Independent predictors of CRT were the line tip in IVC (OR: 2.37, 1.08-5.21, P = 0.032), history of thrombosis (OR: 2.40, 1.16-4.96, P = 0.019), previous CVC/PICC (OR: 2.80, 1.24-6.33, P = 0.014) and exposure to CPB (OR: 2.749, 1.08-6.98, P = 0.034). A sensitivity analysis was performed to determine the normalized importance of each variable used to create the ANN. The most important variables were age (with normalized importance of 100%), history of thrombosis, weight, and exposure to CPB (normalized importance of 68.2%).

CONCLUSIONS

Nearly 1 in 10 infants developed CRT. We found that catheter tip in IVC, exposure to CPB, history of vein thrombosis and history of CVC/PICC placement in the past 3 months are independently associated with a higher risk of CRT in infants by using conventional and neural network methods.

Instituting a New Central Line Policy to Decrease Central Line-associated Blood Stream Infection Rates During Induction Therapy in Pediatric Acute Lymphoblastic Leukemia Patients

BACKGROUND

Children with acute lymphoblastic leukemia (ALL) require central lines to facilitate their care. Peripherally inserted central catheters (PICCs) may have lower rates of central line-associated bloodstream infections (CLABSIs) versus other central lines.

OBJECTIVES

The objective of this study was to compare the CLABSI rate in the first month of therapy after initiating a policy to place PICCs in new patients with severe neutropenia (SN) and Mediports in those with moderate-to-no neutropenia. We also examined thrombosis rates.

DESIGN/METHOD

We prospectively gathered data on new patients for 2.5 years following the policy change and retrospectively for the 2 years prior and compared rates of CLABSIs and thrombosis.

RESULTS

CLABSIs decreased in SN patients from 7.52/1000 to 3.11/1000 line days (P=0.33). The CLABSI rate for all patients with SN who had a Mediport was 13.39/1000 versus 4.08/1000 line days for those that received PICCs (P=0.15). The thrombosis rate for Mediport patients was 3.13 clots/1000 versus 7.65/1000 line days for PICC patients, but the difference was not significant (P= 0.11).

CONCLUSION

The differences observed suggest that placing PICCs versus Mediports in new ALL patients with SN may result in a lower incidence of CLABSIs in the first month of therapy without a significant increase in thrombosis.

Cancer-associated thrombosis in pediatric patients

Childhood malignancy and especially acute lymphoblastic leukemia are increasingly associated with thromboembolism. The etiology of pediatric cancer associated thrombosis is multifactorial and may reflect a tumor mass effect, tumor thrombi, alterations of the hemostatic system, treatment-related hazards (e.g. procoagulant changes induced by chemotherapy), presence of central venous lines and comorbidities (e.g. inherited thrombophilia). With over 80% cure rates of childhood cancer, strategies for prevention as well as for early diagnosis and optimal treatment of thromboembolism in children with malignancies are of major importance. While the use of therapeutic low molecular weight heparin prevails, prospective studies regarding guidelines for treatment or prevention are currently lacking. This review will address the epidemiology, etiology and risk factors for thrombosis, describe the presently available evidence associated with current therapy, and offer a glimpse into future treatment options.

The effect of Absolute Neutrophil Count (ANC) on early surgical site infection in Implanted Central Venous Catheter (ICVC)

PURPOSE

The aim of this study was to evaluate surgical site infection (SSI) rates related to implanted central venous catheters (ICVC) in pediatric hematology and oncology patients with respect to absolute neutrophil count (ANC) levels.

PATIENTS AND METHODS

From January 2004 to December 2015, pediatric patients with ICVC insertion were investigated retrospectively. Patients were divided into four groups according to preoperative ANC levels and Granulocyte-colony stimulating factor (G-CSF) usage. Immediate and early surgical site infections were evaluated 7 and 30 days following surgery.

RESULTS

In total, 1143 patients were enrolled. Patients were placed into 4 groups: 930 patients in group 1 with an ANC≥500/μL without G-CSF, 149 in group 2 with an ANC≥500/μL after G-CSF usage, 36 in group 3 with an ANC<500/μL without G-CSF, and 28 in group 4 with an ANC<500/μL even after G-CSF administration. Rates of immediate and early SSIs were not statistically different between groups. In the two-group analysis (group 1 and 2 vs. 3 and 4), the number of immediate and early SSIs were not also different, respectively.

CONCLUSION

There was no correlation between ANC levels and immediate and early SSI occurrence after ICVC placement.

LEVEL OF EVIDENCE

III.

Low molecular weight heparin for prevention of central venous catheter-related thrombosis in children

BACKGROUND

The prevalence of children diagnosed with thrombotic events has been increasing in the last decades. The most common thrombosis risk factor in neonates, infants and children is the placement of a central venous catheter (CVC). It is unknown if anticoagulation prophylaxis with low molecular weight heparin (LMWH) decreases CVC-related thrombosis in children. This is an update of the Cochrane Review published in 2014.

OBJECTIVES

To determine the effect of LMWH prophylaxis on the incidence of CVC-related thrombosis and major and minor bleeding complications in children. Further objectives were to determine the effect of LMWH on occlusion of CVCs, number of days of CVC patency, episodes of catheter-related bloodstream infection (CRBSI), other side effects of LMWH (allergic reactions, abnormal coagulation profile, heparin-induced thrombocytopaenia and osteoporosis) and mortality during therapy.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 7 May 2019. We undertook reference checking of identified trials to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-randomised trials comparing LMWH to no prophylaxis (placebo or no treatment), or low-dose unfractionated heparin (UFH) either as continuous infusion or flushes (low-dose UFH aims to ensure the patency of the central line but has no systemic anticoagulation activity), given to prevent CVC-related thrombotic events in children. We selected studies conducted in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified eligible studies, which were assessed for study methodology including bias, and extracted unadjusted data where available. In the data analysis step, all outcomes were analysed as binary or dichotomous outcomes. The effects of interventions were summarised with risk ratios (RR) and their respective 95% confidence intervals (CI). We assessed the certainty of evidence for each outcome using the GRADE approach.

MAIN RESULTS

One additional study was included for this update bringing the total to two included studies (with 1135 participants). Both studies were open-label RCTs comparing LMWH with low-dose UFH to prevent CVC-related thrombosis in children. We identified no studies comparing LMWH with placebo or no treatment. Meta-analysis found insufficient evidence of an effect of LMWH prophylaxis in reducing the incidence of CVC-related thrombosis in children with CVC, compared to low-dose UFH (RR 0.68, 95% CI 0.27 to 1.75; 2 studies; 787 participants; low-certainty evidence). One study (158 participants) reported symptomatic and asymptomatic CVC-related thrombosis separately and detected no evidence of a difference between LMWH and low-dose UFH (RR 1.03, 95% CI 0.21 to 4.93; low-certainty evidence; RR 1.17, 95% CI 0.45 to 3.08; low-certainty evidence; for symptomatic and asymptomatic participants respectively). There was insufficient evidence to determine whether LMWH impacts the risk of major bleeding (RR 0.27, 95% CI 0.05 to 1.67; 2 studies; 813 participants; low-certainty evidence); or minor bleeding. One study reported minor bleeding in 53.3% of participants in the LMWH arm and in 44.7% of participants in the low-dose UFH arm (RR 1.20, 95% CI 0.91 to 1.58; 1 study; 158 participants; very low-certainty evidence), and the other study reported no minor bleeding in either group (RR: not estimable). Mortality during the study period was reported in one study, where two deaths occurred during the study period. Both were unrelated to thrombotic events and occurred in the low-dose UFH arm. The second study did not report mortality during therapy per arm but showed similar 5-year overall survival (low-certainty evidence). No additional adverse effects were reported. Other pre-specified outcomes (including CVC occlusion, patency and CRBSI) were not reported.

AUTHORS' CONCLUSIONS

Pooling data from two RCTs did not provide evidence to support the use of prophylactic LWMH for preventing CVC-related thrombosis in children (low-certainty evidence). Evidence was also insufficient to confirm or exclude a difference in the incidence of major and minor bleeding complications in the LMWH prophylaxis group compared to low-dose UFH (low and very low certainty respectively). No evidence of a clear difference in overall mortality was seen. Studies did not report on the outcomes catheter occlusion, days of catheter patency, episodes of CRBSI and other side effects of LMWH (allergic reactions, abnormal coagulation profile, heparin-induced thrombocytopaenia and osteoporosis). The certainty of the evidence was downgraded due to risk of bias of the included studies, imprecision and inconsistency, preventing conclusions in regards to the efficacy of LMWH prophylaxis to prevent CVC-related thrombosis in children.

Thrombosis in pediatric patients with leukemia

Acute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children. It is reportedly the most common malignancy associated with thromboembolism in the pediatric age group. Over the last 2 decades, venous thromboembolism (VTE) has been increasingly diagnosed among pediatric ALL patients with an estimated incidence ranging from about 5% (for symptomatic cases) to about 30-70% (following sequential imaging studies in asymptomatic children). The etiology is multifactorial and may stem from alterations of the hemostatic system following various chemotherapy protocols (including use of l-Asparaginase), the presence of central venous lines (CVL), as well as comorbidities, e.g. inherited thrombophilia risk factors. Most symptomatic thrombotic events occur in the upper venous system or in the central nervous system (CNS). Prospective studies on the establishment of guidelines for treatment or prevention are lacking. The following review will address the epidemiology, etiology and risk factors for thrombosis, describe the currently available evidence, and address issues associated with diagnosis and treatment.

Adverse effects of pegaspargase in pediatric patients receiving doses greater than 3,750 IU

BACKGROUND

Increased toxicities have been identified with higher doses of pegaspargase (PEG-ASP) in adults. This has led to routine use of a dose cap of 3,750 IU for adult acute lymphoblastic leukemia (ALL) patients in most institutions. In pediatric ALL patients, PEG-ASP is not capped. There is concern at our institution that larger doses may result in increased rates of adverse effects and that increased monitoring may be warranted in pediatric patients receiving doses greater than 3,750 IU. The objective of this study is to quantify the difference in the rates of PEG-ASP-associated adverse events between pediatric patients who received doses greater than 3,750 IU and less than or equal to 3,750 IU.

METHODS

Retrospective chart review of patients 1-21 years old with pre-B-cell ALL who received PEG-ASP between 2007 and 2014 at an academic medical center.

RESULTS

Of 183 patients included in the analysis, 24 received PEG-ASP doses higher than 3,750 IU and 159 received doses less than or equal to 3,750 IU. The incidence of venous thromboembolism (VTE) was significantly higher for patients in the group that received more than 3,750 IU compared with those who received 3,750 IU or less (20.8 vs. 1.89%, respectively; P = 0.0011). The incidence of pancreatitis (P = 0.0306) and hyperglycemia (P = 0.0089) were also higher in the group that received more than 3,750 IU.

CONCLUSIONS

PEG-ASP doses higher than 3,750 IU are associated with higher rates of VTE, pancreatitis, and hyperglycemia in pediatric patients with pre-B-cell ALL. Patients receiving more than 3,750 IU should have increased monitoring, and larger, multicenter trials are needed to determine if monitoring, VTE prophylaxis, and potential dose capping recommendations should be added to clinical trial protocols.

[Avoidance of complications when dealing with central venous catheters in the treatment of children]

Central venous catheters (CVCs) are an important tool in the treatment of children. The insertion of a catheter may result in different complications depending of the type of catheter, the technique used for the insertion and the location. There are various techniques to reduce the risk of complications. In order to reduce the rate of complications of CVCs it is indispensable to perform a risk-benefit analysis for the individual patient before every insertion. The type of catheter used (for example tunneled catheters versus not-tunneled catheters) influences the rate of catheter-associated infections and the comfort of the patient significantly. The choice of the location is influenced by the expected indwelling time, the weight of the patient and the purpose of the CVC. Insertion via the vena jugularis interna is often chosen because of the reduced rate of complications during insertion. When the planned indwelling time of the catheter is longer or the child is fairly small the vena subclavia appears to be more appropriate. It is of utmost importance that the patient is positioned properly before insertion. Whenever possible the insertion should be performed with the help of ultrasound. The positioning of the catheter should be verified radiographically, possibly sonographically or with an ECG in order to avoid misplacement with potentially severe sequelae. The locally established hygienic guidelines should be strictly adhered to and everyone handling CVCs (doctors, nurses and patients) should have regular training.

Risk factors for central line-associated bloodstream infection in pediatric oncology patients with a totally implantable venous access port: A cohort study

BACKGROUND

Totally implantable venous access ports (TIVAPs) are used for prolonged central venous access, allowing the infusion of chemotherapy and other fluids and improving the quality of life of children with cancer. TIVAPs were developed to reduce the infection rates associated with central venous catheters; however, infectious events remain common and have not been fully investigated in pediatric oncology patients.

PROCEDURE

A retrospective cohort was formed to investigate risk factors for central line-associated bloodstream infection (CLABSI) in pediatric cancer patients. Sociodemographic, clinical, and TIVAP insertion-related variables were evaluated, with the endpoint being the first CLABSI. A Kaplan-Meier analysis was performed to determine CLABSI-free catheter survival.

RESULTS

Overall, 188 children were evaluated over 77,541 catheter days, with 94 being diagnosed with CLABSI (50%). Although coagulase-negative staphylococci were the pathogens most commonly isolated, Gram-negative microorganisms (46.8%) were also prevalent. In the multivariate analysis, factors that increased the risk for CLABSI were TIVAP insertion prior to chemotherapy (risk ratio [RR] = 1.56; P < 0.01), white blood cell count less than 1,000 mm^-3 on the day of implantation (RR = 1.64; P < 0.01), and chronic malnutrition (RR = 1.41; P < 0.05). Median time without CLABSI following TIVAP insertion was 74.5 days.

CONCLUSIONS

Risk factors for CLABSI in pediatric cancer patients with a TIVAP may be related to the severity of the child's condition at catheter insertion. Insertion of the catheter before chemotherapy and unfavorable conditions such as malnutrition and bone marrow aplasia can increase the risk of CLABSI. Protocols must be revised and surveillance increased over the first 10 weeks of treatment.

The Impact of Central Venous Catheters on Pediatric Venous Thromboembolism

The use of central venous catheters (CVCs) in children is escalating, which is likely linked to the increased incidence of pediatric venous thromboembolism (VTE). In order to better understand the specific risk factors associated with CVC-VTE in children, as well as available prevention methods, a literature review was performed. The overall incidence of CVC-VTE was found to range from 0 to 74%, depending on the patient population, CVC type, imaging modality, and study design. Throughout the available literature, there was not a consistent determination regarding whether a particular type of central line (tunneled vs. non-tunneled vs. peripherally inserted vs. implanted), catheter material, insertion technique, or insertion location lead to an increased VTE risk. The patient populations who were found to be most at risk for CVC-VTE were those with cancer, congenital heart disease, gastrointestinal failure, systemic infection, intensive care unit admission, or involved in a trauma. Both mechanical and pharmacological prophylactic techniques have been shown to be successful in preventing VTE in adult patients, but studies in children have yet to be performed or are underpowered. In order to better determine true CVC-VTE risk factors and best preventative techniques, an increase in large, prospective pediatric trials needs to be performed.

Central Line Associated Blood Stream Infections in Pediatric Hematology/Oncology Patients With Different Types of Central Lines

BACKGROUND

Central line associated bloodstream infections (CLABSIs) are a significant cause of morbidity and mortality in pediatric hematology/oncology (PHO) patients. Understanding the differences in CLABSI rates by central line (CL) type is important to inform clinical decisions.

PROCEDURE

CLABSI, using similar definitions, noted with three commonly used CL types (totally implanted catheter [port], tunneled externalized catheter [TEC], peripherally inserted central catheter [PICC]) and CL-specific line days were prospectively tracked across 15 US PHO centers from May 2012 until April 2015 and CLABSI rates (CLABSI per 1,000 CL-specific line days) were calculated. Host and organism characterstics associated with the CLABSI events were analyzed.

RESULTS

Over the course of 2.8 million line days, 1,113 CLABSI events (397 in inpatients and 716 in ambulatory patients) were noted. The inpatient CLABSI rate was higher than the ambulatory CLABSI rate for each of the CL types: 1.48 versus 0.16 for ports, 3.51 versus 1.38 for TECs, and 3.07 versus 1.16 for PICCs, respectively. TECs and PICCs were associated with higher CLABSI rates than ports, inpatient and ambulatory.

CONCLUSIONS

We found that CLABSI rates were significantly higher for inpatients compared to ambulatory PHO patients for all CL types. Among ambulatory patients, TECs had the highest CLABSI rate and ports the lowest. Among inpatients, TECs and PICCs had higher CLABSI rates than ports but were not statistically different from one another. Cognizant that host and underlying disease attributes may contribute to these differences, these results can still inform CL choice in clinical practice.

Strategies to Prevent and Manage Thrombotic Complications of Acute Lymphoblastic Leukemia in Children and Young People Vary Between Centers in the United Kingdom

There is a lack of evidence-based guidance for the prevention and management of thrombosis in children and young people treated for acute lymphoblastic leukemia. To determine current UK practice, a survey was sent to 28 centers participating in the Medical Research Council UKALL 2011 trial. Marked variation in practice was noted. In total, 43% of centers defer central venous access device insertion until end of induction for treatment of low-risk disease. Central venous access devices are removed at the end of intensive blocks in 38% and end of treatment in 42%. Duration of anticoagulation for line-associated thrombosis is 6 weeks in 43% and 3 months in 33% and for cerebral sinovenous thrombosis is 3 months in 71% and 6 months in 24%. Platelet transfusion to maintain platelet count >50×10/L, in preference to interrupting therapeutic anticoagulation, is used by 50% for line-associated thrombosis and 73% for cerebral sinovenous thrombosis. Conformity of practice was seen in some areas. In total, 70% treat thrombosis with twice-daily low-molecular weight heparin and 86% monitor antifactor Xa activity levels. In total, 91% reexpose individuals to asparaginase following a thrombotic event. Given this variation in practice, in the absence of high-quality evidence, consensus guidelines may be helpful.

Complications of Central Venous Access Devices: A Systematic Review

CONTEXT

The failure and complications of central venous access devices (CVADs) result in interrupted medical treatment, morbidity, and mortality for the patient. The resulting insertion of a new CVAD further contributes to risk and consumes extra resources.

OBJECTIVE

To systematically review existing evidence of the incidence of CVAD failure and complications across CVAD types within pediatrics.

DATA SOURCES

Central Register of Controlled Trials, PubMed, and Cumulative Index to Nursing and Allied Health databases were systematically searched up to January 2015.

STUDY SELECTION

Included studies were of cohort design and examined the incidence of CVAD failure and complications across CVAD type in pediatrics within the last 10 years. CVAD failure was defined as CVAD loss of function before the completion of necessary treatment, and complications were defined as CVAD-associated bloodstream infection, CVAD local infection, dislodgement, occlusion, thrombosis, and breakage.

DATA EXTRACTION

Data were independently extracted and critiqued for quality by 2 authors.

RESULTS

Seventy-four cohort studies met the inclusion criteria, with mixed quality of reporting and methods. Overall, 25% of CVADs failed before completion of therapy (95% confidence interval [CI] 20.9%-29.2%) at a rate of 1.97 per 1000 catheter days (95% CI 1.71-2.23). The failure per CVAD device was highest proportionally in hemodialysis catheters (46.4% [95% CI 29.6%-63.6%]) and per 1000 catheter days in umbilical catheters (28.6 per 1000 catheter days [95% CI 17.4-39.8]). Totally implanted devices had the lowest rate of failure per 1000 catheter days (0.15 [95% CI 0.09-0.20]).

LIMITATIONS

The inclusion of nonrandomized and noncomparator studies may have affected the robustness of the research.

CONCLUSIONS

CVAD failure and complications in pediatrics are a significant burden on the health care system internationally.

F. Development and validation of a prediction model for diagnosing blood stream infections in febrile, non-neutropenic children with cancer

BACKGROUND

Pediatric oncology patients are at increased risk for blood stream infections (BSI). Risk in the absence of severe neutropenia (absolute neutrophil count [ANC] ≥500/µl) is not well defined.

PROCEDURE

In a retrospective cohort of febrile (temperature ≥38.0° for >1 hr or ≥38.3°) pediatric oncology patients with ANC ≥500/µl, a diagnostic prediction model for BSI was constructed using logistic regression modeling and the following candidate predictors: age, ANC, absolute monocyte count, body temperature, inpatient/outpatient presentation, sex, central venous catheter type, hypotension, chills, cancer diagnosis, stem cell transplant, upper respiratory symptoms, and exposure to cytarabine, anti-thymocyte globulin, or anti-GD2 antibody. The model was internally validated with bootstrapping methods.

RESULTS

Among 932 febrile episodes in 463 patients, we identified 91 cases of BSI. Independently significant predictors for BSI were higher body temperature (Odds ratio [OR] 2.36 P < 0.001), tunneled external catheter (OR 13.79 P < 0.001), peripherally inserted central catheter (OR 3.95 P = 0.005), elevated ANC (OR 1.19 P = 0.024), chills (OR 2.09 P = 0.031), and hypotension (OR 3.08 P = 0.004). Acute lymphoblastic leukemia diagnosis (OR 0.34 P = 0.026), increased age (OR 0.70 P = 0.049), and drug exposure (OR 0.08 P < 0.001) were associated with decreased risk for BSI. The risk prediction model had a C-index of 0.898; after bootstrapping adjustment for optimism, corrected C-index 0.885.

CONCLUSIONS

We developed a diagnostic prediction model for BSI in febrile pediatric oncology patients without severe neutropenia. External validation is warranted before use in clinical practice. Pediatr Blood Cancer 2015;62:262-268. © 2014 Wiley Periodicals, Inc.

The association of central venous catheter placement timing with infection rates in patients with acute leukemia

BACKGROUND

Timing of central venous catheter (CVC) insertion among patients with acute leukemia is debatable. Early insertion increases convenience, but might increase infection rates.

METHODS

We assessed retrospectively the rate of central line-associated bloodstream infections (CLABSI) according to CVC time of insertion in patients with acute leukemia admitted for induction or salvage therapy. The study was conducted in the Hematology Department of a Tertiary hospital in Israel between 2007 and 2011. Early CVC placement was defined as CVC inserted during the first week of induction therapy. CLABSI rate was documented between the seventh day of induction therapy to 30 days after its completion.

RESULTS

A total of 127 patients were included. Acute myeloid leukemia was the most common diagnosis (103 patients, 80.5%). Late CVC placement was associated with CLABSI after adjustment to the Charlson comorbidity index (OR 3.4, 95% CI 1.1-10.45), p=0.03.

CONCLUSION

Delaying CVC placement in adult patients with acute leukemia may be associated with higher rate of CLABSI in the early period after induction therapy.

Low molecular weight heparin for prevention of central venous catheterization-related thrombosis in children

BACKGROUND

The prevalence of children diagnosed with deep vein thrombosis or pulmonary embolism has been increasing in the last decade. The most common thrombosis risk factor in neonates, infants and children is the placement of a central venous catheter (CVC). To date, it is unknown if the practice of anticoagulation prophylaxis with low molecular weight heparin (LMWH) decreases CVC-related thrombosis in children.

OBJECTIVES

The primary objective of this review was to determine the effect of LMWH prophylaxis on reducing the incidence of CVC-related thrombosis in children.Secondary objectives were to determine the effect of LMWH on occlusion of CVCs, number of days of CVC patency, episodes of catheter-related sepsis, side effects of LMWH (allergic reactions, major and minor bleeding complications, abnormal coagulation profile, osteoporosis) and mortality during therapy.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched June 2013), CENTRAL (2013, Issue 5) and clinical trial databases. The authors searched MEDLINE and EMBASE (July 2013). Bibliographies of identified articles were searched. There were no language restrictions.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing LMWH prophylaxis to standard care given to prevent CVC-related thrombotic events in children were included. We selected studies conducted in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified eligible studies, which were assessed for study quality including bias, and extracted unadjusted data where available. In the data analysis step, all outcomes were analysed as binary or dichotomous outcomes. The effects of interventions were summarised with risk ratios (RR) and their respective 95% confidence intervals (CI).

MAIN RESULTS

One of 17 studies retrieved for full-text assessment for eligibility was included in the final analysis. This study included a total of 186 participants and investigated the effect of LMWH to prevent CVC-related thrombosis compared to standard care. The risk of bias of the study was assessed to be low, except for the unclear risk of selection bias (allocation concealment not reported) and detection bias since it was an open-label study. Nonetheless, outcome adjudication was blinded. However, overall the quality of the evidence was low due to the fact that the study was underpowered. The CIs for the risk of CVC-related thrombosis (symptomatic and asymptomatic events) were compatible with benefits of either LMWH (reviparin) or the control (RR for symptomatic thrombosis 1.03, 95% CI 0.21 to 4.93; RR for asymptomatic thrombosis 1.17, 95% CI 0.45 to 3.08). Similarly, only one patient in the standard care group suffered a major bleeding event, while minor bleeding was found in 53.3% of patients in the reviparin arm and in 44.7% of patients in the standard care arm (major bleeding RR 0.34, 95% CI 0.01 to 8.26; minor bleeding RR 1.20, 95% CI 0.91 to 1.58). Lastly, there were two deaths within the study and neither were the result of a venous thrombotic event (VTE), occurring in the standard care arm. No additional adverse effects were reported. Other pre-specified outcomes for this review were not reported.

AUTHORS' CONCLUSIONS

A single study reported imprecise effects for the risk of CVC-related thrombosis in children on a CVC anticoagulant prophylaxis regimen. The quality of the evidence was low due to the fact that the included study was clearly underpowered, hampering any conclusions in regards to the efficacy of LMWH prophylaxis to prevent CVC-related thrombi in children. Further prospective randomised studies are highly encouraged.

Infectious morbidity by catheter type in neutropenic children with cancer

BACKGROUND

Three central venous catheters types are commonly used in pediatric cancer: totally implantable catheters (ICs; eg, mediports, portacaths), tunneled externalized catheters (eg Broviac® or Hickman® catheters [Bard Medical]) and peripherally inserted central catheters. While previous studies have examined risks for catheter-related infections, this is the first large multicenter study to compare catheter-associated infectious morbidity through patient outcomes and hospital utilization.

METHODS

A historical cohort analysis was conducted using data from the Pediatric Health Information System reporting 1167 hospitalizations of neutropenic patients with childhood cancer and a central venous catheters. Multivariate analyses controlled for age, ethnicity, gender, malignancy category and transplant status. Outcomes included incidence of serious bacterial infection, mortality, duration of hospitalization, time and use of intensive care unit and antibiotic usage.

RESULTS

Neutropenic cancer patients with totally ICs (n = 429) have a statistically significant approximately 50% decrease in length of hospitalization (P < 0.001), risk for requiring an intensive care unit stay (P = 0.002), documented serious bacterial infection (P = 0.001) and days on antibiotics (P < 0.001) when compared with patients with tunneled externalized catheters (n = 463). Similar differences were found comparing hospitalizations of patients with ICs to those with peripherally inserted central catheters (n = 275). No difference in mortality was observed among catheters groups.

CONCLUSIONS

In neutropenic pediatric oncology patients with a central venous catheters, ICs are associated with the least hospital utilization including shortest duration of hospitalization, intensive care unit time and antibiotic therapy when compared with tunneled external catheters and peripherally inserted central catheters. The impact of differences in catheter-associated infectious morbidity on patient outcomes and hospital utilization should be included in clinical decision making.

A comparison of central lines in pediatric oncology patients: Early removal and patient centered outcomes

BACKGROUND

While there is increasing evidence supporting the choice of subcutaneous ports (SPs) over external venous catheters (EVCs) in pediatric oncology patients, prior conflicting studies exist and little data have been gathered as to which type of central line is preferred from the patient/family perspective.

PROCEDURE

We performed a single institution, 10 years, retrospective analysis of central lines in pediatric oncology patients (n = 878) to evaluate unplanned early removal and cause of removal while simultaneously obtaining a cross sectional survey of 143 of the primary caretakers/parents of these patients to evaluate their overall satisfaction with the line.

RESULTS

EVCs have significantly higher odds of unplanned early removal in comparison to SPs (6.7% of SPs vs. 27.3% of EVCs, odds ratio (OR) = 6.3, P < 0.0001 when controlling for age and diagnosis) secondary to increased infection, malfunction and patient preference. Patients with SPs felt like their central line was easier to care for, had less daily impact in their life, and were overall more satisfied with their central line compared to patients with EVCs, even when controlling for early removal (P < 0.0001 for all). SP patients were much more likely to state that they would choose the same type of line again (OR = 15, P < 0.0001) than EVC patients.

CONCLUSION

SPs demonstrated lower removal rates and greater patient satisfaction than EVCs. These data should be considered when choosing a central line for pediatric cancer patients.

Venous access catheter-related thrombosis in patients with cancer

Patients with cancer are at high risk for developing venous thromboembolism (VTE), and the presence of a central venous catheter (CVC) further increases this risk. CVC-related VTE has serious implications related to the loss of vascular access, development of pulmonary embolism, recurrent VTE, infections and post-thrombotic syndrome. The pathogenesis of CVC-related VTE is complex and multifactorial, with risk factors associated with the catheter, the vessel selected for insertion and the underlying cancer as well as the anti-cancer therapy. Clinical presentation of CVC-related VTEs is often non-specific, and ultrasonography is the most commonly used radiological diagnostic test. Management of CVC-related VTE in patients with cancer requires a balance between the need for venous access, the risk of VTE recurrence and the risk of bleeding from treatment-induced thrombocytopenia. Effective VTE prophylaxis methods have yet to be defined. Ongoing studies are evaluating the role of newer oral antithrombotic agents and alternative interventional strategies for the prevention and treatment of CVC-related VTE in patients with cancer.

Prospective surveillance study of blood stream infections associated with central venous access devices (port-type) in children with acute leukemia: an intervention program

The use of intensive chemotherapy and central devices has improved patients survival, but it is associated with catheter-related blood-stream infections (CRBSI). An educational program was instituted for preventing CRBSI occurrence in acute leukemia pediatric patients having totally implanted central devices. The Centers of Disease Control and Prevention criteria were used as definition for CRBSI. Data collected were age, sex, diagnosis, chemotherapy, inpatient versus outpatient, microbiological data, risk factors, social risk score, and treatment performed. CRBSI rate decreased from 6.7 to 3.7/1000 catheter-days with preventive measures (P=0.05). A further decrease to 1.5/1000 catheter-days was reached after the intensification of the educational program (P=0.01). Severe neutropenia at the time of catheter insertion was related to CRBSI and to infection recurrence (P<0.05). Most of the episodes occurred during induction chemotherapy. Thirty-six CRBSI episodes occurred in 25 of 73 patients. The most frequent microorganism isolated was Staphylococcus spp. Antibiotherapy was successful in 83.3% of episodes. Six patients needed a central venous access device replacement. Our intervention program was successful to decrease the CRBSI rates and its intensification allowed a further decrease, approaching reported rates in this setting. Severe neutropenia at the time of central venous access device insertion was related to CRBSI occurrence and recurrence.

Catheter-associated bloodstream infections in pediatric hematology-oncology patients

Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen.

Rapid reduction of central line infections in hospitalized pediatric oncology patients through simple quality improvement methods

BACKGROUND

Pediatric hematology-oncology (PHO) patients are at significant risk for developing central line-associated bloodstream infections (CLA-BSIs) due to their prolonged dependence on such catheters. Effective strategies to eliminate these preventable infections are urgently needed. In this study, we investigated the implementation of bundled central line maintenance practices and their effect on hospital-acquired CLA-BSIs.

MATERIALS AND METHODS

CLA-BSI rates were analyzed within a single-institution's PHO unit between January 2005 and June 2011. In May 2008, a multidisciplinary quality improvement team developed techniques to improve the PHO unit's safety culture and implemented the use of catheter maintenance practices tailored to PHO patients. Data analysis was performed using time-series methods to evaluate the pre- and post-intervention effect of the practice changes.

RESULTS

The pre-intervention CLA-BSI incidence was 2.92 per 1,000-patient days (PD) and coagulase-negative Staphylococcus was the most prevalent pathogen (29%). In the post-intervention period, the CLA-BSI rate decreased substantially (45%) to 1.61 per 1,000-PD (P < 0.004). Early on, blood and marrow transplant (BMT) patients had a threefold higher CLA-BSI rate compared to non-BMT patients (P < 0.033). With additional infection control countermeasures added to the bundled practices, BMT patients experienced a larger CLA-BSI rate reduction such that BMT and non-BMT CLA-BSI rates were not significantly different post-intervention.

CONCLUSIONS

By adopting and effectively implementing uniform maintenance catheter care practices, learning multidisciplinary teamwork, and promoting a culture of patient safety, the CLA-BSI incidence in our study population was significantly reduced and maintained.

International clinical practice guidelines for the treatment and prophylaxis of thrombosis associated with central venous catheters in patients with cancer

BACKGROUND

Although long-term indwelling central venous catheters (CVCs) may lead to pulmonary embolism (PE) and loss of the CVC, there is lack of consensus on management of CVC-related thrombosis (CRT) in cancer patients and heterogeneity in clinical practices worldwide.

OBJECTIVES

To establish common international Good Clinical Practices Guidelines (GCPG) for the management of CRT in cancer patients.

METHODS

An international working group of experts was set up to develop GCPG according to an evidence-based medicine approach, using the GRADE system.

RESULTS

For the treatment of established CRT in cancer patients, we found no prospective randomized studies, two non-randomized prospective studies and one retrospective study examining the efficacy and safety of low-molecular-weight heparin (LMWH) plus vitamin K antagonists (VKAs). One retrospective study evaluated the benefit of CVC removal and two small retrospective studies were on thrombolytic drugs. For the treatment of symptomatic CRT, anticoagulant treatment (AC) is recommended for a minimum of 3 months; in this setting, LMWHs are suggested. VKAs can also be used, in the absence of direct comparisons of these two types of anticoagulants in this setting [Guidance]. The CVC can be kept in place if it is functional, well-positioned and non-infected and there is good resolution under close surveillance; whether the CVC is kept or removed, no standard approach in terms of AC duration has been established [Guidance]. For the prophylaxis of CRT in cancer patients, we found six randomized studies investigating the efficacy and safety of VKA vs. placebo or no treatment, one on the efficacy and safety of unfractionnated heparin, six on the value of LMWH, one double-blind randomized and one non randomized study on thrombolytic drugs and six meta-analyses of AC and CVC thromboprophylaxis. Type of catheter (open-ended like the Hickman(®) catheter vs. closed-ended catheter with a valve like the Groshong(®) catheter), its position (above, below or at the junction of the superior vena cava and the right atrium) and method of placement may influence the onset of CRT on the basis of six retrospective trials, four prospective non-randomized trials, three randomized trials and one meta-analysis. In light of these data: use of AC for routine prophylaxis of CRT is not recommended [1A]; a CVC should be inserted on the right side, in the jugular vein, and distal extremity of the CVC should be located at the junction of the superior vena cava and the right atrium [1A].

CONCLUSION

Dissemination and implementation of these international GCPG for the prevention and treatment of CRT in cancer patients at each national level is a major public health priority, needing worldwide collaboration.

Implantable versus cuffed external central venous catheters for the management of children and adolescents with acute lymphoblastic leukaemia

PURPOSE

The aim of this study was to determine if there is a difference between complications for totally implantable central venous catheters (ports) and tunnelled external central venous catheters (external CVCs) that result in early removal of the central venous catheter (CVC) in children and adolescents with acute lymphoblastic leukaemia (ALL).

METHODS

All children hospitalised between November 1996 and December 2007 with ALL who had a CVC were included retrospectively. We analysed data regarding the patient's first CVC.

RESULTS

We included 322 patients. 254 received a port and 68 received an external CVC. There were 102 CVC complications that required removal of the CVC prior to the completion of chemotherapy (65 in patients with ports, 37 in patients with external CVCs). Overall complications requiring CVC removal were significantly less likely to occur in the patient's with ports (p < 0.001). Ports were significantly less likely to require removal prior to the end of treatment overall (p < 0.001) and for specific complications such as infection (p < 0.001) and dislodgement (p = 0.001). However, when adjusted for disease severity there is no difference in premature CVC removal rates.

CONCLUSION

When patients are risk-stratified for disease severity there is no difference in rates of CVC removal prior to completion of treatment.

The coagulopathy and thrombotic risk associated with L-asparaginase treatment in adults with acute lymphoblastic leukaemia

The dramatic improvements seen in the outcome of paediatric patients with acute lymphoblastic leukaemia (ALL) have led to increasing incorporation of L-asparaginase (L-Asp) in adult treatment protocols. However, its use is associated with a disruption in the physiological balance between haemostatic and anticoagulant pathways, with the predominant clinical manifestation being thrombosis. Although L-Asp therapy is known to be associated with an acquired deficiency of antithrombin (AT), the concurrent depletion of fibrinogen and other haemostatic proteins means that the precise mechanism of thrombosis remains to be defined. In vitro coagulation assays are often prolonged but thrombosis rather than haemorrhage is the primary concern. Management of thrombotic events in these patients is based around agents that rely on AT for their anticoagulant effect, even though it is usually depleted. There is currently only limited evidence supporting the use of AT concentrates in either primary prevention or management following an established event. Evidence-based guidelines for prevention and management strategies are lacking.

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.

Thrombotic disease in critically ill children

OBJECTIVES

To summarize a) epidemiology of arterial and venous thromboembolism, pulmonary embolism, and deep venous thrombosis in children; b) the risk factors for thrombosis in the pediatric intensive care unit; c) diagnostic techniques for arterial/venous thromboembolism; and d) the current recommendations for management and prevention of thromboembolic disease in critically ill children.

DATA SOURCE

Literature review, using National Library of Medicine PubMed and the following terms: arterial, venous thromboembolism; deep venous thrombosis; pulmonary embolism; thrombosis; as well as citations of interest from these articles.

STUDY SELECTION

Both pediatric and adult literature addressing thrombotic disease were reviewed.

DATA EXTRACTION AND SYNTHESIS

Articles were chosen for more extensive discussion when containing prospective studies, guidelines for practice, or data in critically ill patients. When data in children were unavailable, applicable data in adults were referenced. Due to the paucity of data in critically ill children, available adult and pediatric data were combined with institutional experience to provide suggestions for current practice and future inquiry.

CONCLUSIONS

Increasing awareness regarding the recognition and current approaches to management and prevention of thromboembolic disease in children is needed among pediatric intensivists, so outcome of these life-threatening processes might be improved.

Severe neutropenia at time of port insertion is not a risk factor for catheter-associated infections in children with acute lymphoblastic leukemia

BACKGROUND

The objective of this study was to determine whether severe neutropenia on the day of port-a-catheter (PORT) insertion was a risk factor for catheter-associated infection (CAI) in children with acute lymphoblastic leukemia (ALL).

METHODS

This was a retrospective study of children with ALL who had a PORT insertion between January 2005 and August 2008. Early (≤ 30 days) and late (>30 days) postprocedure complications were reviewed. The length of follow-up ranged between 7 months and 42 months.

RESULTS

In total, 192 PORTs were inserted in 179 children. There were 43 CAIs (22%), and the infection rate was 0.35 per 1000 catheter-days. The CAI rate (15%) in children who had severe neutropenia on the day of the procedure did not differ statistically from the CAI rate (24%) in children who did not have severe neutropenia (P = .137). Conversely, patients with severe neutropenia who had a CAI were more likely to have their PORT removed (P = .019). The most common organisms to cause catheter removal were coagulase-negative Staphylococcus and Staphylococcus aureus. Patients with high-risk ALL had a statistically significant higher incidence of late CAI than patients with standard-risk ALL (P = .012). Age (P = .272), positive blood culture preprocedure (P = 1.0), and dexamethasone use (P = .201) were not risk factors for CAI. Patients who had an early CAI did not have a greater chance of having a late CAI. The catheter infection-free survival rate at 1 year was 88.6%.

CONCLUSIONS

The current results indicated that severe neutropenia on the day of PORT insertion does not increase the risk of CAI in children with ALL.

Placing of tunneled central venous catheters prior to induction chemotherapy in children with acute lymphoblastic leukemia

BACKGROUND

Tunneled central venous catheters (CVCs) are inevitable in children with acute lymphoid leukemia (ALL). The aim of this study was to evaluate the risk of CVC-related complications in children with ALL in relation to timing of catheter placement and type of catheter.

PROCEDURE

All children hospitalized from January 2000 to March 2008 with newly diagnosed ALL and with double-lumen total implantable devices (TIDs) or tunneled external catheters (TEs) were included retrospectively. We only used data related to the patient's first catheter.

RESULTS

We included 98 children; 35 received a TID and the remaining 63 received a TE. A total number of 29,566 catheter days and 93 catheter-associated blood stream infections (CABSI) was identified. We found a CABSI rate of 3.1/1,000 catheter days (5.4/1,000 catheter days for TEs and 1.4/1,000 catheter days for TIDs, incidence rate ratio (IRR) 3.82 (95% CI 2.37-6.35) P = 0.0001). No difference was found in CABSI between neither early versus later placed TIDs (IRR = 0.99 (95% CI 0.41-2.45) P = 0.98) nor early versus later placed TEs (IRR = 0.81 (95% CI 0.40-1.86) P = 0.54). We found no difference between early and later placed catheters regarding non-elective removal (RR = 0.86 (95% CI 0.72-1.03) P = 0.09). TEs had a higher risk of non-elective removal compared with TIDs (RR = 3.95 (95% CI 1.88-8.29) P < 0.001).

CONCLUSIONS

The study did not find that children with ALL and with early placed CVCs experienced significantly more complications compared with children with late placed catheters. This study found that children with ALL and TEs experienced more complications than children with TIDs.

Groshong catheter-related complications in children with cancer

BACKGROUND

Children with cancer undergo intensive treatments requiring reliable vascular access. Central venous catheters (CVCs) reduce discomfort due to venipuncture and the risks of extravasations from chemotherapy administration. The aim of our retrospective study was to assess safety and complications of Groshong devices in children with cancer.

PATIENTS AND METHODS

One hundred ninety Groshong CVCs were placed in 166 children over a 5-year period. Early complications, and infectious and mechanical events were collected.

RESULTS

The mean period of permanence of the CVCs was 330 days per patient (range 7-1,037). Of the febrile episodes, 36 (34.6%) were CVC-related, with an incidence rate of 0.56 per 1,000 CVC days. Severe neutropenia conditions most of all complicated CVC-related infectious events (94.4%) and Gram-negative bacteria were those most often isolated (55%). Twenty CVCs were affected by mechanical or thrombotic complications, with an incidence of 0.33 episodes per 1,000 CVC days. Mechanical complications led to CVC removal in 6 (3.1%) cases, while CVC-related infective episodes were responsible for 10 (5.2%) CVC removals.

CONCLUSIONS

The long in situ duration of this device allowed it to be safely employed from the beginning to the end of the treatment period in most children.

Exclusion of neutropenic children from implanted central venous catheter placement: impact on early catheter removal

BACKGROUND/PURPOSE

Based on the known risks of implanted central venous catheter (ICVC) placement in neutropenic children, we instituted a protocol whereby children with hematologic malignancies and an absolute neutrophil count less than 0.5 x 10(9)/L were excluded from an ICVC and had a percutaneously inserted central catheter placed until neutropenia resolved. The impact of this policy on the incidence of ICVC removal within 100 days of placement was evaluated.

METHODS

The records of all children with hematologic malignancies who underwent placement of an ICVC (port or cuffed catheter) from 1999 through 2008 were reviewed. The incidence of catheter removal within 100 days was compared between subjects who had ICVC placed before (preprotocol) and after (postprotocol) the absolute neutrophil count-based exclusion protocol.

RESULTS

Implanted central venous catheters were placed in 437 children, 311 in group 1 and 126 in group 2. The incidence of catheter removal within 100 days of placement for infection (4.1% [13/314] versus 0.8% [1/126], P = .07) and all causes combined (9.6% [30/314] versus 2.4% [3/126], P = .01) was substantially lower in the postprotocol group.

CONCLUSIONS

We have demonstrated that a protocol whereby neutropenic children were excluded from ICVC placement dramatically diminished complications that necessitated early catheter removal.

Bacteremia in febrile nonneutropenic pediatric oncology patients

BACKGROUND

We sought to determine the risk of bacteremia in a cohort of outpatient febrile nonneutropenic pediatric oncology patients and to assess clinical characteristics that may influence decisions regarding empiric antibiotic therapy.

PROCEDURE

A single institution retrospective cohort study was performed of outpatient pediatric oncology patients presenting with fever, a central venous catheter, and an absolute neutrophil count (ANC) of >/=500/microl over a 6-year period. We also collected data regarding the presence of clinically evident infections, antibiotics prescribed, and the sensitivity of bacteria to specific antibiotics.

RESULTS

There were 29 cases of bacteremia in 459 (6.3%) febrile outpatient visits by 167 patients. Bacteremia was documented in 4.4% of patients with ports and in 16.2% of patients with external catheters. Patients with external catheters had a relative risk of bacteremia of 3.7 (95% CI: 1.8-7.4) times the risk of those with internal catheters (P < 0.0001). A documented source for fever on exam was noted in 21% of patients but in none of the patients with bacteremia (P = 0.004). Empiric treatment with ceftriaxone was administered to 92% of the patients. Of the high-risk bacteremic infections (Gram-negative organisms, Streptococcus pneumoniae, viridans group streptococcus, and Staphylococcus aureus) 94% had at least an intermediate sensitivity to ceftriaxone.

CONCLUSIONS

Bacteremia is an important issue in febrile nonneutropenic pediatric oncology patients occurring in 6% of the patient visits in this study. The overall sensitivity of high-risk bacteremia to ceftriaxone provides justification for its empiric use in outpatient febrile nonneutropenic pediatric oncology patients.

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.