Malfunctioning central venous catheters in children: a diagnostic approach

Central venous access device adverse events in pediatric patients with cancer: a systematic review and meta-analysis

PURPOSE

To systematically review the proportion and incidence of CVAD-associated complications in pediatric patients with cancer.

METHODS

PubMed, Embase, and the Cumulative Index of Nursing and Allied Health Literature were searched from 2012 to 2022. Cohort studies and the control arm of randomized controlled trials, which reported CVAD-associated complications in pediatric patients aged 0-18 years, were included. CVAD complications were defined as CVAD failure, central line-associated bloodstream infection (CLABSI), local infection, occlusion, CVAD-associated venous thromboembolism, dislodgement/migration, breakage/rupture, and dehiscence. The pooled proportion and incidence rate (IR) for each CVAD-associated complication were reported.

RESULTS

Of 40 included studies, there was mixed quality of methods and reporting. Approximately 31.4% (95% confidence interval [CI] 22.5-41.1; 6920 devices) of devices experienced a CVAD-associated complication, and 14.8% (95% CI 10.2-20.1; 24 studies; 11,762 devices) of CVADs failed before treatment completion (incidence rate (IR) of 0.5 per 1000 catheter days (95% CI 0.3-0.8; 12 studies; 798,000 catheter days)). Overall, 21.2% (95% CI 14.3-28.9; 26 studies; 5054 devices) of CVADs developed a CLABSI, with an IR of 0.9 per 1000 catheter days (95% CI 0.6-1.3; 12 studies; 798,094 catheter days). Tunneled central venous catheters (TCVC) and peripherally inserted central catheters (PICCs) were associated with increased complications in comparison to totally implanted venous access devices (TIVADs).

CONCLUSION

CVAD complication rates in this population remain high. TCVCs and PICCs are associated with increased complications relative to TIVADs. Insufficient evidence exists to guide device selection in this cohort, necessitating further research to determine the role of PICCs in pediatric cancer care.

PROSPERO

CRD42022359467. Date of registration: 22 September 2022.

Life on the line - Incidence and management of central venous catheter complications in intestinal failure

BACKGROUND & AIMS

Loss of venous access is threatening for patients with intestinal failure (IF) under long-term parenteral nutrition (PN). We aimed to identify the incidence of central venous catheter (CVC) complications, compare different devices, and analyze interventional recanalizing procedures to restore the patency of occluded CVCs.

METHODS

For this retrospective cohort study, patient data from a prospective IF database spanning 16 years was analyzed at a tertiary referral center. Catheter dwell times (CDTs) were distinguished by Kaplan-Meier survival analysis and subgroup analyses were performed for different CVC types (tunneled/port catheters). Specific complications (occlusion, catheter-related infection (CRI), displacement, and material defect) were analyzed. Explantation rates and CDTs were compared.

RESULTS

Overall, 193 CVCs in 77 patients with IF under PN could be enrolled (62.524 "CVC-days"). Broviac type "B" was found to be significantly superior to type "A" regarding occlusion, CRI, and material defects (log-rank test: p = 0.05; p = 0.026; p = 0.005 respectively). Port catheters were displaying the highest incidence of CRI (2.13 events/1000 catheter days). Interventional catheter recanalization was performed 91 times and significantly increased the CDT from a median of 131 days (IQR: 62; 258) to 389 days (IQR: 262; 731) (Mann-Whitney-U-test: p= <0.001) without increasing complications.

CONCLUSIONS

Different complication rates and CDT were seen depending on CVC type. Tunneled catheters were significantly superior concerning CRI. Interventional catheter recanalization is a viable alternative to fibrinolytics to restore CVC patency, but long-term patency data is scarce.

Removal of central venous catheter using Evolution® Rotating Dilator

We experienced the first case of a difficult-to-extract central venous catheter removed with a pacemaker lead removal system: a 14-year-old boy with Hirschsprung's disease who had repeated catheter infections that could not be removed by traction. Because the catheter lumen was occluded, a suture was tied around the end of the catheter and the catheter was removed with a rotating dilator.

Diagnostic challenges with central venous catheter studies

A central venous catheter is typically made of silicone rubber or polyurethane and inserted into a large central vein to provide prolonged and direct access to central venous circulation. These catheters provide a safe and effective method to administer intravenous medications, nutritional supplements, fluids and blood products. However, a myriad of complications is associated with central venous catheters, including, but not limited to, mechanical malfunction or fracture, kinking, erroneous placement, line infection, fibrin sheath formation and venous thrombosis. Following clinical and radiographic evaluation, contrast-enhanced line studies constitute the next best diagnostic tool to assess the functionality of central venous catheters. However, there is a lack of standardization in the literature outlining how these studies should be performed. In addition, the interpretation of these studies can be problematic for general pediatric radiologists, many of whom are often not familiar with placement or manipulation of these catheters. In this pictorial review, we highlight the challenges associated with performing and interpreting fluoroscopically guided contrast injection studies, using case studies drawn from a large tertiary children's hospital database for illustration. Revealing these challenges and understanding their causative mechanisms can improve the performance of these line studies.

CT and Sonographic Findings of a Calcified Fibrin Sheath From an Umbilical Venous Catheter in a Neonate

Central venous catheters are ubiquitous in current medical practice in intensive care units and for long-term nutrition, chemotherapy, and antibiotic therapies. Umbilical venous catheters provide short-term central vascular access and are used in the neonatal period. This case presents sonographic and CT imaging findings of an intrahepatic and intracardiac calcified fibrin sheath following removal of a short-term umbilical venous catheter in a 32-day-old premature neonate.

Computational investigation of the haemodynamics shows criticalities of central venous lines used for chronic haemodialysis in children

BACKGROUND

Haemodialysis is a life-saving treatment for children with kidney failure. The majority of children have haemodialysis through central venous lines (CVLs). The use of CVLs in pediatric patients is often associated to complications which can lead to their replacement. The aim of this study is to investigate haemodynamics of pediatric CVLs to highlight the criticalities of different line designs.

METHODS

Four models of CVLs for pediatric use were included in this study. The selected devices varied in terms of design and sizes (from 6.5 Fr to 14 Fr). Accurate 3D models of CVLs were reconstructed from high-resolution images including venous and arterial lumens, tips and side holes. Computational fluid dynamics (CFD) analyses were carried out to simulate pediatric working conditions of CVLs in ideal and anatomically relevant conditions.

RESULTS

The arterial lumens of all tested CVLs showed the most critical conditions with the majority of blood flowing through the side-holes. A zone of low flow was identified at the lines' tip. The highest shear stresses distribution (>10 Pa) was found in the 8 Fr line while the highest platelet lysis index in the 10 Fr model. The analysis on the anatomical geometry showed an increase in wall shear stress measured in the 10 F model compared to the idealised configuration. Similarly, in anatomical models an increased disturbance and velocity of the flow was found inside the vein after line placement.

CONCLUSION

This study provided a numerical characterization of fluid dynamics in pediatric CVLs highlighting performance criticalities (i.e. high shear stresses and areas of stagnation) associated to specific sizes (8 Fr and 10 Fr) and conditions (i.e. anatomical test).

Use of Tissue Plasminogen Activator as a Surrogate Measure for Central Venous Catheter Dysfunction and Survival Outcome in Children with Cancer: A Population-Based Retrospective Cohort Study

Central venous catheter (CVC) dysfunction is often associated with thrombosis, which in turn has been linked with poorer survival outcomes in cancer patients. Our objective was to examine the association of tissue plasminogen activator (tPA) administration as a surrogate measure of CVC dysfunction with survival in pediatric cancer patients. The present study uses data from a population-based retrospective cohort of pediatric oncology patients from the Canadian Maritime provinces treated between 2000 and 2017 at the IWK Health Centre, Halifax, NS. Demographics, diagnosis, date of death or date of last visit, and tPA use for CVC dysfunction were obtained from clinical databases and the provincial Cancer in Young People in Canada registry. The association between tPA administration and survival was examined using a Cox regression model adjusted for sex, age at diagnosis, cancer type, thrombosis, CVC duration, diagnosis era, and treatment modalities. Out of 821 patients, 206 received one or more doses of tPA during upfront therapy. The death rate was 21% and 15% respectively in patients who did and did not receive tPA. In the adjusted regression model, after receiving one or more doses of tPA, children had significantly poorer survival as compared to those that did not receive tPA (HR: 1.496, 95% CI: 1.019, 2.197). CVC dysfunction may be associated with a poorer prognosis in pediatric cancer patients. Future studies should corroborate these findings in other populations, examine the influence of other potential confounders, and determine the role of CVC dysfunction in prognostic models of cancer survival.

Intestinal Failure: A Description of the Problem and Recent Therapeutic Advances

Pediatric intestinal failure occurs when gut function is insufficient to meet the nutrient and hydration needs of the growing child. The commonest cause is short bowel syndrome with maldigestion and malabsorption following massive bowel loss. The remnant bowel adapts during the process of intestinal rehabilitation. Management promotes the achievement of enteral autonomy while mitigating the risk of comorbid disease. The future of care is likely to see expansion of pharmacologic methods for augmenting bowel adaptation, tissue engineering techniques enabling immune suppression-free autologous bowel transplant, and the development of electronic health record tools for efficient, collaborative study and care improvement.

Development of a paediatric central venous access device database: A retrospective cohort study of practice evolution and risk factors for device failure

AIM

To describe practice evolution, complications and risk factors for multiple insertion attempts and device failure in paediatric central venous access devices (CVADs).

METHODS

A paediatric retrospective cohort study using prospectively collected data from CVAD database 2012-2014. Data included were patient (i.e. age, condition), insertion (i.e. indication, device, technique) and removal (complications, dwell). Descriptive statistics and incidence rates were calculated per calendar year and compared. Risk factors for multiple insertion attempts and failure were explored with logistic regression and cox regression, respectively.

RESULTS

A total of 1308 CVADs were observed over 273 467 catheter-days in 863 patients. Multiple insertion attempts remained static (14%) and significantly associated with non-haematological oncology (odds ratio 2.19; 95% confidence interval (CI) 1.08-4.43), respiratory (3.71; 1.10-12.5), gastroenterology (4.18; 1.66-10.5) and other (difficult intravenous access) (2.74; 1.27-5.92). CVAD failure decreased from 35% (2012) to 25% (2014), incidence rate from 1.50 (95% CI 1.25-1.80) to 1.28 (1.06-1.54) per 1000 catheter-days. Peripherally inserted CVAD failure was significantly associated with lower body weight (per kilogram decrease, hazard ratio (HR) 1.02; 95% CI 1.00-1.03), cephalic vein (1.62; 1.05-2.62), difficult access (1.92; 1.02-3.73), sub-optimal tip placement (1.69; 1.06-2.69) and gastroenterology diagnosis (2.27; 1.05-4.90). Centrally placed CVAD failure was significantly associated with younger age (per year, HR 1.04; 95% CI 1.00-1.07), tunnelled device (3.38; 2.41-4.73) and gastroenterology diagnosis (1.70; 1.06-2.73).

CONCLUSIONS

While advancement in CVAD practices improved overall CVAD insertion and failure outcomes, further improvements and innovation are necessary to ensure improved vessel health and preservation for children requiring CVAD.

Care and management of children with a totally implanted central venous access device: portacath

Research and advances in technology have enabled children and young people with life-limiting conditions to live longer. To maintain their well-being and quality of life many of these children usually require some form of intravenous access for treatment. Children's nurses should have the skills and training to ensure they are competent to practise using totally implanted central venous access devices such as portacaths (ports). This article addresses the care and management of these ports in children and the wide variation in practice that exists in the UK, and makes recommendations for practice.

A novel technique for removing a fibrin sheath from a mediport catheter in the pediatric population

Mediport (also known as port, portacath or Infusaport) is a commonly placed central venous access in pediatric patients. Fibrin sheath formation around the central venous catheter is a common biological response leading to port malfunction in the form of inability to aspirate but preserved capacity for infusion of fluids. If fibrinolytic therapy fails, percutaneous fibrin sheath stripping via transfemoral route or replacement with a new mediport are routine/conventional treatments for a fibrin sheath. We describe a novel technique for removing a fibrin sheath by exteriorizing the catheter through the neck entry site, stripping the fibrin sheath from the catheter manually under sterile conditions and replacing the catheter via a peel-away sheath introduced through the same skin incision as an alternative to complete port replacement or attempted catheter stripping.

Risks of long-term port use in enzyme replacement therapy for lysosomal storage disorders

Totally implantable vascular access devices (TIVADs) are commonly used in conjunction with enzyme replacement therapy (ERT) for lysosomal storage disorders (LSDs). This case series describes potential complications associated with long-term TIVAD use, such as compromise of skin integrity, infection, or port failures. Best practices and skilled specialists are essential for minimizing complications from long-term TIVAD use for ERT.

A Pilot Randomized Controlled Trial of Novel Dressing and Securement Techniques in 101 Pediatric Patients

PURPOSE

To evaluate feasibility of an efficacy trial comparing peripherally inserted central catheter (PICC) dressing and securement techniques to prevent complications and failure.

MATERIALS AND METHODS

This pilot, 3-armed, randomized controlled trial was undertaken at Royal Children's Hospital and Lady Cilento Children's Hospital, Brisbane, Australia, between April 2014 and September 2015. Pediatric participants (N = 101; age range, 0-18 y) were assigned to standard care (bordered polyurethane [BPU] dressing, sutureless securement device), tissue adhesive (TA) (plus BPU dressing), or integrated securement dressings (ISDs). Average PICC dwell time was 8.1 days (range, 0.2-27.7 d). Primary outcome was trial feasibility including PICC failure. Secondary outcomes were PICC complications, dressing performance, and parent and staff satisfaction.

RESULTS

Protocol feasibility was established. PICC failure was 6% (2/32) with standard care, 6% (2/31) with ISD, and 3% (1/32) with TA. PICC complications were 16% across all groups. TA provided immediate postoperative hemostasis, prolonging the first dressing change until 5.5 days compared with 3.5 days and 2.5 days with standard care and ISD respectively. Bleeding was the most common reason for first dressing change: standard care (n = 18; 75%), ISD (n = 11; 69%), TA (n = 4; 27%). Parental satisfaction (median 9.7/10; P = .006) and staff feedback (9.2/10; P = .002) were most positive for ISD.

CONCLUSIONS

This research suggests safety and acceptability of different securement dressings compared with standard care; securement dressings may also reduce dressing changes after insertion. Further research is required to confirm clinically cost-effective methods to prevent PICC failure.

Innovative dressing and securement of tunneled central venous access devices in pediatrics: a pilot randomized controlled trial

BACKGROUND

Central venous access device (CVAD) associated complications are a preventable source of patient harm, frequently resulting in morbidity and delays to vital treatment. Dressing and securement products are used to prevent infectious and mechanical complications, however current complication rates suggest customary practices are inadequate. The aim of this study was to evaluate the feasibility of launching a full-scale randomized controlled efficacy trial of innovative dressing and securement products for pediatric tunneled CVAD to prevent complication and failure.

METHODS

An external, pilot, four-group randomized controlled trial of standard care (bordered polyurethane dressing and suture), in comparison to integrated securement-dressing, suture-less securement device, and tissue adhesive was undertaken across two large, tertiary referral pediatric hospitals in Australia. Forty-eight pediatric participants with newly inserted tunneled CVADs were consecutively recruited. The primary outcome of study feasibility was established by elements of eligibility, recruitment, attrition, protocol adherence, missing data, parent and healthcare staff satisfaction and acceptability, and effect size estimates for CVAD failure (cessation of function prior to completion of treatment) and complication (associated bloodstream infection, thrombosis, breakage, dislodgement or occlusion). Dressing integrity, product costs and site complications were also examined.

RESULTS

Protocol feasibility was established. CVAD failure was: 17% (2/12) integrated securement-dressing; 8% (1/13) suture-less securement device; 0% tissue adhesive (0/12); and, 0% standard care (0/11). CVAD complications were: 15% (2/13) suture-less securement device (CVAD associated bloodstream infection, and occlusion and partial dislodgement); 8% (1/12) integrated securement-dressing (partial dislodgement); 0% tissue adhesive (0/12); and, 0% standard care (0/11). One CVAD-associated bloodstream infection occurred, within the suture-less securement device group. Overall satisfaction was highest in the integrated securement-dressing (mean 8.5/10; standard deviation 1.2). Improved dressing integrity was evident in the intervention arms, with the integrated securement-dressing associated with prolonged time to first dressing change (mean days 3.5).

CONCLUSIONS

Improving the security and dressing integrity of tunneled CVADs is likely to improve outcomes for pediatric patients. Further research is necessary to identify novel, effective CVAD securement to reduce complications, and provide reliable vascular access for children.

TRIAL REGISTRATION

ACTRN12614000280606 ; prospectively registered on 17/03/2014.

Thrombotic complications and tip position of transjugular chronic dialysis catheter scheduled into superior vena cava: Findings on HR-MRCP and HR-T2WI

BACKGROUND

Catheter-related thrombotic complications(TCs) can occur during the long term use of a chronic dialysis catheter (CDC), including fibrin sheath (FS), mural thrombosis (MT), venous thrombosis (VT), and intraluminal clots (IC), which has not been reported with MRI. The aim of our study was to evaluate the determination of catheter tip position (TP) and resolution of TCs in patients with transjugular CDC scheduled into the superior vena cava using high resolution magnetic resonance cholangiopancreatography (HR-MRCP) and T2-weighted imaging (HR-T2WI).

METHODS

The study protocol was approved by the local Research Ethics Committee. Informed consent was obtained from all patients. In total, 41 consecutively enrolled transjugular CDC patients with suspected catheter dysfunction were scanned with HRMRCP and HR-T2WI. The distance from the top to the tip of the catheter and the presence and nature of catheter TCs were assessed by 2 experienced radiologists. Chest x-ray was taken within 1 to 2 days and CDC was withdrawn within 3 to 10 days from those patients with TCs identified by HR-MRI.

RESULTS

A total of 38 subjects successfully underwent HR-MRI, including 13 normal and 25 with TCs (fibrin sheath [FS]: n = 21, mural thrombosis [MT]: n = 7, venous thrombosis [VT]: n = 3, intraluminal clots [IC]: n = 4). There was no significant difference between HR-MRCP and chest x-ray in catheter TP determination (P = .124). Normal catheter appeared as "double eyes" on HR-T2WI and "double tracks" on HR-MRCP. TCs appeared as follows: FS displayed as a "thin ring" (<1mm) around the catheter, MT as patchy hyperintensity and VT as a "thick ring" (>5mm) on HR-T2WI. Unilateral IC appeared as a "single eye" on HR-T2WI and a "single track" on HR-MRCP (n = 3). Bilateral IC appeared as neither "eye" nor "track" (n = 1). Catheter withdrawal confirmed FS (n = 16), MT (n = 6), VT (n = 1), and IC (n = 4).

CONCLUSION

HR-MRCP and HR-T2WI are promising methods for visualizing TP and TCs in CDC patients, and are helpful in adjusting the treatment plan and avoiding the risk of pulmonary embolism.

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.

Examining the Role of Securement and Dressing Products to Prevent Central Venous Access Device Failure: A Narrative Review

Objective: To describe the underpinning principles involved in central venous access device (CVAD) securement and dressing products to prevent CVAD failure and complications through a synthesis of research studies.

Background: Functional, dependable CVADs are a necessary part of patient care. Dressing and securement products are used to prevent CVAD failure and complications, but there is a large variety of products available for clinicians to access, with variable effectiveness.

Methods: A narrative review of studies describing the mechanisms for CVAD securement and dressing products to prevent failure and complication was undertaken. After a systematic search, 20 clinical and laboratory studies were included in the review.

Discussion: The major mechanisms by which CVAD dressing and securement products prevent failure are providing a barrier to microbial contamination and motion reduction. CVAD securement and dressing products provide these functions using coating, adhesion, antimicrobial properties, absorbency, and moisture vapor transmission without causing irritation to skin and maintaining visibility of the insertion site. The complexity of patients requiring CVAD securement and dressing means that universal recommendations across CVAD populations and broad generalization of studies from single populations (eg, intensive care) or devices (eg, peripherally inserted central catheters) are ill advised.

Conclusions: CVAD securement and dressing products provide important, multifaceted functions to prevent CVAD failure and complication.

Radiographic appearances of uncommon paediatric implants and devices

As childhood survival of chronic illness improves, long-term implanted devices will be encountered more frequently in routine radiology. In our paediatric tertiary referral hospital, we have come across several types of implanted devices that were not confidently recognised or identified by front-line staff and were often only identified by discussion with the patient, family or clinical team. This pictorial review highlights the appearance of nonvascular devices on paediatric radiographs in order to help clinicians identify the most frequent complications and to improve awareness of these important devices.

Interventional radiology in infancy

Interventional radiology (IR) is an emerging sub-speciality within paediatric medicine. In adult care, IR is largely centred on the management of vascular disease but in paediatric practice, IR applications are varied and increasingly innovative, making this an exciting field to be a part of. IR has a central role both in the day to day care of sick children, from long term IV access provision to feeding tube insertions, and in the acute management of critically ill infants, such as those with overwhelming liver disease, neonatal tumours and vascular malformations. Paediatric IR faces a unique set of challenges, developing or modifying techniques and equipment for use in very small patients, training professionals to take the speciality forward and, most importantly, convincing paediatricians and healthcare institutions to create opportunities for IR to make a difference.

Imaging and management of complications of central venous catheters

Central venous catheters (CVCs) provide valuable vascular access. Complications associated with the insertion and maintenance of CVCs includes pneumothorax, arterial puncture, arrhythmias, line fracture, malposition, migration, infection, thrombosis, and fibrin sheath formation. Image-guided CVC placement is now standard practice and reduces the risk of complications compared to the blind landmark insertion technique. This review demonstrates the imaging of a range of complications associated with CVCs and discusses their management with catheter salvage techniques.

Central venous access port devices - a pictorial review of common complications from the interventional radiology perspective

Portacaths are tunnelled and totally implanted central venous access port devices (CVAPD). They are commonly used for intravenous antibiotic delivery in patients with cystic fibrosis. More recently, they are being used in oncology to deliver chemotherapy and apheresis. It is therefore important to be aware of portacath associated complications and their imaging features. This pictorial review illustrates and discusses common complications associated with Portacath devices.

Interventions for restoring patency of occluded central venous catheter lumens

BACKGROUND

Central venous catheters (CVCs) facilitate the administration of intravenous drugs, fluids, blood products and parenteral nutrition to patients with either chronic disease or critical illness. Despite a pivotal role within medical management, a common complication associated with CVC use is occlusion of the CVC lumen(s). CVC occlusion can interrupt and cause serious delays in administration of treatment interventions.

OBJECTIVES

The primary objective of this review was to assess the efficacy and safety of different interventions used to restore patency of occluded CVC lumens, in adults and children.

SEARCH METHODS

We identified trials by searching the Cochrane Central Register of Clinical Trials (CENTRAL) (The Cochrane Library 2011, Issue 9); OvidSP MEDLINE (1950 to September 2011); OvidSP EMBASE (1980 to September 2011) and NHS Evidence CINAHL (1982 to September 2011). We also searched clinical trial registers, handsearched reference lists, contacted pharmaceutical companies and authors of publications that met the inclusion criteria to identify trials.

SELECTION CRITERIA

We selected randomized controlled trials which investigated the efficacy of an intervention (chemical, surgical or drug) used to restore patency to an occluded CVC lumen, in either adults or children.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed those studies that met the inclusion criteria for quality and extracted the relevant data using a standardized form.

MAIN RESULTS

No studies were found that investigated the efficacy and safety of either chemical or surgical interventions.Seven studies (eight papers) with a total of 632 participants were identified from the search. They investigated different comparisons, strengths of thrombolytic or anticoagulant drug interventions for treating CVC lumen occlusion thought to be caused by a thrombus.There was low quality evidence from a meta-analysis of two studies suggesting that urokinase (various strengths) was more effective than placebo for restoring patency to occluded CVC lumens in adults and children with underlying medical conditions (relative risk (RR) 2.09, 95% confidence interval (CI) 1.47 to 2.95), with a number needed to treat of 4 (95% CI 2 to 8). There was insufficient evidence to draw conclusions on the safety of urokinase.The overall quality of the evidence provided by these studies was low to very low due to one or more domains being assessed as either at 'unclear risk of bias' or 'high risk of bias'. Furthermore, the total number of participants in these studies was small and consequently may lead to spurious results.

AUTHORS' CONCLUSIONS

There is inadequate evidence to draw strong conclusions on the efficacy or safety of the drug interventions included in this review. There is some low quality evidence from a meta-analysis of two studies investigating urokinase (various strengths) and some very low evidence from two single studies investigating alteplase 2 mg/2 mL that suggest that these two drug interventions may be effective in treating withdrawal or total occlusion of CVC lumens caused by thrombosis. Further high quality, sufficiently powered research is still required to look at the efficacy and safety of urokinase, alteplase and other chemical, surgical and drug interventions for treating CVC lumen occlusion. Research studies which exclusively include child participants are especially warranted.

Venous thromboembolism in cystic fibrosis

The incidence of venous thromboembolism (VTE) is increasing in the pediatric population. Individuals with cystic fibrosis (CF) have an increased risk of thrombosis due to central venous catheters (CVCs), as well as acquired thrombophilia secondary to inflammation, or deficiencies of anticoagulant proteins due to vitamin K deficiency and/or liver dysfunction. CVC-associated thrombosis commonly results in line occlusion, but may develop into serious life-threatening conditions such as deep venous thrombosis (DVT), superior vena cava syndrome or pulmonary embolism (PE). Post-thrombotic syndrome (PTS) may be a long complication. Local occlusion of the catheter tip may be managed with instillation of thrombolytics (such as tPA) within the lumen of the catheter; however, CVC-associated thrombosis involving the proximal veins is most often is treated with systemic anticoagulation. Initial treatment with heparin is a standard approach, but thrombolytic therapy, which may carry higher bleeding risks, should be considered for life and limb threatening episodes of VTE. Recommended duration of anticoagulation with low molecular weight heparin (LMWH) or warfarin ranges from 3 to 6 months for major removable thrombotic risks; longer anticoagulation is considered for recurrent thrombosis, major persistent thrombophilia, or the continued presence of a major risk factor such as a CVC. While CVCs are the most common risk for development of VTE in children, studies have not demonstrated a clear benefit with routine use of systemic thromboprophylaxis. The incidence and risk factors of VTE in CF patients will be reviewed and principles of diagnosis and management will be summarized.

Management of non-infectious central venous access device complications

OBJECTIVES

To review the central venous access device (VAD) complications of inadvertent device damage, device malfunction, and various causes of mechanical occlusion and to describe the limitations of VAD complication data.

DATA SOURCES

Journal articles, legal cases, case reports, manufacturers' product information, personal experience.

CONCLUSION

The available data on VAD complications are difficult to interpret and apply in practice because of the many limitations of the studies that have been conducted (eg, single-institution, mixed patient populations, inconsistent measurement of complications). However, considerable information is known about the signs and symptoms of non-thrombotic, non-infectious VAD complications and their management.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses routinely use central VADs and are on the frontline for detecting VAD complications. Well-informed nurses can serve as patient advocates and help ensure that patients' VADs are functional and safe to use.

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.