Use of central venous catheters in children with severe congenital coagulopathy

Utility of Blood Cultures and Empiric Antibiotics in Febrile Pediatric Hemophilia Patients With Central Venous Access Devices

BACKGROUND

Children with hemophilia frequently require long-term central venous access devices (CVADs) for regular infusion of factor products. Hemophilia patients are not immunocompromised, but the presence and use of CVADs are associated with infections including bacteremia. Currently, the utility of blood cultures in evaluation of the febrile hemophilia patient with an indwelling CVAD is unknown, nor is optimal empiric antibiotic use.

METHODS

We performed a retrospective cross-sectional study of febrile immunocompetent hemophilia patients with CVADs presenting to a large academic urban pediatric emergency department from 1995 to 2017. We used a natural language processing electronic search, followed by manual chart review to construct the cohort. We analyzed rate of pathogen recovery from cultures of blood in subgroups of hemophilia patients, the pathogen profile, and the reported pathogen susceptibilities to ceftriaxone.

RESULTS

Natural language processing electronic search identified 181 visits for fever among hemophilia patients with indwelling CVADs of which 147 cases from 44 unique patients met study criteria. Cultures of blood were positive in 56 (38%) of 147 patients (95% confidence interval, 30%-47%). Seventeen different organisms were isolated (10 pathogens and 7 possible pathogens) with Staphylococcus aureus and coagulase-negative Staphylococcus species as the most common. Thirty-four percent of isolates were reported as susceptible to ceftriaxone. Positive blood cultures were more common in cases involving patients with inhibitors (n = 71) versus those without (n = 76), odds ratio, 7.4 (95% confidence interval, 3.5-15.9). This was observed irrespective of hemophilia type.

CONCLUSIONS

Febrile immunocompetent hemophilia patients with indwelling CVADs have high rates of bacteremia. Empiric antimicrobial therapy should be targeted to anticipated pathogens and take into consideration local susceptibility patterns for Staphylococcus aureus.

Prophylactic versus on-demand treatments for hemophilia: advantages and drawbacks

INTRODUCTION

Early long-term prophylaxis is the standard of care to prevent joint bleeding and chronic arthropathy in patients with severe hemophilia. Areas covered: Despite the obvious prophylaxis advantages upon the clinical outcomes, there are still several drawbacks to be addressed for the optimal patients' compliance. Frequency of treatment due to short half-life of conventional FVIII and FIX concentrates, difficult venous access, adherence to the prescribed therapy and costs may represent significant critical issues. The development of inhibitors also makes replacement therapy ineffective, preventing patients from receiving long-term prophylaxis. This paper will review these drawbacks and the tools to overcome these limitations, mainly thanks to the use of extended half-life products and the development of novel non-conventional therapeutic approaches. Expert commentary: The use of extended half-life products may help in reducing the burden of the frequent intravenous administration and in better tailoring an individualized prophylaxis. The development of novel therapeutic approaches, like the bi-specific antibody mimicking the coagulation function of FVIII or inhibition of anticoagulant proteins may facilitate prophylaxis treatment not only in patients with inhibitors, but also in severe hemophilia patients without inhibitors. Exciting opportunities are emerging for improving prophylaxis in hemophilia.

Central venous access devices in patients with hemophilia

Hemophilia is a hereditary disorder in which the major clinical manifestation is bleeding into the joints, muscles, internal organs and the CNS, often without any obvious trauma. Bleeding can be fatal as in the case of CNS hemorrhage, or severely debilitating following repeated bleeding into joints that results in crippling arthritis. Treatment for hemophilia includes the intravenous administration of clotting factor concentrates to replace the missing or defective protein. Venous access is therefore critical to the treatment of hemophilia and the prevention of complications due to bleeding. According to the US Centers for Disease Control and Prevention, approximately half of patients less than 16 years of age and one-third of all patients with hemophilia receive regular prophylactic injections of clotting factor concentrates. Prophylaxis, or the regular scheduled administration of antihemophilic factor concentrate, is effective in preventing bleeding. Among those patients with severe disease, in the absence of prophylaxis, approximately 13 bleeds, including nine joint hemorrhages, occur annually. In contrast, when prophylaxis is administered, the annual number of total and joint bleeds decreases to five and three, respectively. One of the major barriers to the more wide-spread use of prophylaxis is venous access. While peripheral venipuncture remains the first choice for venous access, central venous access devices are frequently used to facilitate repeated and/or urgent administration of clotting factor concentrates. The advantages of central venous access devices are well recognized in certain treatment regimens such as prophylaxis and immune tolerance therapy, as well as certain patient groups such as young children in whom venipuncture is often difficult and traumatic, and adults with scarred veins. Central venous access devices also allow earlier commencement of both home treatment and prophylaxis. The goal of this review is to discuss the different types of central venous access devices and their role in the management of hemophilia to provide practitioners that care for patients with hemophilia with the necessary information to make sound therapeutic recommendations to their patients.

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.

Venous access in haemophilic children: choice and management

Current haemophilia treatment in children is based on regular intravenous infusions of concentrates for prolonged periods, according to prophylaxis regimens or immune tolerance induction treatment, in cases of inhibitor development. Therefore, a stable and uncomplicated venous access is required and as such peripheral veins represent the preferred option. However, frequent infusions in the home setting can be problematic in very young children and for this reason, central venous access devices (CVADs) have been widely used to improve treatment feasibility. Unfortunately CVADs' use is associated with a high rate of complications, and infections and thrombotic occlusion can influence treatment outcome by causing unwanted treatment interruption. CVADs can be grouped into three main categories: external non-tunnelled, external tunnelled and fully implantable devices known as ports. The management of CVADs at home often represents a challenge because a strict adherence to sterile procedures is required. Indeed, the incidence of infections with ports is much lower than that reported for external devices; however, ports carry the inconvenience of needle sticks. More recently, arteriovenous fistula was shown to be a suitable alternative to CVADs because it is easy to use and is associated with a lower rate of complication.

Central venous access devices for paediatric patients with haemophilia: a single-institution experience

Use of a central venous access device (CVAD) can facilitate early introduction of home-based infusion of factor concentrate for long-term prophylaxis or immune tolerance therapy in children with bleeding disorders. The aim was to review outcomes associated with use of CVAD. Retrospective review of paediatric patients with bleeding disorders was observed at the Mayo Clinic Comprehensive Hemophilia Center. Thirty-seven CVAD were placed in 18 patients (haemophilia A [n = 15], type 3 von Willebrand disease [n = 2] and haemophilia B [n = 1]). Follow-up was for 45 952 CVAD days, and median time that CVAD remained in place was 1361 days per device. Factor VIII (FVIII) inhibitors were present in 4 of the 15 patients. Ten CVAD-related infections occurred (median, 672 days; range, 72-1941 days), of which six were in one patient with FVIII inhibitors. Overall infection rate was 0.22 (95% confidence interval [CI], 0.10-0.40) per 1000 CVAD days, with 0.11 infections in patients without FVIII inhibitors compared with a pooled incidence of 0.66 (95% CI, 0.44-0.97) reported in the literature. Indications for removal of 27 CVAD were blockage, change to peripheral venous access, catheter displacement, infection, leak in the port septum, short catheter and skin erosion. No clinically apparent thrombosis or sequelae of thrombosis were observed. Infection is the most common complication associated with CVAD use and is increased in patients who have inhibitors. The low rate of clinically apparent thrombosis reflects our practice of not screening for thrombosis. The low infection rate reflects our practice of using and reinforcing the aseptic technique.

Barriers to primary prophylaxis in haemophilic children: the issue of the venous access

Modem treatment for hemophilic children is based on prophylaxis and immune tolerance induction (ITI). Both treatment regimens are based on frequent infusions at early ages, therefore an adequate venous access is essential. Peripheral veins represent the best option, however, different solutions, as central venous access devices (CVADs) and arteriovenous fistulae (AVFs), can be adopted if needed. CVADs have been used in hemophiliacs, however their survival is affected by infectious complications. Among CVADs, fully implantable devices are usually preferred to external lines due to a lower infectious risk. The limited survival of CVADs may have a relevant impact on treatment outcome, especially in case of ITI where treatment interruptions are counterproductive. To overcome such drawbacks, internal AVF has been considered as an alternative option owing to a lower rate of infectious complications. Moreover, AVF is easy to use in the home setting and well accepted by children. Possible complications not preventing AVF use are postoperative hematoma and transient symptoms of distal ischemia; one case of symptomatic thrombosis has been reported so far. Long-term complications include loss of patency, aneurysmatic dilatation and, rarely, limb dysmetria and a regular follow-up is mandatory to allow early remedial intervention. Surgical dismantlement of AVF is recommended as soon as transition to peripheral veins is possible.

Therapeutic use of arteriovenous fistula in children with haemophilia

Haemophilia is an X-linked inherited bleeding disorder, which only affects males. Contemporary treatment of children with haemophilia requires adequate venous access for the administration of prophylactic therapy which commences as a relatively early age. In the majority of children this treatment is administered at home, usually by the parents and then, once competent, by the boys themselves. As venous access in young children is fraught with difficulty, central venous access devices have become the mainstay of haemophilia care. However, these devices come with their own difficulties, with infection and thrombosis causing significant side-effects in some children. Small but substantial cohorts of boys with haemophilia develop antibodies (or inhibitors) to coagulation factors, rendering them both more likely to experience bleeding and more complex to treat. These boys are, for reasons not yet fully understood, more likely to experience central line infections, which also affect overall treatment outcomes. Arteriovenous fistulae were used in four such boys in an attempt to eliminate central line infection and to enable continued treatment administration. The experience and outcomes of these four boys is discussed along with considerations and implications for nurses caring for them.

Cost-utility analysis of Canadian tailored prophylaxis, primary prophylaxis and on-demand therapy in young children with severe haemophilia A

Primary prophylaxis is the emerging standard treatment for boys with severe haemophilia. Tailored (escalating-dose) prophylaxis (EscDose), beginning at a low frequency and escalating with repeated bleeding may prevent arthropathy at a lower cost than standard prophylaxis (SP). From a societal perspective, we compared the incremental cost per joint-haemorrhage that is avoided and quality-adjusted-life-year (QALY) gained of SP and EscDose to on-demand (Demand) therapy in severe haemophilia A boys treated to age 6 using a decision analytic model. Costs included factor VIII (FVIII), professional visits and tests, central venous placement/complications, hospitalization, home programmes and parents' lost work-days. Resource utilization was estimated by surveying 17 Canadian clinics. The natural history of bleeding and other probabilities were determined from a longitudinal chart review (n = 24) and published literature. EscDose costs an additional $3192 per joint-haemorrhage that was avoided compared with Demand whereas SP costs an additional $9046 per joint-haemorrhage that was avoided compared with EscDose. Clinic costs and lost wages were reduced by 60-80% for EscDose and SP compared with Demand. EscDose attained more QALYs than SP and Demand on account of less bleeding than Demand and lower need for ports than SP. The incremental cost per QALY for EscDose vs. Demand was $542 938. EscDose was less expensive with similar QALYs compared to SP. Sensitivity analysis was performed on all probability- and cost-estimates, and showed the model was sensitive to the cost of FVIII and the SP and target joint utilities. In conclusion, prophylaxis will substantially improve clinical outcomes and quality of life compared to Demand treatment, but with substantial cost.

Recombinant tissue plasminogen activator may reduce frequency of central venous access device infection in hemophilia patients undergoing immune tolerance therapy

Many patients with hemophilia, particularly those with inhibitory antibodies, utilize central venous access devices (CVADs) to facilitate frequent infusions. Infection of these devices is a common complication of factor replacement therapy. This communication reports our center's experience with CVAD infection in three patients with severe hemophilia A undergoing immune tolerance therapy (ITT) in whom intermittent infusions of recombinant tissue plasminogen activator (rTPA, Cathflo Activase) were utilized. In this small experience, patients experienced a decreased frequency of gram-positive infections when receiving routine rTPA treatments. Larger randomized trial should be performed in this patient population at high risk of CVAD infection.

The risk associated with indwelling catheters in children with haemophilia

Infections are the most frequent complications associated with the use of central venous lines (CVLs) in children with haemophilia. Several retrospective studies that include data from a substantial number of patients have reported approximately 0.2-0.3 infections per 1000 catheter-days (mainly Port-A-Cath). Some studies have shown a much higher frequency of infections, 1-2/1000 catheter-days. The most plausible explanations, for the difference seen in frequency of infections with Port-A-Caths, are probably related to the protocol used for the device care and the quality of education and the compliance of the users, whether these are parents or health-care professionals. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not performed in most of these series. In studies, where this has been performed, a high frequency of abnormalities (>50%) on venograms have been seen in some series but not in others. Despite obvious potential risks with CVLs, they are useful in many cases and facilitate the treatment of a serious disorder. With careful guidelines and surveillance protocols, the risk of complications should be reduced in the future.

Inadvertent anticoagulation of a haemophiliac child with routine line flushing

We report the case of a 3-year-old boy with severe haemophilia A presenting with recurrent haemarthroses despite daily infusions of factor VIII delivered through a central venous access device (CVAD). Regular rinsing of the CVAD with heparin, according to a standard protocol, resulted in systemic anticoagulation, as demonstrated by prolonged thrombin time and therapeutic anti-Xa levels. The bleeding symptoms resolved after replacing heparin with a normal saline solution. This case illustrates that heparin administered to maintain CVAD patency should be used with caution in young haemophiliacs. Prolonged thrombin time should alert the physician to this possible CVAD complication.

Current issues in prophylactic therapy for persons with hemophilia

Factor VIII or IX replacement in a prophylactic manner is utilized for many patients with moderate to severe hemophilia A or B. Studies have shown it to be effective in reducing or preventing degenerative joint disease in many but not all patients. However, many unanswered questions still exist and optimization of this expensive treatment regimen is needed. This paper recounts the current products that are available for use and explores the literature regarding different treatment regimens. It explores age at initiation, dose, interval between infusions, joint health outcomes, barriers to compliance and age at discontinuation of prophylaxis. Individualized treatment is recommended. Collaborative efforts are needed to improve outcomes for all persons with hemophilia.

Fatal central venous catheter-related infection in haemophilia

Central venous catheters (CVC) are frequently used in children with haemophilia to deliver factor infusions for the treatment or prophylaxis of bleeding. Complications of CVCs in patients with haemophilia include thrombosis and infection. We report a young boy with severe haemophilia A and an inhibitor who developed disseminated Staphylococcus aureus infection most likely related to a CVC. To our knowledge, this is the first reported case of fatal sepsis secondary to a CVC in a patient with haemophilia.

Consensus recommendations for use of central venous access devices in haemophilia

Venous access is essential for delivery of haemophilia factor concentrate. Wherever possible, peripheral veins remain the route of choice, and the use of central venous access devices (CVADs) should be limited to cases of clear need in patients with caregivers able to exercise diligence in CVAD care and should continue no longer than necessary. CVADs are of recognized value for repeated administration of coagulation factors in haemophilia, particularly for prophylaxis and immune tolerance therapy and in young children. Evidence to guide best practices has been fragmentary, and standardized methods for CVAD usage have yet to be established. We have developed management recommendations based upon available published evidence as well as extensive clinical experience. These recommendations address patient and CVAD selection; CVAD placement, care and removal; caregiver/patient guidance; and complications, including infection and thrombosis. In the absence of inhibitors, ports are recommended, primarily because of fewer associated infections than with external catheters. For patients with inhibitors, ports also appear to be associated with fewer infections. Infection is the most frequent complication, and recommendations to prevent and treat infections are supported by extensive clinical data and experience. Strict adherence to handwashing and aseptic technique are essential elements of catheter care. Evidence-based data regarding the detection and treatment of CVAD-related thrombotic complications are limited. Caregiver education is an integral part of CVAD use and the procedural practices of users should be regularly re-assessed. These recommendations provide a basis for sound current CVAD practice and are expected to undergo further refinements as new evidence is compiled and clinical experience is gained.

Successful induction of immune tolerance with FIX recombinant in a patient with haemophilia B with inhibitor

We describe successful induction of immune tolerance in a 12-month-old patient with severe haemophilia B and low-titre and low response antifactor IX inhibitor at 5 Bethesda Unit (BU). Immune tolerance induction (ITI) was started with recombinant factor (rFIX) at 40-50 U kg(-1) day(-1) (1000 U three times per week) and 2 years after the beginning of therapy the inhibitor had been reduced to undetectable values. As complications, which appeared during the ITI, the patient presented minor haemorrhagic complications, which remitted following the administration of rFVIIa, and recurring infections of the catheter, requiring the withdrawal and subsequent placement of a new catheter.

Central venous catheters in children with haemophilia

Infections, thrombosis and technical problems are the most frequent complications when using implantable central venous access devices in patients with haemophilia. There seem to be two major experiences concerning infections in non-inhibitor patients, one is approx. 0.2 infections per 1000 days and the other approx. 1.0(0.7-1.6)/1000 days. Infections are more frequent in inhibitor patients and one can expect approx. one infection per 6-12 months of use. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not done in most of these series. In studies where this has been done, a high frequency of abnormalities on venograms have been seen in some but not in others. The final decision to use a central line has to be a compromise between the medical goal, the patient's bleeding tendency, the social situation and the expected risk of complications at the particular haemophilia center. Some of the complications may be reduced by adequate aseptic measures both during implantation and in the subsequent use and clear basic routines for surveillance of the systems and repeated education of the users.

Home management of haemophilia

The demonstrated benefits of home care for haemophilia include improved quality of life, less pain and disability, fewer hospitalizations, and less time lost from work or school. Although reduced mortality has not been demonstrated, the substantial increase in longevity since the early 1980s correlates with the introduction of home treatment and prophylaxis programmes. These programmes must be designed and monitored by haemophilia treatment centres (HTC), which are staffed with professionals with broad and complementary expertise in the disease and its complications. In return, patients and their families must be willing to accept the reciprocal responsibilities that come from administering blood products or their recombinant equivalents at home. Patients with inhibitors to factors VIII or IX pose special challenges, but these complications do not obviate participation in home care programmes. Home care was an essential prerequisite to the introduction of effective prophylactic factor replacement therapy. Prophylaxis offers significant improvements in quality of life, but requires a substantial commitment. The use of implantable venous access devices can eliminate some of the difficulty and discomfort of peripheral venous access in small children, but brings additional risks. The future holds the promise of factor concentrates for home use that have longer half-lives, or can be administered by alternate routes. Knowledge of patient genotypes may allow treatments tailored to avoid complications such as inhibitor development. Gene therapy trials, which are currently ongoing, will ultimately lead to gene-based treatments as a complement to traditional protein-based therapy.

Central venous access devices in haemophilia

Central venous access devices (CVADs) can facilitate repeated and/or urgent administration of coagulation factors in haemophilic patients. We conducted a systematic review and meta-analysis of complication rates and risk factors for poor outcome. Forty-eight studies with a total of 2704 patients and 2973 CVADs were included. The primary indications for CVADs were immune tolerance therapy (34.9% of patients), difficult venous access (31.8%) and prophylaxis (29.1%). Fully implanted CVADs were employed in 77.4% of cases and external CVADs in 22.6%. A total of 1190 infections were reported, and the pooled incidence of infection was 0.66 per 1000 CVAD days [confidence interval (CI), 0.44-0.97 per 1000 CVAD days]. Among patients developing infection, the pooled time to first infection was 295 days (CI, 181-479 days). Presence of inhibitors was an independent risk factor for infection with an incidence rate ratio (IRR) of 1.67 (CI, 1.15-2.43). Infection was less likely in patients >6 years of age (IRR, 0.46; CI, 0.27-0.79) and recipients of fully implanted CVADs (IRR, 0.31; CI, 0.12-0.86). Available information on thrombosis was limited, with only 55 cases being reported. Eventually, 31.3% of CVADs were removed, and infection was the reason for removal in 69.9% of cases and thrombosis in 4.1%. The pooled time period CVADs remained indwelling prior to removal or the expiration of the study observation period was 578 days per CVAD (CI, 456-733 days per CVAD). CVADs can confer major benefits in patients with haemophilia requiring long-term venous access, and serious complications are rare.

Long-term safety and feasibility of arteriovenous fistulae as vascular accesses in children with haemophilia: a prospective study

Infectious and thrombotic complications limit the long-term use of subcutaneous ports as venous accesses for children with haemophilia. This study has evaluated for the first time the safety and feasibility of internal arteriovenous fistulae (AVF) as alternative accesses. During the 3-year study period, 27 severe haemophiliacs, 14 with factor VIII inhibitors (52%), underwent the creation of 31 proximal AVF in the forearm. Mild forearm haematomas were observed after five procedures (16%) in five patients who had or developed inhibitors after surgery. Inadequate AVF maturation was observed after five of 31 procedures (16%) in four children. AVF were first accessed after a median of 42 d and regularly used at home by 26 patients (96%) for a median follow-up period of 29 months. Thrombosis of a venous branch occurred in one AVF (3%) after 9 months of uncomplicated use in a child with inhibitor who spontaneously recovered from the symptoms and still used AVF for nine additional months. Mild symptoms, referable to distal ischaemia, were transiently reported by two children (7%) who needed no remedial intervention. This study demonstrates that the use of AVF in haemophiliacs enabled long-term treatment at home in all patients but one.

Surveillance of infectious complications associated with central venous access devices in children with haemophilia

PURPOSE

To analyse the risk factors for infection associated with central venous access device (CVAD) use in children with haemophilia.

METHODS

Risk factors for CVAD infection among patients with congenital haemophilia who had had a CVAD implanted at a single institution were evaluated utilizing the following variables: age at CVAD placement, age at end of study, number of days with a CVAD, percentage of lifetime with a CVAD, and history of inhibitor.

RESULTS

Fifty-nine patients had a total of 97,936 (median 1768 days per patient) CVAD days in the study period. The median age at CVAD placement was 2.7 years (range 0-14.0). Twenty-six (44%) patients reported CVAD infections during the study period from January 1993 to October 2000. Twenty-four patients had their CVAD replaced, 17 (71%) of whom reported having infections and seven (29%) of whom had a history of inhibitor. The strongest predictor for having any infections was inhibitor status (P=0.16), although none of the risk factors had statistically significant effects. Among the 26 patients reporting infections, 42% had more than one CVAD-related infection. Seven patients had multiple infections involving the same organism. The mean rate of infection was 0.45 per 1000 catheter days, with a 95% confidence interval of 0.33-0.60. Those with a history of inhibitor had an infection rate of 0.66 compared with 0.38 per 1000 catheter days (P=0.09) for those without a history of inhibitor. Patients who were older (greater than the median age of 2.7) at CVAD placement had a lower rate of infection (0.29 vs. 0.65, P<0.01) compared with those < or =2.7 years. Adjustment for inhibitor status had little impact on these results. For the group as a whole, the median time to first infection was 1977 days from CVAD placement. Patients who were older at CVAD placement or study exit had lower relative hazards of infection (P=0.05 and P=0.09 respectively), while those who had inhibitors had a higher but not statistically significant relative hazard of 1.88 (P=0.13).

CONCLUSIONS

These data reveal that while considerable numbers of patients develop CVAD-related infection, the interval between catheter placement and infection can be quite long. In addition, the earlier in life a CVAD is placed, the higher the risk of infectious complications, as evidenced by the tendency towards a higher infection rate. Measures to prevent CVAD-related infection might be focused on very young patients who appear to be at higher risk.

Adverse events in the prophylaxis of haemophilia

Whilst prophylaxis undoubtedly offers many advantages, the potential for adverse effects must also be borne in mind. Modern plasma-derived products have an extremely good safety record with regard to transmission of pathogens, although continuous vigilance is required as new pathogens continue to emerge, eg new variant Creutzfeldt-Jakob disease. There is no evidence that prophylactic treatment is associated with an increased incidence of inhibitors, and it is now recognized that genetic factors are the most significant in conferring susceptibility. Although subtle immunological abnormalities have also been observed in patients with haemophilia, there is no evidence that these are of any clinical significance. There has been a growing trend to use indwelling venous catheters for prophylaxis. The risk of infection has been appreciated for some time, although it has only recently been possible to quantify this with more precision. The risk of catheter-associated thrombosis is now recognized to be higher than hitherto appreciated. Whilst sporting activities are to be encouraged, there is a potential for significant trauma in children with prophylaxis, as plasma coagulation factor levels remain far below normal with the usual regimens.

The overall effectiveness of prophylaxis in severe haemophilia

The aim of this retrospective review was to assess the overall effectiveness of prophylaxis when compared with on-demand treatment of haemophilic patients. Twenty-five children (22 with severe haemophilia A and three with severe haemophilia B) were evaluated. Five haemophilia A patients received primary prophylaxis (instituted before the onset of any joint bleed) while the other 17 haemophilia A and all three haemophilia B patients were on secondary prophylaxis. We compared factor usage, number of bleeding episodes, emergency room (ER) visits and hospitalizations while on prophylaxis to those while on demand therapy. All subjects were male, the median age at time of review was 11.4 years and at start of prophylaxis was 4.5 years. Thirteen of the 25 patients (52%) required indwelling venous catheters for access, seven of these had one or more (one-six) episodes of line sepsis. Haemophilia A patients received an average of 23.8 U kg(-1) (20-30 U kg(-1)) of recombinant factor VIII three times a week while haemophilia B patients received 50 U kg(-1) recombinant FIX twice weekly. There was a significant reduction in the mean number of major bleeds on prophylaxis from 15.5 to 1.9 per year and a significant decrease in target joints, ER visits and hospitalizations. Although factor usage per year was higher on prophylaxis, there was an overall reduction in number of bleeds and resultant decrease in hospitalizations and ER visits. By preventing new target joints, prophylaxis can lead to reduction in long-term morbidity and a better quality of life despite increased central lines and higher factor usage.

Central venous lines in haemophilia

Infections and technical problems are the most frequent complications when using implantable central venous access devices in patients with haemophilia. There are two major experiences reported concerning infections in noninhibitor patients: one is approximately 0.2 infections per 1000 days and the other approximately 1.0 (0.7-1.6) per 1000 days. Infections are more frequent in inhibitor patients and approximately one infection per 6-12 months of use can be expected. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not carried out in most of these series. In studies where this has been done, a high frequency of abnormalities on venograms has been seen in some but not in others. The final decision to use a central line has to take into account the medical goal, the patient's bleeding tendency, the social situation and the expected risk of complications at the particular haemophilia centre. Some of the complications may be reduced by adequate aseptic measures both during implantation and in subsequent use, and by clear basic routines for surveillance of the systems and repeated education of the users.

How to start prophylaxis

A cohort study was performed to assess the efficacy of a gradual introduction to primary prophylaxis by peripheral vein injections. Bleeding symptoms prior to the initiation of prophylaxis and during the time from the start of home treatment were investigated. Forty-seven boys with severe haemophilia, born between 1987 and 2000, were studied. The mean age at the start of prophylaxis was 16 months and the mean age for the boys on home treatment and full prophylaxis was 30 months. Our results show that primary prophylaxis with injections in a peripheral vein is possible in most patients (83%). Even with this early start, 59% of the children had been treated with clotting factor concentrate before prophylaxis was initiated. Seventy-two percent of the boys had no symptoms from the joints or muscles in the time from initiation to full prophylaxis every second (haemophilia A) or third day (haemophilia B). None of the patients developed cerebral bleeding during this period, but one patient had an epidural bleeding as the presenting symptom of haemophilia.

Treatment strategies in children with hemophilia

Hemophilia is an inherited bleeding disorder caused by quantitative or qualitative defects in the synthesis of factor VIII (FVIII) or factor IX (FIX). Clinically, it is divided into severe, moderate and mild disease depending on the levels of FVIII or FIX in the blood. The bleeding tendency is most pronounced and can start at a very young age in severe hemophilia, which is characterized by repeated hemorrhage into the joints and muscles. Without treatment, these episodes lead to severe arthropathy, and there is also a high risk of lethal cerebral hemorrhage. The treatment of bleeding symptoms requires the correction of the coagulation defect. Factor concentrates have been available for 30 years, initially with the development of cryoprecipitate, subsequently with increasingly purified plasma-derived forms, and ultimately with recombinant clotting factor concentrates. The advantage of this highly effective therapy has been subdued by the outbreak of HIV and Hepatitis C infections in patients with hemophilia treated with factor concentrates which did not have adequate viral inactivation steps in the purification process. Plasma-derived and recombinant factor concentrates are today considered to have a good safety profile, but are only available for a small group of hemophilia patients worldwide. A multidisciplinary team approach is important for early diagnosis, communication with the patient and parents, and to tailor the best treatment possible with the amount of clotting factor concentrates available. The main goal of hemophilia treatment is to prevent bleeding symptoms and allow normal integration in social life. In patients with severe hemophilia, this can best be achieved by early home treatment and primary prophylaxis. Future developments in gene therapy may transform severe hemophilia to a mild form, with no need for regular injections of clotting factor concentrates.

Complications of central venous access devices in paediatric haemophilia patients

We conducted a retrospective survey of our experience with central venous access devices (CVADs) implanted in children with haemophilia seen at the Vanderbilt Hemostasis-Thrombosis Clinic from 1986 to 2000. Following discussion with parents on the merits and risks associated with the use of CVADs for immune tolerance induction or factor prophylaxis, catheters were inserted under sterile technique in the operating room. One nurse provided demonstration and teaching about catheter care and access. Thirty central venous catheters were inserted in 22 children. Our survey revealed that the two most common complications associated with central venous catheters were bacteraemia and thrombosis. We found a sepsis rate of 0.30/1000 catheter-days or one episode of bacteraemia for every 3346 days of catheter use. The thrombosis rate of our cohort was 0.13/1000 catheter-days or one episode of thrombosis for every 7529 days of catheter use. Uncomplicated venous access is essential in children with severe haemophilia who require prophylaxis or immune tolerance induction. While infection was the most common complication observed in our series, we experienced a lower overall infection rate than several reported series. Catheter thrombosis and subsequent obstruction may occur as a result of intraluminal fibrin deposits. We conclude that the use of implantable central venous catheters is an effective method for accessing children with haemophilia. We accept that the benefits of CVADs in the treatment of paediatric haemophilia patients outweigh the previously documented risks. Future prospective studies should be designed to define all associated risks and to determine effective strategies to reduce them.

State of care for hemophilia in pediatric patients

On demand treatment of bleeding episodes is still the main approach to hemophilia care of patients of any age. Prompt infusion of coagulation factor concentrate in the home setting allows treatment of hemorrhages at early onset, reducing the incidence of complications and improving the quality of life. Nevertheless, the technological evolution and progressive improvement in the safety of therapeutic products have changed the management of the disease, particularly in children. The current availability of safer concentrates has drastically reduced the risk of transmission of blood-borne infections. Innovative approaches, such as early primary prophylaxis and immune tolerance induction, have become feasible and their introduction represents a major advance in the achievement of the main therapeutic goals: control of the bleeding diathesis and elimination of inhibitors. Prophylactic regimens have been shown to be effective in preventing the occurrence not only of joint bleeding but also of arthropathy when started early in children with severe hemophilia. Inhibitor development still represents the main complication of hemophilia treatment, making concentrate administration ineffective. Immune tolerance induction by daily infusion of coagulation factor concentrate was shown to eradicate the inhibitors in 63 to 83% of patients. These intensive treatment regimens are administered at home to very young children and create the problem of adequate venous access. Subcutaneous venous ports have been used in patients with hemophilia if peripheral veins could not be frequently accessed; however, the risk of infection is an important limit to their use.

Paediatric care of the child with haemophilia

The paediatric care of children with haemophilia in developed countries should focus on the health of the child, not on the disorder. Gene therapy offers the hope of an ultimate 'cure' for the disorder, but until this is a viable proposition, patients should be given more control over their treatment, and the focus should be on 'self-monitored and self-adjusted' prophylaxis. New instruments for measuring joint function and radiographic changes, and quality of life are valuable tools in improving the treatment of paediatric care for children with haemophilia.

Cost-utility analysis of primary prophylaxis versus treatment on-demand for individuals with severe haemophilia

OBJECTIVE

To assess the cost effectiveness of primary prophylaxis with clotting factor instead of treatment following a bleed (on-demand) for individuals with severe haemophilia.

DESIGN

Different data sources on the clinical effects and costs of treatments were combined using a Markov model.

SETTING

English treatment centres.

PERSPECTIVE

UK societal.

PARTICIPANTS

Hypothetical cohorts of 100 individuals with severe haemophilia A or B or severe von Willebrands disease.

INTERVENTIONS

Primary prophylaxis treatment on-demand with clotting factor.

OUTCOME MEASURES

Costs, quality-adjusted life-years (QALYs) and incremental cost per QALY in UK pounds ( pound, 1999/2000 values).

RESULTS

The baseline results showed that treating individuals with severe haemophilia A/severe von Willebrands disease or severe haemophilia B with primary prophylaxis instead of treatment on-demand cost an additional pound 46500 and pound 8600 per QALY gained, respectively. However, the results were extremely sensitive to a number of factors including the clotting factor unit cost, the time between prophylactic doses and the discount rate.

CONCLUSIONS

Despite the high costs of treatment, primary prophylaxis was cost effective compared with treatment on-demand in some scenarios. Primary prophylaxis is more likely to be cost effective for individuals with severe haemophilia B compared with individuals with severe haemophilia A/severe von Willebrands disease. Further research is required to assess the relationship between methods of clotting factor infusion and health-related quality-of-life.

Complications of central venous catheters in patients with haemophilia and inhibitors

We report our clinical experience with central venous catheters (CVCs) in 15 patients with haemophilia who, in total, had 34 catheters inserted. Eighteen devices were Hickman, six were Port-A-Cath and 10 were nontunnelled catheters (one Quinton, seven antecubital, one jugular and one subclavian vein access). All patients had factor VIII/IX inhibitors at the time of insertion. The mean age at operation was 8.8 years (range 16 months-39 years). Eight of the 15 patients (26/34 implanted catheters, 76%) presented some kind of complication. Pericatheter bleeding during the postoperative period affected a total of seven CVCs (7/34, 20%) in six patients, which required substitutive treatment for several days. Infection was reported in 15 of the CVCs (15/34, 44%), and four of these (4/15, 26%) had more than one episode, with a mean of 1.4 infection episodes per catheter (21/15). The infection rate was 0.2 infections per 1000 patient days or 0.1 per 1000 catheter days. Despite the usefulness of CVCs in haemophilic patients, the high incidence of complications requires careful assessment of the type of device as well as continuous surveillance.

Catheter-related deep venous thrombosis in children with hemophilia

Central venous catheters (CVCs) are a common adjunct to hemophilia therapy, but the risk of CVC-related deep venous thrombosis (DVT) in hemophiliacs is not well defined. In a previous study, 13 patients with CVCs had no radiographic evidence of DVT. However, recent abstracts and case studies demonstrate that DVT does occur. Therefore, this study sought to determine the frequency of DVT in children with hemophilia and long-term CVCs and to correlate venographic findings with clinical features. All hemophilia patients with tunneled subclavian CVCs in place for 12 months or more were candidates for evaluation. Patients were examined for physical signs of DVT and questioned about catheter dysfunction. Contrast venograms were obtained to identify DVT. Fifteen boys with severe hemophilia were evaluated, including 9 from the initially studied group of 13. Eight patients had evidence of DVT, 5 of whom previously had normal venograms. Five of 15 patients had clinical problems related to the CVC, all of whom had DVT. Four of 15 patients had suggestive physical signs; 3 had DVT. The mean duration of catheter placement for all patients was 57.5 months (range, 12-102 months). For patients with DVT, the mean duration was 66.6 +/- 7.5 months, compared to 49.5 +/- 7.2 months for patients without DVT (P =.06). No patient whose CVC was in place fewer than 48 months had an abnormal venogram. Many hemophilia patients with CVCs develop DVT of the upper venous system, and the risk increases with duration of catheter placement.

Central venous access devices in children with congenital coagulation disorders: complications and long-term outcome

Reliable venous access is essential to facilitate the administration of prophylactic factor concentrate or blood products in children with congenital coagulation disorders and immune tolerance therapy (ITT) regimens in those who develop high responding inhibitors. Poor venous access is even more problematic in very young children, the vast majority of whom will require the insertion of central venous access devices (CVADs). Previous studies have suggested that infection rates are low and that there are few long-term complications associated with CVAD usage. We have reviewed 86 CVADs that have been inserted, since 1988, in 58 children with congenital bleeding disorders, aged 6 d to 16.5 years, attending Great Ormond Street Hospital, London, and the National Children's Hospital, Dublin. The devices have remained in situ for 2 weeks to 92 months (median 22.5 months). Early (0-2 weeks) complications of CVAD insertion included nine bleeding episodes, one extravasation of factor concentrate, three allergic reactions to factor concentrate and five catheter infections. Overall, CVAD infection was the commonest problem encountered, with 52 devices (60%) becoming infected. Twenty-seven CVADs (31%) required removal. Infection rates in children without inhibitors (29/68) were 1/20 patient-months or 1. 6 infections/1000 patient-days, but infection rates for those with inhibitors were 1/8.5 patient-months or 4.3/1000 patient-days. Staphylococcus epidermidis was the predominant organism (25/52) isolated. Blockage of CVAD (four) and catheter disconnection (four) were the most frequently occurring non-infectious long-term complications. Skin erosion of the port was also seen in three children, in one child at 20 months, in one at 29 months and in one at 34 months after insertion. This study demonstrates a high CVAD infection rate and highlights the long-term complications of CVAD usage.

The use of central venous catheters (portacaths) in children with haemophilia

The experience with central venous implantable devices (portacaths) has been reviewed in children attending the Auckland Hospital Haemophilia Centre. Fourteen children had 23 portacaths inserted. Thirteen had severe Haemophilia A, of whom five had high responding inhibitors to factor VIII. All the children were HIV negative. Ages ranged from 4 months to 13 years at the time of initial placement and 12 were under 5 years. Indications for portacath placement included primary and secondary prophylaxis, induction of immune tolerance, prophylactic therapy post intracranial haemorrhage and poor venous access. Catheter-related infections occurred in 48% of cases. Staphylococcal species were the most common organisms isolated followed by gram-negative bacilli. 63% of the infections were successfully cleared with antibiotics. Haematoma formation occurred in 17% of catheters, primarily in patients who had high factor VIII inhibitor levels. Mechanical problems including blockage, leakage and extrusion of the portacath occurred less frequently (13%). The significant rate of infection in this immunocompetent population is consistent with other reports. Despite the obvious benefits of portacaths this complication is potentially serious and causes appreciable morbidity. In contrast, bleeding complication rates were relatively low.

Teaching parents advanced clinical skills

The management of haemophilia, in common with many other inherited, chronic disorders, has witnessed enormous advances and improvements. The quality of life enjoyed by children with haemophilia is excellent. To realize these benefits, however, expectations are placed on parents to administer intravenous treatment at home. The frequency of required treatment can be as often as alternate days. The role of implantable venous access devices has made venous access in young children at home a realistic procedure. This is a highly complex skill for the lay person to undertake, and comprehensive parental teaching and standardized written information are necessary. A teaching package has been created that commences with theoretical instruction and moves onto practical training. On-going assessment is then carried out at regular intervals in the home environment. Not only does this package provide a formal framework for instruction, it also facilitates emotional support for both the child and parents, which can be given in a planned manner. Nurses are professionally accountable for the information and teaching they give. This package documents the process of training undertaken and standardizes the level of information given. Thereby providing reassurance to nurses that they have fulfilled the professional requirements placed on them. Currently, there is no other source of information about implantable venous access devices for the lay carer. This package could be of value in other chronic conditions that incorporate an element of intravenous home care.

Use of recombinant factor VIIa (NovoSeven) in a haemophilia A patient with inhibitor in Kuwait

Development of inhibitors is a known complication in some haemophiliacs receiving coagulation factor replacement therapy. We report on the successful management of a young boy with haemophilia A with inhibitor using recombinant factor VIIa. We had failed to control bleeding in this patient following his circumcision, despite infusion with high doses of factor VIII concentrate for 2 weeks. Recombinant factor VIIa is a useful 'factor VIII bypassing agent' for the control of bleeding in patients with haemophilia A and B who develop inhibitors. We suggest that severely affected haemophiliacs should be absolved of ritual circumcision as a protective measure against what might become a life-threatening haemorrhage - especially in those with inhibitors.

Epidural placement in a patient with undiagnosed acquired haemophilia from factor VIII inhibitor

We report a case of acquired haemophilia that presented as continuous bleeding from an epidural insertion site in a previously asymptomatic parturient. Peripartum anaesthetic management of this rare medical emergency has not previously been reported and the difficulties associated with its treatment are discussed.

Central venous catheter-associated thrombosis in severe haemophilia

Significant subclavian vein thromboses associated with indwelling fully implanted (port-a-cath) devices are described in two boys with severe haemophilia A and factor VIII inhibitors. Investigations were prompted by prominent chest wall veins in one case, whereas the thrombosis was a chance finding in the other case during investigation of mechanical dislocation of the catheter tubing. Extensive collateral venous circulations were demonstrated by venography in both instances indicating that the thrombus had been present for some time. Possible contributing factors to the thromboses included desensitization therapy (both patients), high-dose FEIBA (in one patient) and use of lower doses of heparin for line flush than that recommended by some authors. Neither patient had a familial or non-familial predisposition to thrombosis.

A prospective clinical trial of implantable central venous access in children with haemophilia

To assess the risks associated with the use of central venous ports in children with haemophilia, 15 HIV-negative patients were prospectively evaluated. Port insertion was required for immune tolerance in two inhibitor patients and continuous prophylaxis in 13 patients with severe factor VIII deficiency, for whom surgery was covered with recombinant factor VIII (rFVIII), then given daily at home until day 6. One inhibitor patient (titre 7BU/ml) received high-dose rFVIII by continuous infusion until day 3, followed by an immune tolerance treatment scheme; the other (titre 12 BU/ml) was given recombinant activated factor VII by continuous infusion until day 7. After training on the use of the port, all patients continued their infusion programme at home. All ports remained in place for a median period of 413d (range 125-509). The median number of entries into the port was 184 (range 53-567). Port-site haematoma and infection occurred in one patient on day 7 when an inhibitor became detectable (titre 12 BU/ml). An infectious complication occurred in another patient after 310d. The port infection rate was 0-42 per 1000 patient-days (0.33 per 1000 entries into the port). This protocol for port placement with short hospitalization appears feasible and safe.

The use of the Port-A-Cath in children with haemophilia--a review

Port-A-Caths have been used increasingly in children with severe haemophilia. In non-inhibitor patients where Port-a-Caths were used to facilitate long-term prophylaxis, the infection rate is rather low and ranges in the various studies from 0 to 29%, with a median follow-up time of about 27 months. Patients that received the Port-A-Cath for the induction of immune tolerance (inhibitor patients) have a high infection rate of 50% to 83%. Although this percentage is high, good venous access is extremely important, especially in this group. The number of both inhibitor and non-inhibitor patients in the studies are very small, and a prospective survey is important to obtain more adequate data.

Implantable venous access devices in children with hemophilia: a report of low infection rates

OBJECTIVE

The objective of this study was to define the efficacy and complications of implantable venous access devices (IVADs) in children with hemophilia.

STUDY DESIGN

Records were reviewed on all patients with congenital blood coagulation disorders monitored at two children's hospitals in whom one or more central venous catheters had been placed.

RESULTS

Since 1989 external and implantable central venous catheters have been inserted to enhance venous access for regular factor concentrate infusion in 45 patients with hemophilia ranging in age from 8 months to 19.5 years (median 7.4 years); 37 patients had factor VIII deficiency and 8 factor IX deficiency. Hemorrhagic complications of catheter placement were infrequent and minor. In the 41 patients having one or more IVADs in place for a median of 31 months, only six episodes of bacteremia occurred in 5 patients during 44,070 days of follow-up. The overall rate of bacteremia complicating IVADs in these patients was 0.14 episodes per 1000 catheter days. Other catheter-related complications were uncommon. Catheters are still in place in 33 patients for a median of 32 months.

CONCLUSION

The low risk of infection and other complications associated with the use of IVADs makes the use of these devices attractive in the treatment of patients with hemophilia who require frequent venous access for factor concentrate infusions.