Continuous infusion of factor concentrates in children with haemophilia A in comparison with bolus injections

Managing Relevant Clinical Conditions of Hemophilia A/B Patients

The Medical Directors of nine Italian Hemophilia Centers reviewed and discussed the key issues concerning the replacement therapy of hemophilia patients during a one-day consensus conference held in Rome one year ago. Particular attention was paid to the replacement therapy needed for surgery using continuous infusion (CI) versus bolus injection (BI) of standard and extended half-life Factor VIII (FVIII) concentrates in severe hemophilia A patients. Among the side effects, the risk of development of neutralizing antibodies (inhibitors) and thromboembolic complications was addressed. The specific needs of mild hemophilia A patients were described, as well as the usage of bypassing agents to treat patients with high-responding inhibitors. Young hemophilia A patients may take significant advantages from primary prophylaxis three times or twice weekly, even with standard half-life (SHL) rFVIII concentrates. Patients affected by severe hemophilia B probably have a less severe clinical phenotype than severe hemophilia A patients, and in about 30% of cases may undergo weekly prophylaxis with an rFIX SHL concentrate. The prevalence of missense mutations in 55% of severe hemophilia B patients allows the synthesis of a partially changed FIX molecule that can play some hemostatic role at the level of endothelial cells or the subendothelial matrix. The flow back of infused rFIX from the extravascular to the plasma compartment allows a very long half-life of about 30 h in some hemophilia B patients. Once weekly, prophylaxis can assure a superior quality of life in a large severe or moderate hemophilia B population. According to the Italian registry of surgery, hemophilia B patients undergo joint replacement by arthroplasty less frequently than hemophilia A patients. Finally, the relationships between FVIII/IX genotypes and the pharmacokinetics of clotting factor concentrates have been investigated.

Pharmacokinetics of perioperative FVIII in adult patients with haemophilia A: An external validation and development of an alternative population pharmacokinetic model

INTRODUCTION

Haemophilia A patients require perioperative clotting factor replacement to limit excessive bleeding. Weight-based dosing of Factor VIII (FVIII) does not account for inter-individual pharmacokinetic (PK) variability, and may lead to suboptimal FVIII exposure.

AIM

To perform an external validation of a previously developed population PK (popPK) model of perioperative FVIII in haemophilia A patients.

METHODS

A retrospective chart review identified perioperative haemophilia A patients at the University of North Carolina (UNC) between April 2014 and November 2019. Patient data was used to externally validate a previously published popPK model proposed by Hazendonk. Based on these validation results, a modified popPK model was developed to characterize FVIII PK in our patients. Dosing simulations were performed using this model to compare FVIII target attainment between intermittent bolus (IB) and continuous infusion (CI) administration methods.

RESULTS

A total of 521 FVIII concentrations, drawn from 34 patients, were analysed. Validation analyses revealed that the Hazendonk model did not fully capture FVIII PK in the UNC cohort. Therefore, a modified one-compartment model, with weight and age as covariates on clearance (CL), was developed. Dosing simulations revealed that CI resulted in improved target attainment by 16%, with reduced overall FVIII usage by 58 IU/kg, compared to IB.

CONCLUSION

External validation revealed a previously published popPK model of FVIII did not adequately characterize UNC patients, likely due to differences in patient populations. Future prospective studies are needed to evaluate our model prior to implementation into clinical practice.

Perioperative pharmacokinetic-guided factor VIII concentrate dosing in haemophilia (OPTI-CLOT trial): an open-label, multicentre, randomised, controlled trial

BACKGROUND

Dosing of replacement therapy with factor VIII concentrate in patients with haemophilia A in the perioperative setting is challenging. Underdosing and overdosing of factor VIII concentrate should be avoided to minimise risk of perioperative bleeding and treatment costs. We hypothesised that dosing of factor VIII concentrate on the basis of a patient's pharmacokinetic profile instead of bodyweight, which is standard treatment, would reduce factor VIII consumption and improve the accuracy of attained factor VIII levels.

METHODS

In this open-label, multicentre, randomised, controlled trial (OPTI-CLOT), patients were recruited from nine centres in Rotterdam, Groningen, Utrecht, Nijmegen, The Hague, Leiden, Amsterdam, Eindhoven, and Maastricht in The Netherlands. Eligible patients were aged 12 years or older with severe or moderate haemophilia A (severe haemophilia was defined as factor VIII concentrations of <0·01 IU/mL, and moderate haemophilia as 0·01-0·05 IU/mL), without factor VIII inhibitors, and planned for elective low or medium risk surgery as defined by surgical risk score. Patients were randomly assigned (1:1) using a web-based randomisation system and treatment minimisation, stratified by method of administration of factor VIII concentrate (continuous infusion vs bolus administration) and risk level of surgery (low and medium risk surgery), to the pharmacokinetic-guided or standard treatment group. The primary endpoint was total amount of infused factor VIII concentrate (IU per kg bodyweight) during perioperative period (from day of surgery up to 14 days after surgery). Analysis was by intention to treat and the safety analysis population comprised all participants who underwent surgery with factor VIII concentrate. This study is registered with the Netherlands Trial Registry, NL3955, and is now closed to accrual.

FINDINGS

Between May 1, 2014, and March 1, 2020, 98 patients were assessed for eligibility and 66 were enrolled in the trial and randomly assigned to the pharmacokinetic-guided treatment group (34 [52%]) or the standard treatment group (32 [48%]). Median age was 49·1 years (IQR 35·0 to 62·1) and all participants were male. No difference was seen in consumption of factor VIII concentrate during the perioperative period between groups (mean consumption of 365 IU/kg [SD 202] in pharmacokinetic-guided treatment group vs 379 IU/kg [202] in standard treatment group; adjusted difference -6 IU/kg [95% CI -88 to 100]). Postoperative bleeding occurred in six (18%) of 34 patients in the pharmacokinetic-guided treatment group and three (9%) of 32 in the standard treatment group. One grade 4 postoperative bleeding event occurred, which was in one (3%) patient in the standard treatment group. No treatment-related deaths occurred.

INTERPRETATION

Although perioperative pharmacokinetic-guided dosing is safe, it leads to similar perioperative factor VIII consumption when compared with standard treatment. However, pharmacokinetic-guided dosing showed an improvement in obtaining factor VIII concentrations within the desired perioperative factor VIII range. These findings provide support to further investigation of pharmacokinetic-guided dosing in perioperative haemophilia care.

FUNDING

Dutch Research Council (NWO)-ZonMw and Takeda.

Results of a randomized phase III/IV trial comparing intermittent bolus versus continuous infusion of antihaemophilic factor (recombinant) in adults with severe or moderately severe haemophilia A undergoing major orthopaedic surgery

Introduction

In patients with haemophilia A undergoing surgery, factor VIII (FVIII) replacement therapy by continuous infusion (CI) may offer an alternative to bolus infusion (BI).

Aim

To compare the perioperative haemostatic efficacy and safety of antihaemophilic factor (recombinant) (ADVATE^®; Baxalta US Inc., a Takeda company, Lexington, MA, USA) CI or BI administration.

Methods

In this multicentre, phase III/IV, controlled study (NCT00357656), 60 previously treated adult patients with severe or moderately severe disease undergoing elective unilateral major orthopaedic surgery (knee replacement, n = 48; hip surgery, n = 4; other, n = 8) requiring drain placement were randomized to receive antihaemophilic factor (recombinant) CI (n = 29) or BI (n = 31) through postoperative day 7. Primary outcome measure was cumulative packed red blood cell (PRBC)/blood volume in the drainage fluid within 24 h after surgery, used to establish non‐inferiority of CI to BI.

Results

CI:BI ratio of cumulative PRBC volume in the 24‐h drainage fluid was 0.92 (p‐value <.001 for non‐inferiority; 95% confidence interval, 0.82–1.05). Total antihaemophilic factor (recombinant) dose per kg body weight received in the combined trans‐ and postoperative periods was similar with CI and BI to maintain targeted FVIII levels during/after surgery. Treatment‐related adverse events (AEs) were reported in five patients treated by CI (eight events) and five treated by BI (six events), including two serious AEs in each arm.

Conclusion

CI administration of antihaemophilic factor (recombinant) is a viable alternative to BI in patients with haemophilia A undergoing major orthopaedic surgery, providing comparable efficacy and safety.

Successful Perioperative Management of Orthotopic Cardiac Transplantation in a Pediatric Patient With Concurrent Congenital von Willebrand Disease and Acquired von Willebrand Syndrome Using Recombinant von Willebrand Factor

Von Willebrand disease (VWD) is the most common bleeding disorder and reportedly affects 1:1,000 of the world's population. There are three subtypes of VWD characterized by a quantitative defect (types 1 and 3 VWD) or a qualitative defect (type 2 VWD). Type 1 VWD results in a partial deficiency of von Willebrand factor (VWF) and affects approximately 75% of individuals with VWD, whereas type 3 VWD results in a severe or complete deficiency of VWF. Individuals with type 2 VWD subtypes (types 2A, 2B, 2M, and 2N VWD) express a dysfunctional VWF protein that has impaired interactions with platelets or factor VIII. The majority of individuals with VWD have mild type 1 VWD and occasionally require bolus infusions of VWF for severe bleeding or major surgery. A subset of patients, especially those with type 2A or 3 VWD, may require more frequent VWF replacement or prophylaxis for refractory bleeding or bleeding prevention, respectively. Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that primarily occurs as a result of an underlying disease or other pathologic mechanism. Cases of AVWS associated with heart valve defects, left ventricular assist devices, or congenital cardiac disease result from high shear stress in the circulation that induces VWF unfolding and subsequent proteolysis of high-molecular-weight multimers by ADAMTS-13. In rare instances, plasma-derived factor VIII-containing VWF concentrates have been administered to individuals with AVWS for persistent or challenging bleeding events. In this case report, the hemostatic challenges and the perioperative management of cardiac transplantation surgery using a novel recombinant VWF product in a pediatric patient diagnosed with AVWS concomitant with congenital type 1 VWD are described. Written informed consent was obtained from the patient's mother for this case report. The diagnosis of congenital VWD remains a challenge because of multiple potential modifiers that can alter VWF laboratory results. Concurrent conditions, such as congenital heart disease and the rare secondary condition of AVWS, in addition to congenital VWD, can further affect interpretation of coagulation studies. This can result in delays in diagnosis, increase severity of the bleeding phenotype, and complicate hemostatic management in individuals at risk for bleeding and thrombosis. A multidisciplinary approach, including anesthesiologists, cardiologists, cardiovascular surgeons, hematologists, and pharmacists, is critical to achieving optimal patient outcomes, as highlighted in this case report. As diagnostic capabilities and understanding of VWD broaden, future studies evaluating alternative treatment approaches for individuals with various types of VWD would be of great benefit to the medical community.

Continuous infusion of recombinant activated factor VII: a review of data in congenital hemophilia with inhibitors and congenital factor VII deficiency

Introduction

Continuous infusion (CI) of clotting factors as a replacement therapy for perioperative hemostatic protection has been performed for many years, including with factors VIII and IX and recombinant activated factor VII (rFVIIa). This approach provides steady factor levels without requiring frequent administration of bolus doses.

Aim

To review safety, efficacy, and dosing data regarding CI of rFVIIa for hemostatic management of patients with congenital hemophilia with inhibitors (CHwI) or congenital factor VII deficiency (C7D).

Materials and methods

A literature review identified instances of CI of rFVIIa in patients with CHwI or C7D undergoing surgery or experiencing bleeding episodes. Data regarding safety, efficacy, and dosing were extracted.

Results

The safety and efficacy of 50 mcg/kg/h CI of rFVIIa following a 90 mcg/kg bolus injection, vs a standard bolus injection regimen, was reported for 24 patients with CHwI undergoing elective surgery in an open-label, randomized, Phase III trial. Efficacy was similar between CI and bolus injection groups at all postoperative time points assessed. Additionally, a postmarketing surveillance study reported effective (80%) and partially effective (20%) CI of rFVIIa in a Japanese cohort of ten patients with CHwI who underwent 15 surgical procedures. Finally, the safety and dosing of rFVIIa CI in 193 and 26 patients with CHwI and C7D, respectively, were reported in 11 prospective studies, 10 retrospective studies, and 30 case reports. No unexpected safety findings were reported.

Conclusion

rFVIIa CI has been performed safely and effectively in patients with CHwI and C7D undergoing surgery and during bleeding episodes in patients with CHwI.

Continuous infusion of simoctocog alfa in haemophilia A patients undergoing surgeries

INTRODUCTION

There are two major principles for coagulation factor replacement in the clinical management of surgical procedures in patients with haemophilia, repetitive bolus injections every 6-12 hours or administration of coagulation factor concentrates by continuous infusion.

AIM

The aim was to investigate the efficacy of simoctocog alfa (human-cl rhFVIII) delivered by continuous infusion for bleeding prophylaxis during surgery in patients with haemophilia A.

METHODS

We investigated the use of continuous infusion with simoctocog alfa in haemophilia A patients undergoing major surgical procedures at Oslo University Hospital from September 2015 to March 2018. The objectives were haemostatic outcome, in vivo recovery, stability over time at room temperature (3 days) and inhibitor development.

RESULTS

Simoctocog alfa demonstrated treatment success in terms of haemostatic efficacy in 100% of major surgeries used as CI: 87% (n=21) excellent; 13% (n=3) good. No erythrocyte transfusions were required in any patient, no adverse events occurred and no inhibitors developed. The product was stable for 3 days at room temperature without loss of activity. Mean in vivo recovery was 1.8 (0.3) (IU/mL/IU/kg).

CONCLUSION

Continuous infusion with simoctocog alfa was found to achieve good/excellent haemostatic efficacy in all procedures. No adverse events occurred and no inhibitors developed.

Continuous infusion of coagulation factor concentrates during intensive treatment

In clinical management of bleeds and surgical procedures in patients suffering from bleeding disorders either repetitive bolus injections (BI) or continuous infusion (CI) can be used for coagulation factor replacement. Continuous infusion seems to be an attractive route of administration and may be considered if replacement therapy is required for more than 3 days. The strongest argument favouring continuous infusion is its superiority in providing the patient with a safe and constant level of the deficient coagulation factor by balancing input with clearance. Furthermore, several studies have shown that coagulation factor consumption may be reduced by CI compared to repetitive bolus injections (BI) since unnecessary peaks of factor level are avoided. Concerns have been raised whether continuous infusion of coagulation concentrates is associated with an increased risk of developing inhibitors. However, available data have so far not shown an increased risk for inhibitor development in severe haemophilia patients with more than 50 exposure days of coagulation factor concentrates. Further, previously reported complications when using CI such as phlebitis at the infusion site and pump failure are nowadays very seldom seen when small amounts of heparin are added to the infusion bag, and increased quality of the pumps are available. Over the last decades, numerous reports have confirmed CI to be a safe and effective mode of coagulation factor replacement even in the most challenging surgical procedures, such as total joint arthroplasties.

A population pharmacokinetic model for perioperative dosing of factor VIII in hemophilia A patients

The role of pharmacokinetic-guided dosing of factor concentrates in hemophilia is currently a subject of debate and focuses on long-term prophylactic treatment. Few data are available on its impact in the perioperative period. In this study, a population pharmacokinetic model for currently registered factor VIII concentrates was developed for severe and moderate adult and pediatric hemophilia A patients (FVIII levels <0.05 IUmL^-1) undergoing elective, minor or major surgery. Retrospective data were collected on FVIII treatment, including timing and dosing, time point of FVIII sampling and all FVIII plasma concentrations achieved (trough, peak and steady state), brand of concentrate, as well as patients' and surgical characteristics. Population pharmacokinetic modeling was performed using non-linear mixed-effects modeling. Population pharmacokinetic parameters were estimated in 75 adults undergoing 140 surgeries (median age: 48 years; median weight: 80 kg) and 44 children undergoing 58 surgeries (median age: 4.3 years; median weight: 18.5 kg). Pharmacokinetic profiles were best described by a two-compartment model. Typical values for clearance, intercompartment clearance, central and peripheral volume were 0.15 L/h/68 kg, 0.16 L/h/68 kg, 2.81 L/68 kg and 1.90 L/68 kg. Interpatient variability in clearance and central volume was 37% and 27%. Clearance decreased with increasing age (P<0.01) and increased in cases with blood group O (26%; P<0.01). In addition, a minor decrease in clearance was observed when a major surgical procedure was performed (7%; P<0.01). The developed population model describes the perioperative pharmacokinetics of various FVIII concentrates, allowing individualization of perioperative FVIII therapy for severe and moderate hemophilia A patients by Bayesian adaptive dosing.

Perioperative treatment of hemophilia A patients: blood group O patients are at risk of bleeding complications

ESSENTIALS: Targeting of factor VIII values is a challenge during perioperative replacement therapy in hemophilia. This study aims to identify the extent and predictors of factor VIII underdosing and overdosing. Blood group O predicts underdosing and is associated with perioperative bleeding. To increase quality of care and cost-effectiveness of treatment, refining of dosing is obligatory.

SUMMARY

BACKGROUND

Perioperative administration of factor VIII (FVIII) concentrate in hemophilia A may result in both underdosing and overdosing, leading to respectively a risk of bleeding complications and unnecessary costs.

OBJECTIVES

This retrospective observational study aims to identify the extent and predictors of underdosing and overdosing in perioperative hemophilia A patients (FVIII levels < 0.05 IU mL(-1)).

PATIENTS AND METHODS

One hundred nineteen patients undergoing 198 elective, minor, or major surgical procedures were included (median age 40 years, median body weight 75 kg). Perioperative management was evaluated by quantification of perioperative infusion of FVIII concentrate and achieved FVIII levels. Predictors of underdosing and (excessive) overdosing were analyzed by logistic regression analysis. Excessive overdosing was defined as upper target level plus ≥ 0.20 IU mL(-1).

RESULTS

Depending on postoperative day, 7-45% of achieved FVIII levels were under and 33-75% were above predefined target ranges as stated by national guidelines. A potential reduction of FVIII consumption of 44% would have been attained if FVIII levels had been maintained within target ranges. Blood group O and major surgery were predictive of underdosing (odds ratio [OR] 6.3, 95% confidence interval [CI] 2.7-14.9; OR 3.3, 95% CI 1.4-7.9). Blood group O patients had more bleeding complications in comparison to patients with blood group non-O (OR 2.02, 95% CI 1.00-4.09). Patients with blood group non-O were at higher risk of overdosing (OR 1.5, 95% CI 1.1-1.9). Additionally, patients treated with bolus infusions were at higher risk of excessive overdosing (OR 1.8, 95% CI 1.3-2.4).

CONCLUSION

Quality of care and cost-effectiveness can be improved by refining of dosing strategies based on individual patient characteristics such as blood group and mode of infusion.

The "OPTI-CLOT" trial. A randomised controlled trial on periOperative PharmacokineTIc-guided dosing of CLOTting factor concentrate in haemophilia A

Haemophilia A is an X-linked inherited, rare bleeding disorder, caused by a deficiency of coagulation factor VIII (FVIII). Previous studies in prophylactic dosing have demonstrated that FVIII consumption can be significantly reduced by individualising dosing based on combined analysis of individual pharmacokinetic (PK) profiling and population PK data (Bayesian analysis). So far, no studies have been performed that address perioperative concentrate consumption using iterative PK-guided dosing based on a PK population model. The "OPTI-CLOT" trial is an open-label, prospective, multicentre randomised controlled superiority trial (RCT), aiming to detect a 25 % difference in perioperative FVIII concentrate consumption with iterative Bayesian PK-guided dosing in comparison to the standard dosing procedure. Sixty haemophilia A patients ≥ 12 years of age, with FVIII plasma levels ≤ 0.05 IUml(-1) will be included requiring FVIII replacement therapy administered either by continuous or bolus infusion for an elective, low or medium risk surgical procedure. The proposed study aims to investigate a novel perioperative iterative PK-guided dosing strategy, based on a recently constructed perioperative PK population model. This model will potentially decrease underdosing and overdosing of clotting factor concentrate and is expected to overall reduce FVIII consumption by minimally 25 %. Moreover, participating hospitals will gain experience with PK-guided dosing, facilitating future implementation of this intervention which is expected to optimise current care and reduce costs of treatment.

Progress of in vitro factor VIII coagulant activity from 0 to 8 hours after reconstitution

Background

Continuous infusion of factor VIII (FVIII) is a more cost-effective method for treating hemophilia A than intermittent bolus injection. However, there is currently no specific data in Korea about the progress of in vitro FVIII coagulant activity (FVIII:C) after reconstitution from its lyophilized form.

Methods

Three commercial FVIII concentrate products (two recombinant FVIII and one plasma-derived) were used. In vitro FVIII:C was measured at 0, 2, 4, 6, and 8 hours following reconstitution in both the indoor light-exposed and light-shielded groups.

Results

For the three drugs, in vitro FVIII:C decreased over the 8 hours following reconstitution (P<0.001). The decline of FVIII:C was linear (P<0.001). In vitro FVIII:C for the indoor light-exposed groups was 95.3±1.9% and 90.6±2.5% after 4 and 8 hours following reconstitution, respectively, compared to baseline activity. In the light-shielded group, FVIII:C was 95.4±1.1% and 90.9±1.7% of the baseline activity after 4 and 8 hours, respectively. There was no statistical difference between FVIII:C in the indoor light-exposed and light-shielded groups (P=0.849).

Conclusion

In vitro FVIII:C decreased after reconstitution, but activity was maintained at over 90% of the baseline value during 8 hours. Exposure to indoor light did not accelerate the loss of FVIII:C over the experimental time. This result indicates that CI with FVIII is available in 8-hour intervals, with no indoor light-exposure precautions needed.

Beriate® P in the treatment of patients with haemophilia A: results of a long-term pharmacovigilance study

BACKGROUND

The German Beriate(®) P pharmacovigilance study started in 2003 and is planned to run until December 2013.

MATERIALS AND METHODS

This analysis included data from 84 haemophilia A patients treated with the high-purity, plasma-derived coagulation factor VIII concentrate Beriate(®) P. Prior to study start, 69 of the 80 patients for whom data were available had received previous treatment with Beriate(®) P (mean treatment period 7.1 ± 5.4 years). The mean study duration from the start of pharmacovigilance was 43.3 ± 30.3 months (median 43.5 months; range 0-101.9months). The most common treatment at the last visit was prophylaxis (65.7% of patients), which was most commonly administered at a frequency of three infusions/week in 47.3% of patients.

RESULTS

Most patients experienced up to six minor bleeds/year. For 1,311 bleeding episodes, a median of one infusion/bleed was administered (mean 2.8 ± 4.7; range 0-83). The clinical response to Beriate(®) P was rated "excellent"/"good" in 94% of 32 visits of patients with major bleeding. The clinical response for patients with minor bleeding was rated "excellent"/"good" in 98.5% of 377 visits. One clinically relevant inhibitor in a previously untreated patient was documented during the study course. There were no reports of virus transmissions suspected to be caused by Beriate(®) P prior to the study start or during the study.

CONCLUSIONS

These findings confirm the excellent efficacy, safety, and tolerability of Beriate(®) P in the treatment of a wide spectrum of previously untreated patients up to adult patients with haemophilia A.

Non-genetic risk factors and the development of inhibitors in haemophilia: a comprehensive review and consensus report

SUMMARY

The development of inhibitors to the infused factor in patients with haemophilia is a serious clinical problem. Recent evidence suggests that alongside the strong genetic contribution to inhibitor formation, there are a number of non-genetic factors--perceived by the immune system as danger signals--which promote formation of inhibitors. This study provides a comprehensive review of clinical studies relating to these factors and also presents a survey of opinion concerning their importance and clinical influence, conducted among the members of the European Haemophilia Treatment Standardisation Board (EHTSB). Taken together, this information highlights the lack of robust data concerning the influence of several non-genetic risk factors on inhibitor development, and an urgent need for prospective, well-conducted studies that adhere to recommendations made by the European Medicines Agency (EMEA) for studying inhibitors. Based on current literature, the EHTSB formulated consensus recommendations. It is desirable to minimize intensive treatment wherever possible, given the clinical situation. Prophylaxis should be offered to all children, although we still need to determine optimal dosing with respect to inhibitor development, and age for starting treatment. Vaccinations should be given subcutaneously and concomitant factor concentrate infusions avoided. According to the board, there is no evidence in the literature supporting suggestions that the type of concentrate influences inhibitor risk; but all patients should be monitored during their first exposures. Furthermore, there is no evidence to support an association between pregnancy-related issues, breast feeding and treatment-related factors (e.g. route of administration, or use of blood components) and inhibitor development.

Haemophilia in the first years of life

Surgery in infants and young children with haemophilia, when preceded by accurate diagnosis and accompanied by safe and effective factor prophylaxis, is not associated with a significant risk of haemorrhage. Haemophilic newborns undergoing circumcision or major surgery prior to diagnosis and in the absence of appropriate haemostatic prophylaxis remain as a concern. Inhibitor development has replaced haemorrhage as the major surgical complication in the developed world, largely because of the intensity of treatment used to secure haemostasis. For that reason only, essential surgery should be performed. Intracranial haemorrhage (ICH) during the neonatal period affects 3.5-4.0% of all haemophilia boys in countries with a good standard of health care, which is considerably (40-80 times) higher than expected in the normal population. Because of the high frequency of sporadic cases, ICH in the neonatal period can only be partially prevented by improved carrier diagnosis and counselling. Infections and thrombosis are the major serious complications of central venous lines. Large differences are seen in the frequency of these complications, the most plausible explanations are probably related to the protocol used for device care, the quality of education and the compliance of the users, an issue addressed in an on-going study.

Continuous infusion of coagulation factors: current opinion

PURPOSE OF REVIEW

To review the most recent reports on continuous infusion of coagulation factors, focusing on the current issues relating to this mode of therapy.

RECENT FINDINGS

Continuous infusion has been extensively used as an alternative to intermittent bolus factor replacement since the 1990s. To date, more than 100 reports comprising more than 800 continuous infusion treatments in various clinical situations have been published, with an increase in the current utilization of recombinant coagulation factors. An excellent hemostatic efficacy of continuous infusion has been reported. Continuous infusion protocols, however, still vary widely in terms of the different hemostatic levels targeted, dosage regimens, modes of continuous infusion and duration of therapy, which obviously result in variations in the cost-effectiveness reported by different centers.

SUMMARY

Continuous infusion has been shown to be a safe and cost-effective mode of replacement for treatment of hemophilia. The lack of evidence-based information on the hemostatic levels to be maintained in specific clinical situations, and recent concerns regarding the development of inhibitors, particularly in patients with mild hemophilia treated with continuous infusion, need to be addressed by prospective, randomized studies that compare traditional intermittent injections and the continuous infusion mode of factor replacement.