Anticoagulation Therapy In Children Research Articles

Self-Monitoring of Oral Anticoagulation Therapy in Children

This study aimed to investigate the accuracy of home International Normalized Ratio (INR) self-monitoring in pediatric patients on long-term oral anticoagulation therapy. Statistical and clinical agreement of INR values from capillary whole blood samples measured by 2 different portable prothrombin time monitors (CoaguChek S and XS) and venous blood samples measured by a laboratory coagulation analyzer were evaluated using the Bland-Altman analysis. Eighty-three INR comparisons (56 using the CoaguChek S and 27 using the CoaguChek XS) were obtained from 35 children aged 4 months to 18 years. Mean differences between venous and capillary INR values and their limits of agreement were –0.04 (–0.63 to 0.55) overall, 0.006 (–0.63 to 0.65) for the CoaguChek S and –0.13 (–0.57 to 0.31) for the CoaguChek XS. The Pearson correlation coefficients were 0.88 overall, 0.84 for the CoaguChek S and 0.95 for the CoaguChek XS. Expanded and narrow agreements for all patients were 97.6 and 94%, respectively. In conclusion, home INR self-monitoring is accurate for children requiring long-term oral anticoagulation therapy. Our data suggest that INR self-monitoring with the newer CoaguChek XS is more accurate than with the older CoaguChek S monitor.

Is Interrupted Inferior Vena Cava a Risk Factor in Cases of Bilateral Bidirectional Glenn?

Bilateral superior vena cava-to-pulmonary artery anastomoses are technically challenging. Bilateral superior vena cavae (SVCs) have been thought to be a risk factor for poor outcome in children needing single-ventricle palliation. The files of forty children who underwent bilateral cavopulmonary anastomoses (CPAs) were reviewed. Forty patients (31 male, 9 female) had bilateral bidirectional Glenn shunts in King Faisal Specialist Hospital and Research Center, Jeddah, in 7 years. Interrupted inferior vena cava (IIVC) was present in 8 patients. All IIVC cases featured a hypoplastic right ventricle. Twenty-four patients had a hypoplastic right ventricular morphology, and 16 patients had a hypoplastic left ventricular morphology. In single-ventricle anatomy, cases of a bilateral SVC are more often associated with an IIVC than a single SVC. Patients who undergo bilateral CPAs with an IIVC have a difficult early postoperative course. We should look for IIVC and either exclude or prove IIVC in cases of bilateral SVCs. Postoperative anticoagulation therapy in children with bilateral CPAs is important but should be investigated further.

Point-of-care monitoring of oral anticoagulation therapy in children

Point-of-care (POC) monitoring of oral anticoagulation has been widely adopted in both paediatric and adult patients. A new POC system, the CoaguChek XS has recently been developed to measure the international normalised ratio (INR) and may offer significant advantages. The CoaguChek XS utilises a new method of electrochemical clot detection based on thrombin generation. This system has not been previously evaluated in children with reference to the laboratory gold standard, the prothrombin time using reference thromboplastin. It was the objective to compare values obtained by the CoaguChek XS system with both the venous INR and the gold standard for anticoagulant monitoring, prothrombin time with reference thromboplastin (rTF/95). To evaluate the impact of testing using the CoaguChek XS on clinical anticoagulant dosing decisions. Fifty paired venous INR and capillary CoaguChek XS results were obtained from 31 children (aged up to 16 years). The laboratory gold standard, a manual prothrombin time with reference thromboplastin (rTF/95) was additionally performed on 26 samples. Correlation between the CoaguChek XS result and the venous INR was r = 0.810. Agreement between the CoaguChek XS result and the reference INR was shown to be higher (r=0.95), in the subset analysed by this method. Correlation between the venous INR and reference INR was r=0.90. Despite changes to the methodology of testing with the CoaguChek XS POC monitoring system, the accuracy of this method when compared with both the venous INR and gold standard reference INR was satisfactory. This resulted in infrequent changes to clinical decision making regarding anticoagulation.

Developing Educational Materials to Facilitate Adherence: Pediatric Thrombosis as a Case Illustration

Developing Educational Materials to Facilitate Adherence: Pediatric Thrombosis as a Case Illustration

Point-of-care monitoring of anticoagulant therapy in paediatric patients

Increased numbers of children with congenital heart disease are requiring anticoagulant therapy, as many of the medical and surgical interventions aimed at curing or palliating cardiac disease are associated with an increased risk of thromboembolic complications. The prospect of managing anticoagulant therapy in children presents several unique challenges. This article provides practical guidance in managing anticoagulant therapy in children through summarizing key principles that assist in managing anticoagulant therapy in children with congenital heart disease. Monitoring requirements of oral anticoagulant and low molecular weight heparin therapy in children are reviewed along with management of associated adverse events, treatment failures, and recommendations for patient education relating to anticoagulation and its influence on outcomes.

Home INR monitoring of oral anticoagulant therapy in children using the CoaguChek™ S point-of-care monitor and a robust education program

Introduction Management strategies such as self-monitoring of anticoagulant therapy have been reported with increased frequency. Whilst patient education is frequently mentioned, details regarding the educational interventions employed are scarce. This study aimed to improve the outcomes of home monitoring of warfarin therapy in children through the development and implementation of a robust intervention, based upon the PRECEDE model of education. Materials and methods Participating parents had to complete an intensive education and training program. After demonstrating practical and theoretical competency, parents commenced home monitoring. Every second scheduled home INR (H-INR) required a paired INR on the same day, obtained by a trained pathology collector (C-INR). Demographic and statistical outcome data was collected. Results Parental understanding of warfarin therapy improved significantly following the educational intervention ( p < 0.0001). 65.5% of H-INRs and 64.4% of C-INRs were within the target range (ns). Lin's correlation coefficient between H-INRs and C-INRs was 0.949. There were no warfarin-related adverse events. Conclusion This study demonstrated a significant improvement in parental knowledge following participation in a robust educational intervention. Furthermore, compared to previous reports in children, a greater level of correlation between home and hospital-based INRs was achieved by participating parents. The use of similar educational interventions may serve to improve the outcomes of similar management strategies.

Reply to rebuttal: A problem of calibration in the paper ‘Point of care monitoring of oral anticoagulant therapy in children’

Replytorebuttal:Aproblem of calibrationinthe paper ‘Pointofcaremonitoringof oral anticoagulanttherapy in children ’ -

Rebuttal: A problem of calibration in the paper ‘Point of care monitoring of oral anticoagulant therapy in children’

Rebuttal:A problem of calibrationin thepaper ‘Point of care monitoring of oral anticoagulant therapyin children ’ -

Anticoagulation therapy in children.

Thromboembolic disease (TED) is increasingly recognized as a major cause of morbidity and mortality in tertiary pediatrics. Children younger than 1 year of age and teenage girls are at greatest risk of thromboembolism. Although anticoagulation therapy is the treatment of choice for TED, the treatment strategy is often difficult, especially in children. Treatment relies largely on anticoagulation with heparin and warfarin. Recommendations for antithrombotic therapy in children have been loosely extrapolated from recommendations for adults; however, it is likely that optimal treatment of children with TED differs from adults because of important ontogenic features of hemostasis that affect both the pathophysiology of the thrombotic processes and the response to antithrombotic agents. Until recently, the primary treatment for TED has been unfractionated heparin (UFH) in conjunction with warfarin. Warfarin, the most commonly used oral anticoagulant, acts through inhibition of the vitamin K-dependent transcarboxylation reactions that convert precursors of clotting factors into their active form. Appropriate use of UFH and warfarin requires close patient monitoring and dosage adjustments to ensure tolerability and efficacy. In recent years, low molecular weight heparins (LMWH) have become available as alternatives to UFH and warfarin, for both the prevention and treatment of TED. Potentially, LMWH have significant advantages. They have superior pharmacokinetics, which results in minimal laboratory monitoring, offering important benefits to children with poor venous access. Based on available data, LMWHs are at least as effective and well tolerated as UFH, and are more convenient. Although LMWHs are more expensive than UFH, the expense is likely to be offset by savings from a reduced hospital stay.

Anticoagulation therapy in children.

Thromboembolic events (TEs) in children are rare but are becoming a recognized cause of morbidity and mortality, particularly in children with serious underlying primary conditions such as congenital heart disease, cancer, or prematurity. Neonates, infants, and adolescents are most at risk for developing TEs among children, and the presence of a central venous line or intra-arterial catheter is the most significant risk factor for TEs in children. Hemostatic differences between children and adults affect both the pathophysiology of the thrombotic process and the response to anticoagulant therapy. In this article, we focus on the impact of the developmental hemostatic system on responses to anticoagulants in children. The most commonly used anticoagulants in children are unfractionated heparin, low-molecular-weight heparins, and warfarin. Minimal experience exists with the use of the new antithrombotic agents in children. As the anticoagulant treatment used for TEs in children is largely adopted from clinical trials performed in adult populations, well-designed prospective trials are required to establish the optimal therapy for children with TEs.

Anticoagulation of children undergoing cardiopulmonary bypass is overestimated by current monitoring techniques.

Children who undergo cardiopulmonary bypass (CPB) are proportionally more hemodiluted than adults who undergo CPB. Current methods of monitoring high-dose heparin sulfate anticoagulation are dependent on fibrinogen level. Because of the decreased fibrinogen levels in children, current methods of monitoring heparin anticoagulation overestimate their level of anticoagulation. Prospective controlled trial. Production of thrombin (adequacy of anticoagulation). Children and adults undergoing cardiac surgery who received CPB were anticoagulated in the standard fashion as directed by activated clotting time (ACT) results. Each subject had blood sampled at baseline; heparinization; start of the CPB; CPB at 30, 60, and 90 minutes; and at termination of CPB. Samples were used to assess anticoagulation with the Heparin Management Test (less dependent on fibrinogen level than ACT). We also assessed 2 subclinical markers of thrombosis, thrombin-antithrombin complexes and prothrombin fragment F1.2; a marker of procoagulant reserve, fibrinogen; the natural antithrombotic, antithrombin; and heparin concentration. Ten children and 10 adults completed the study. Children had lower fibrinogen levels than adults throughout CPB (P<.05). All adults had both therapeutic ACT and Heparin Management Test levels measured throughout CPB. Although children had therapeutic ACT levels, their Heparin Management Test levels were subtherapeutic while undergoing CPB. The children had significantly higher thrombin-antithrombin complexes and prothrombin fragment F1.2 than adults, indicating ongoing thrombin production (P<.01). The increases in thrombin-antithrombin complexes and prothrombin fragment F1.2 in children were inversely proportional to their weight. Children undergoing CPB with heparin dosing adjusted to optimize the ACT manifest inadequate anticoagulation (ongoing thrombin formation). High-dose heparin anticoagulation therapy in children undergoing CPB should be directed by tests (like the Heparin Management Test) that are less dependent on fibrinogen level than ACT.

Lateral dural sinus thrombosis in childhood.

To present etiology, diagnosis, and treatment of dural sinus thrombosis (DST) in children. To discuss the diagnostic role of contrast-enhanced computed tomography (CECT) and to evaluate the controversial treatment modalities of anticoagulation, surgical drainage of the infected sinus, and ligation of the internal jugular vein (IJV). Retrospective chart review and analysis of computed tomography (CT) scans and follow-up visits to document the clinical outcome. Between 1986 and 1996, CT scans of 15 children revealed DST. These patients were further investigated. The etiology could be divided in three groups: group A, infection (6); group B, trauma (6); and group C, coagulation disorders. There were neither symptoms nor clinical findings specifically related to DST but rather, these were related to the underlying disease or condition (otitis media, skull base fractures). Diagnosis was made by CECT in all cases. Fusobacterium necrophorum was found in 4 of 6 patients in group A. Early mastoidectomy with incision and drainage of the thrombosed sigmoid sinus was performed in patients in group A. Postoperative intravenous (IV) heparin was given; however, no ligation of the IJV became necessary. In all patients in group C, protein C or protein S deficiency, or both, was detected. CECT with adequate window-level settings allows the diagnosis of a DST with high sensitivity. Treatment of choice for septic DST consists of administration of antibiotics and early surgical drainage. We recommend anticoagulation therapy in children with septic DST during their hospitalization.

Indications and drugs for anticoagulation therapy in children

The indications for using anticoagulants in children are reviewed. These include venous thromboembolic disease, thrombosis associated with central venous lines, inherited conditions, arterial thromboembolic disease and umbilical catheterization. The anticoagulants presently available for paediatric use consist of heparin and oral agents including low molecular weight heparin (LMWH). The problems associated with their use in children are examined and potential advantages described. Increasing numbers of children are now requiring anticoagulant therapy and the potential advantages of LMWHs makes it imperative that randomized, controlled trials be carried out in children in prophylactic as well as therapeutic situations.

Anticoagulant therapy in children with prosthetic valves

The purpose of this study was to evaluate the effectiveness and complications of several types of anticoagulant therapy in children with prosthetic valves. During a 7-year period ending April 1985, 130 children aged 1 to 19 years underwent left-sided valve replacement. Operative mortality was 3%, 5%, and 9%, respectively, for aortic, mitral, and aortic and mitral valve replacement. Among the 123 survivors, 32 (26%) had had aortic, 71 (58%) had had mitral, and 20 (16%) had had aortic and mitral valve replacement. Follow-up ranged from 2 months to 8.2 years, a total of 544 patient-years. The survivors were divided into three groups based on anticoagulant treatment: warfarin sodium, aspirin plus dipyridamole, and no anticoagulants. Among the patients who had aortic valve replacement, thromboembolic complications developed in 2.5% ( 2.5 / 100 patient-years) of the aspirin plus dipyridamole group and 5% of the group given no anticoagulants. Only the warfarin group (4%) experienced bleeding complications. Among the patients having mitral valve replacement, thromboembolic complications developed in 4% of the warfarin group, 3% of the aspirin plus dipyridamole group, and 11% of the no anticoagulant group. In addition, 2% of patients in the warfarin group experienced severe bleeding. Two fatal cerebrovascular accidents occurred, both in the aspirin plus dipyridamole group. Patients who received a mitral heterograft were not prescribed any anticoagulant medications, and no thromboembolic complications developed. Among patients having doable-valve replacement, complications developed in 5% of the warfarin group and 27% of the group given no anticoagulants. Based on these data, aspirin plus dipyridamole appears adequate for patients having aortic valve replacement, whereas warfarin is required in patients having double-valve replacement. Patients having mitral valve replacement with heterografts require no anticoagulation, but those with mechanical valves may need warfarin anticoagulation. There are not adequate data to evaluate the safety and efficacy of the combined use of warfarin and a platelet-inhibiting drug in children.

Anticoagulation therapy in children with mechanical prosthetic cardiac valves

From 1980 through 1984, 28 children younger than 19 years (mean 7.9) underwent cardiac valve replacement with 30 mechanical prostheses. Patients were followed for a total of 471 months (mean 15.7) and received either warfarin (mean 0.16 mg/kg/day) or acetylsalicylic acid and dipyridamole (mean 6.1 and 1.9 mg/kg/day, respectively) as thromboembolism prophylaxis. The frequency and incidence of thromboembolism and hemorrhage were compared. Warfarin-treated patients were at increased risk of hemorrhage (5 of 20 [25%], or 22 per 100 patient years, vs 0 of 10 [0%], or 0 per 100 patient-years, p < 0.05). Three of the 5 hemorrhagic episodes were mild, and in no case was hemorrhage life-threatening. Patients who did not receive warfarin had a greater risk of thromboembolism (2 of 10 [20%], or 12 per 100 patient-years, vs 0 of 20 [0%], or 0 per 100 patient-years, p < 0.05). Both episodes of thromboembolism were life-threatening and necessitated emergency valve replacement. Although warfarin is associated with greater risk of hemorrhage than is acetylsalicylic acid and dipyridamole, warfarin is better than antiplatelet drugs in thromboembolism prophylaxis and is indicated for anticoagulation therapy in children with mechanical cardiac prostheses.