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Aim of the study: We aimed to discuss our experience in management of children with extra-hepatic portal vein thrombosis (EHPVT). Material and methods: This retrospective cohort study included 62 children with EHPVT. All patients' records were reviewed. The patients' socio-demographic data, post-natal history, disease presentation and clinical examination were collected. Data from laboratory investigations - complete blood count, liver function tests, renal function tests, abdominal ultrasound/Doppler studies, upper endoscopic findings and treatment regimens - were collected whenever available. Results: Of the 62 patients, 62.9% were male and 37.1% were female. The mean age at disease presentation was 3.5 ±2.7 years. The main initial clinical presentation of the disease was hematemesis and/or melena (30 cases; 48.4%). History of umbilical catheterization (UVC) was present in 60% of cases. The thrombophilia profile was assessed in 17 patients, of whom 12 (70.6%) were found to have a coagulation disorder. Splenomegaly was present in 91.7% of the patients. Hematological abnormalities in the form of cytopenias were present in most cases. Ultrasound revealed the presence of collaterals in 76.2%. Upper endoscopy showed the presence of varices in 45 cases, all of which needed endoscopic intervention, while in 11 cases the varices were either low grade or absent and thus were subjected only to medical treatment with propranolol and 6 cases were lost to follow-up. Splenectomy was done in only one case and 2 cases underwent the Rex operation. Conclusions: Variceal bleeding is the most common clinical presentation of EHPVT in children. UVC is still the main etiological factor of EHPVT in our cohort especially with presence of thrombophilic disorder. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study is to present clinical, imaging and laboratory findings of pediatric cerebral venous sinus thrombosis (CVST), and to evaluate any relationship between the platelet indices and CVST in children. Material and Methods: Clinical, laboratory and imaging findings of fifteen children with detected CVST on MRI examinations were recorded retrospectively. Fifteen controls were included in the study. All patients and controls were evaluated and platelet indices including; MPV, PDW, PC and MPV/plt ratio were compared. Results: There was no difference in age and gender distribution between patients and controls. The most common symptom in patients with CVST was headache and fever. Platelet count, PDW, MPV and MPV/plt ratio were slightly higher in controls, however there was no significant difference between two groups (p=0.2, p=0.486, p=0.47, p= 0.595, respectively). Prothrombotic state was found in 33% of our patients and all had increased homocysteine levels. The most common localization of thrombosis was transverse sinus with 50% involvement. Conclusion: This study presented clinical, MRI and laboratory findings of children with CVST and showed no difference in PC, MPV, PDW and MPV/plt ratio between patients and controls. Platelet indices may not be used to support the diagnosis of CVST in children. [ABSTRACT FROM AUTHOR]

Abstract Objectives Management of otogenic cerebral venous thrombosis (OCVT) is controversial. Despite the modern antibiotic era OCVT still represents a potential life-threatening condition. This study aims to report the clinical presentation and management in a series of children with OCTV. The coexisting intracranial complications (ICC), the extent of the surgical treatment and the role of hypocoagulation were the analysed outcomes. Material and Methods Retrospective chart review of patients aged less than 16 years and consecutively treated for OCVT at a tertiary university hospital between January 2007 and March 2015. Results Sixteen children with ages ranging between 25 months and 16 years (9 girls/7 boys) with OCVT were identified. Acute otitis media was the causative factor in the majority of cases (n = 13). The remaining cases resulted from chronic otitis media with cholesteatoma (COMC). Eleven patients were under antibiotic therapy prior to admission. Other ICC were simultaneously present: intracranial abscess (n = 6); otitic hydrocephalus (n = 3); and meningitis (n = 1). Thrombus extension correlated with the presence of additional ICC (p = 0.035). Treatment in all cases comprised of broad-spectrum antibiotics, mastoidectomy, and long-range hypocoagulation with warfarin. Transtympanic ventilation tubes were inserted in all cases but one with COMC. Perioperative sigmoid sinus exposure was performed in seven patients, with drainage of perisinus empyema in three cases. Five children underwent simultaneous craniotomy for intracranial abscess drainage. Follow-up imaging performed in 12 cases revealed partial or complete recanalization in three and seven cases, respectively. After a mean hypocoagulation duration of nine months, no hemorrhagic or major neurologic complications were observed. Conclusions The clinical course of OCVT can be masked by previous antibiotic therapy. As such, a high suspicion index is needed for diagnosis. Simultaneous ICC appears to be more frequently found if an extensive thrombosis was present. The high recanalization rate in this series with low morbidity and no mortality can be obtained with a timely combination of antibiotics, mastoidectomy with transtympanic tube insertion and hypocoagulation. However, the decision to start hypocoagulation and its duration should be undertaken on an individual basis owing the possible adverse effects. Prospective and case-control studies are still needed to better clarify the role of the hypocoagulation treatment in OCVT. [ABSTRACT FROM AUTHOR]

Arterial thrombosis is increasingly recognized in children and is mostly related to the presence of an arterial catheter or an ischemic stroke. Treatment of children with arterial thrombosis varies widely and consists on the administration of the common available anticoagulant und antiplatelet drugs. No evidence-based guidelines are available so far to prefer one treatment approach to another. Data in adults indicate that understanding the pathomechanism and composition of arterial thrombosis is crucial for choosing the most efficient and safe antithrombotic drug. This review will briefly summarize new insights on the pathomechanism and composition of arterial thrombosis in adults and describe available antithrombotic treatment modalities currently used n children. [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate the correlation between thromboelastography (TEG) and conventional measures of anticoagulation, and to determine optimum values for citrated kaolin TEG R time (TEG RCK) and anti- Xa activity that would minimize both bleeding and thrombotic complications in pediatric and neonatal patients requiring extracorporeal membranous oxygenation (ECMO). A retrospective chart review of patients requiring veno-venous (VV) and venoarterial (VA)ECMOwas performed. Combined medical and cardiac ICU within a single-center, tertiary care, freestanding, children's hospital. Non-pregnant patients <18 years and >2 kilograms requiring VV or VA ECMO from July 2013 through July 2015. Anti-Xa (OR = 0.62, 95% CI 0.53-0.72, p < .001) and TEG RCK (OR51.19, 95% CI 1.07-1.34, p5.003) were the only independent predictors for a significant thrombotic event. Receiver operating characteristic curves and traditional epidemiological data (sensitivity, specificity, PPV, NPV) were used to determine optimal target Anti-Xa and TEG RCK values. No independent predictors for significant bleeding events were identified in this cohort. A anti-Xa activity of .25 IU/mL (sensitivity = 81%, specificity = 67%, PPV = 81%, NPV = 58%) and TEG RCK time of 17.85 minutes (sensitivity = 84%, specificity = 68%, PPV = 82%, NPV = 59%) were established as the optimal thresholds for preventing thrombotic events. Anti-Xa and TEG RCK were independent predictors of thrombosis in this cohort of pediatric and neonatal ECMO patients. Targeting an anti-Xa activity greater than .25 IU/mL and a TEG RCK greater than 17.85 minutes may minimize the risk of thrombosis in pediatric and neonatal ECMO patients. Future investigation should evaluate targets for anti-Xa and TEG RCK, which additionally minimize the risk of significant bleeding in this patient population. [ABSTRACT FROM AUTHOR]

The study aims to analyse the clinical and immunological manifestations of paediatric antiphospholipid syndrome (APS) in patients, based on the 2006 revised classification criteria of definite APS. Fifty-eight paediatric patients with APS were enrolled and analysed retrospectively. A total of 37 female and 21 male patients with a mean age of 14 ± 3 years at disease onset were included. Fourteen (24%) cases were primary APS, and 40 (69%) cases were secondary to systemic lupus erythaematosus (SLE). Anti-nuclear antibody (ANA) positivity and hypocomplementemia were more common in secondary APS than in primary APS. The most common manifestations of thrombosis were deep vein thrombosis of the lower extremities (25 cases, 37%). Non-thrombotic manifestations were mainly immunologic thrombocytopenia, autoimmune haemolytic anaemia, skin lesions, arthritis, pulmonary hypertension, heart valve vegetations and spontaneous abortion. LA, ACL and anti-β2GPI were positive in 42 (95%), 28 (64%) and 34 (77%) cases, respectively. Over half (23 cases, 52%) of the patients were triple-positive for antiphospholipid (aPL) antibodies. Among patients with single-positive LA and anti-β2GPI, the proportion with venous thrombosis was 100% (5 cases) and 0% (0 cases), respectively. The arterial thrombosis proportions were 22% (5 cases), 21% (3 cases) and 14% (1 case) in the triple-, double- and single-aPL-positive groups, respectively (P > 0.05). Fifty-three (91%) cases were followed up for 3 to 140 months, with a median time of 32 months. Seven (13%) cases had recurrences or appearances of thrombosis during follow-up, all of which were double- or triple-aPL positive. APS in the paediatric patients is mostly secondary to SLE. ANA positivity and hypocomplementemia are more common in secondary APS, but there are no differences in the other clinical manifestations between the primary and secondary APS groups. Deep vein thrombosis is the most common thrombotic event. Positive LA may increase the risk of venous thrombosis. Multiple-aPL positivity does not increase the proportion of thrombosis. Long-term anticoagulant or antiplatelet therapy is needed to prevent thrombosis recurrence in double- or triple-positive aPL cases. [ABSTRACT FROM AUTHOR]

Cardiovascular thrombosis is rare in children and usually occurs in the presence of predisposing conditions, such as indwelling vascular catheters, tumors, aneurysms, ventricular dysfunction, or after surgery. Clots can occur in the cardiac chambers, arteries or veins, or inside conduits. Detection of thrombi is feasible with a variety of magnetic resonance imaging (MRI) techniques, including unenhanced methods but also contrast-enhanced MR angiography. In this essay we illustrate the MRI appearance of cardiovascular thrombosis in children and suggest an imaging protocol based on our clinical experience. [ABSTRACT FROM AUTHOR]

The article discusses the British Society for Haematology's (BSH) guidelines on the management of thrombotic and haemostatic issues in paediatric malignancy. Topics discussed include the methodology for the creation of the guidelines, venous thromboembolism (VTE) and bleeding as serious complications of cancer and its treatment, assessing and reducing the risk of VTE, treatment of various types of VTE, management of thrombocytopenia and coagulopathy and therapy for menstrual suppression.

Background Pediatric hospital-acquired venous thromboembolism (HA-VTE) rates have increased dramatically. To achieve generalizable knowledge in the derivation and validation of HA-VTE risk factors and risk prediction models and inform future risk-stratified prevention strategies, multi-institutional studies are needed. Objectives This paper presents an investigator-initiated, multicenter pediatric case-cohort study designed to identify risk factors for HA-VTE to create a HA-VTE risk prediction model. Methods A registry, which houses pertinent variables from HA-VTE subjects and non-HA-VTE controls, was created for the Children's Hospital-Acquired Thrombosis (CHAT) study. Specific variables from the registry associated with HA-VTE risk will be identified using multivariable regression to create a pediatric HA-VTE risk prediction model to be prospectively validated. Results Seven large pediatric institutions have entered over 600 HA-VTE subjects aged 0–21 years of age into the registry. Subjects showed a male predominance (57%), a median age of three years (IQR 0.3–13) and were most likely admitted to an intensive care unit (57%) at VTE diagnosis. Median time to HA-VTE was 10 days after admission. The most prevalent risk factors include central venous catheters (80%), surgery (43%), systemic steroids (31%), congenital heart disease (27%), infection (14%) and cancer (13%). Conclusions CHAT, with its creation of a risk prediction model with prospective validation using the CHAT registry, is a novel study design and will be the first step in identifying safe and effective strategies to decrease HA-VTE in children by helping define the highest risk population for initial, or more aggressive, thromboprophylaxis efforts. [ABSTRACT FROM AUTHOR]

Background/aim: Endothelial dysfunction, tissue damage, inflammation, and microthrombosis are involved in the pathogenesis of pulmonary hypertension (PH), which may be present as a complication of congenital heart diseases. This study aims to identify how indicators of endothelial dysfunction (shear stress), tissue damage (brain natriuretic peptide and troponin T), inflammation (C-reactive protein (CRP)), and microthrombosis (D-dimer and von Willebrand factor) are altered in children with congenital left-to-right shunting. Materials and methods: This is a review of 25 children who developed PH due to congenital left-to-right shunting, 40 children who underwent corrective surgery for congenital left-to-right shunting, and 40 healthy children. Results: Serum brain natriuretic peptide (BNP), CRP, and CA-125 levels were significantly increased and shear stress was significantly decreased in children with PH (P = 0.001, P = 0.044, P = 0.012, and P = 0.011). A BNP level of >225 pg/mL had a sensitivity of 95.3% and specificity of 92.4%, whereas a CRP level of >2.2 IU/L had a sensitivity and specificity of 87.5%, and a CA-125 level of >35 IU/mL had a sensitivity of 92.2% and a specificity of 90.4% for PH. Shear stress of <2.5 dyn/cm² had a sensitivity of 84.8% and specificity of 92.9%. Conclusions: A combination of BNP, CRP, CA-125, and shear stress might be used to predict the development of PH during follow-up of children with congenital left-to-right shunting. [ABSTRACT FROM AUTHOR]

Children maintain balanced hemostasis despite many hemostatic differences in comparison to adults with the incidence of thrombosis and hemorrhage in normal children being diminutive. However, there are cohorts of children demonstrated to be a high-risk for thrombosis, which specifically include children with a ventricular assist device (VAD). Adult studies demonstrate that the addition of a VAD to the circulatory system results in hemostatic activation, which unless modulated by antithrombotic therapy (AT), may result in stroke, pump thrombosis, and possibly death. Similar morbidities occur in children with a VAD and with higher incidences [1–5]; yet few studies exist to guide safe and effective AT [2,6,7]. The effect of developmental hemostasis [8,9] and drug metabolism in the presence of a VAD in infants and children are largely unknown. Developmental differences preclude the use of adult guidelines and may predispose children to morbidity and/or mortality. Studies are urgently required to understand the interface between VADs and developmental differences, especially hemostasis. [ABSTRACT FROM AUTHOR]

Pump thrombosis has best been described by Blitz as ‘a riddle wrapped in a mystery inside an enigma’. This statement underscores the issues with understanding pump thrombosis including the lack of a universal definition, the optimal method for diagnosis, and the ideal strategies for prevention and treatment [1]. Most information currently available comes from adult literature, where there continues to be a lack of randomized trials or systematic reviews. The purpose of this article in not to be an exhaustive review, but rather, to synthesize major insights and developments from the recent body of literature that can help to guide diagnosis, prevention, and management of this vexing complication in the pediatric population. [ABSTRACT FROM AUTHOR]

We report four children from different families with homozygous antithrombin (AT) deficiency type II affecting the heparin binding site (p.Leu131Phe mutation). All children had severe spontaneous venous and/or arterial thromboembolic events shortly after birth. This report intends to raise awareness among clinicians about this rare but severe condition. When thrombosis occurs in an otherwise healthy newborn, a severe congenital thrombophilic disorder should be considered. In homozygous AT deficiency type II, AT activity is typically reduced but may also be in the normal range, posing a diagnostic challenge. Rapid diagnosis is important to initiate appropriate therapy. Standard anticoagulation with heparin may prove ineffective in severe AT deficiency, requiring substitution of AT concentrate and early switch to alternative anticoagulants such as vitamin K antagonists. [ABSTRACT FROM AUTHOR]

Thrombotic complications are increasing at a steady and significant rate in children resulting in the more widespread use of anticoagulation in this population. Anticoagulant drugs in children can be divided into the standard agents (heparin, low molecular weight heparin, and vitamin K antagonists) and alternative agents (argatroban, bivalirudin, and fondaparinux). This review will compare and contrast the standard and alternative anticoagulants and suggest situations in which it may be appropriate to use argatroban, bivalirudin, and fondaparinux. Clearly, the standard anticoagulants all have significant shortcomings including variable pharmacokinetics, issues with therapeutic drug monitoring, frequency of administration, efficacy, and adverse effects. The alternative anticoagulants have properties which overcome these shortcomings and prospective clinical trial data are presented supporting the current and future use of these agents in place of the standard anticoagulants. [ABSTRACT FROM AUTHOR]

Absolute values of reference ranges for coagulation assays in humans vary within the entire lifespan and confirm the concept of developmental hemostasis. It is known that physiologic concentrations of coagulation factors (F) gradually increase over age: they are lower in premature infants as compared to full-term babies, healthy children or adults. Here we demonstrate in a cohort of 1011 blood donors and in a group of 193 healthy pregnant women, that the process of developmental hemostasis proceeds in adults. During the course of pregnancy F and activation markers steadily increase until delivery with a parallel decrease noticed for protein S. From adolescents, young adults to the elderly there is a further increase of F, reaching significance starting between 35 and 50 years of age compared to younger subjects. Covering the entire lifespan FVIII and von-Willebrand-factor showed the lowest values in carriers of blood group “O”. Apart from pregnancy differences related to gender, pill users, smoking habits or the presence of thrombophilic variants were reported. Laboratory test results should be compared to age-related reference intervals when hemostatic defects are suspected to avoid misclassifications as being “healthy”, prone to “bleeding” or vice versa to “thrombosis”. [ABSTRACT FROM AUTHOR]

In this narrative review, the epidemiology, diagnosis, prevention strategies, and management of catheter-related thrombosis are outlined. Central venous catheters have significantly improved the quality of life of patients requiring chemotherapy, parenteral nutrition, and chronic transfusions. Catheter-related thrombosis (CRT) complicates between 1–5% of inserted catheters, with incidence varying between patient population, catheter type, and vein cannulated. Strategies to prevent CRT, including anticoagulation and locking solutions, have largely been ineffective. Using clinical decision tools and D-dimer testing can limit radiographic testing for patients with suspected CRT. Although most patients with CRT are treated with anticoagulation, the most effective type and duration of treatment have not been established for adults or children. Many unanswered questions remain concerning risk stratification, prevention, and management of CRT. National and international collaborative research networks could be harnessed to perform these much needed studies. [ABSTRACT FROM AUTHOR]

Background: Fetal thrombotic vasculopathy is a described placental diagnosis associated with adverse perinatal outcomes. It may also predispose children to somatic thromboembolic events. As far as we know, this is the first case of inferior vena cava thrombosis associated with fetal thrombotic vasculopathy in a completely asymptomatic newborn.Case Presentation: We report the case of an asymptomatic, full-term Turkish male neonate delivered at 39 weeks of gestation diagnosed as having thrombosis of the renal vein and inferior vena cava. Diagnosis was guided only by the presence of edematous umbilical cord with macroscopic signs of clotting and, subsequently, microscopic features of the placenta, suggesting fetal thrombotic vasculopathy.Conclusions: Thrombosis of the renal and inferior vena cava in our healthy, asymptomatic full-term neonate is clearly associated with fetal thrombotic vasculopathy. The diagnosis of thrombosis in this neonate was incidental. This suggests that fetal thrombotic vasculopathy may cause unrecognized neonatal thrombosis. Untreated neonatal thrombosis may later compromise growth and function of the involved organs; therefore, maintaining a high index of suspicion based on thrombotic vasculopathy is paramount. [ABSTRACT FROM AUTHOR]

Acute cerebral infarctions are rare in children, however, they can occur as a complication of a Mycoplasma pneumoniae (MP) infection due to direct invasion, vasculitis, or a hypercoagulable state. We report on the case of a 5-year-old boy who had an extensive stroke in multiple cerebrovascular territories 10 days after the diagnosis of MP infection. Based on the suspicion that the cerebral infarction was associated with a macrolide-resistant MP infection, the patient was treated with levofloxacin, methyl-prednisolone, intravenous immunoglobulin, and enoxaparin. Despite this medical management, cerebral vascular narrowing progressed and a decompressive craniectomy became necessary for the patient's survival. According to laboratory tests, brain magnetic resonance imaging, and clinical manifestations, the cerebral infarction in this case appeared to be due to the combined effects of hypercoagulability and cytokineinduced vascular inflammation. [ABSTRACT FROM AUTHOR]

Thrombosis is the result of an imbalance between two complex systems: hemostasis and fibrinolysis. Although the incidence of thromboembolism is lower in children than in adults, the associated morbidity is clinically relevant. This paper summarizes the main risk factors, important to define effective strategies for primary thromboprophylaxis in children at risk, the diagnostic criteria and the optimal therapeutic approach, which, until now, have mostly been extrapolated from the adult's recommendations. [ABSTRACT FROM AUTHOR]

Introduction: Acute basilar artery occlusion (ABAO) is an infrequent but potentially fatal cause of strokes in both adults and children, and it is usually due to vertebral artery dissection (VAD). VAD has been found to be usually a consequence of traumatic vertebral artery injury. ABAO usually presents with symptoms of acute ischemic stroke (AIS) of the posterior circulation or transient ischemic attack (TIA). It may lead to death or long-term disability if not promptly recanalized. Basilar artery recanalization in children can be achieved safely and with excellent clinical outcome using endovascular thrombectomy with the new generation self-expanding and retrievable stents. Clinical presentation: We report the case of a 23-month old baby that came to the emergency room of our hospital for progressive impairment of consciousness associated with widespread stiffness and plaintive cry, appeared after accidental fall from stroller. An emergency brain CT scan was obtained showing multiple infarction lesions in the brainstem and left cerebellum suggestive of acute stroke in posterior circulation territories. An MR scan with angiography and diffusion-weighted sequences confirmed the multiple infarction lesions and demonstrated poor representation of the flow signal at the V3 segment of the left vertebral artery and absent representation of the flow signal at the distal segment of the basilar artery suggestive of acute thrombotic occlusion. The patient was immediately referred to interventional neuroradiology unit, and digital subtraction angiography showed complete basilar artery occlusion and left vertebral artery dissection at extracranial V2-V3 segment. The patient underwent intra-arterial thrombectomy using stent retrievers and occlusion of the V2-V3 segment of the left vertebral artery. The patient survived and long-term outcome was excellent. Conclusions: To our knowledge, only nine cases of ABAO in children treated with intra-arterial thrombectomy have been previously reported in the literature. In only three cases, the Solitaire stent was applied. Our case is the first case of basilar artery occlusion treated with Solitaire stent, in a child under 24 months. The reports that are available so far indicate that basilar artery recanalization in children can be achieved safely and with excellent clinical outcome using endovascular thrombectomy with the new generation self-expanding and retrievable stents. [ABSTRACT FROM AUTHOR]

Pediatric lower extremity deep vein thrombosis (LE-DVT) can lead to postthrombotic syndrome (PTS) and other adverse events. We investigated the outcomes of LE-DVT in children. Three groups were compared: non-line-related (Non-LR) DVT, LR DVT in neonates (LRneonates), and LR DVT in non-neonates (LRnon-neonates). A total of 339 children were included (Non-LR, n556; LRneonates, n595; and LRnon-neonates, n5188).Wefound a statistically significant difference in the frequency of PTS (P 5 .04; 62.5%, 40.0%, and 46.3% in Non-LR, LRnon-neonates, and LRnon-neonates, respectively), of recurrent LE-DVT (P 5 .001; 10.7% and 2.0% in Non-LR and LRnon-neonates, respectively), and pulmonary embolism (PE) (P < .001; 19.6% and 3.2% in Non-LR and LRnon-neonates, respectively) among groups. There was no difference in DVT resolution (P 5 .41). Multivariable analysis showed that DVTresolution, triggering event, and sex predicted Modified Villalta Scale (MVS; for pediatric PTS) scores >1; there wasan interaction between DVT triggering event and sex. The time to reach an MVS >1 was significantly different when comparing groups (log-rank test, P < .001). Moreover, we found a significant difference in baseline MVS scores among groups, but the difference did not appear to changeover time. In conclusion, LRLE-DVT had more benignoutcomes than Non-LR DVT. Sex, DVT triggering event, and DVT resolution predicted LE-PTS in our cohort. [ABSTRACT FROM AUTHOR]

The incidence of venous thromboembolism (VTE) in children is increasing. Hospitalized infants and adolescents are at highest risk, and most individuals who have VTE have multiple thrombotic risk factors. The presence of a central venous catheter (CVC) is the most frequent risk factor for childhood thrombosis. Childhood VTE has significant consequences in relation to the thrombotic event and the anticoagulant therapy used for its treatment. Identification of the most prevalent risk factors for VTE, particularly among adolescents, has moved the focus toward prevention of thrombosis. Risk assessment models have been developed to identify individuals who are at higher risk with a view to employing preventative strategies such as mechanical and chemical thromboprophylaxis (TP). There is currently little evidence to support the efficacy of such strategies for preventing either CVC-associated thrombosis or thrombosis at other sites. In addition, there are concerns about adverse consequences of mechanical and chemical TP in a population where the overall incidence of VTE remains low. [ABSTRACT FROM AUTHOR]

Thromboembolic complications (TECs) are clinically important sequelae of nephrotic syndrome (NS). The incidence of TECs in children is approximately 2%-5%. The veins are the most commonly affected sites, particularly the deep veins in the legs, the inferior vena cava, the superior vena cava, and the renal veins. Arterial thrombosis, which is less common, typically occurs in the cerebral, pulmonary, and femoral arteries, and is associated with the use of steroids and diuretics. Popliteal artery thrombosis in children has been described in cases of traumatic dissection, osteochondroma, Mycoplasma pneumoniae infection, and fibromuscular dysplasia. We report of a 33-month-old girl with bilateral iliac and popliteal arterial thrombosis associated with steroid-resistant NS due to focal segmental glomerulosclerosis. Her treatment involved thrombectomy and intravenous heparinization, followed by oral warfarin for 8 months. Herein, we report a rare case of spontaneous iliac and popliteal arterial thrombosis in a young child with NS. [ABSTRACT FROM AUTHOR]

Purpose: Thrombosis in children is a multifactorial disorder associated with both genetic and acquired factors. Idiopathic thrombosis is a rare condition. This study aimed to examine the etiology and risk factors of thrombosis in pediatric patients followed at Baskent University Adana Teaching and Research Center, a reference hospital in the southern part of Turkey. Material and Methods: This study included a sample of 49 pediatric patients who were retrospectively evaluated. The patient records were examined retrospectively in terms of age at diagnosis with thrombosis, gender, family history of thrombosis, localization of thrombosis, underlying primary disease and presence of catheter, as well as indicators of genetic risk factors. Results: The number of children presenting to our clinic during the study period was 10358. The incidence of thrombosis was calculated as 49 cases in 10358 children. The median age of the patients was 5.1 years (ranging from 0 to 17.2 years), and there were 32 (65.3%) males. In the analysis of the genetic factors causing susceptibility to primary thrombosis, only a portion of the patients were studied for genetic mutations. Among these, 5 patients showed factor V Leiden mutation, 13 patients MTHFR 1298C mutation, and 18 patients MTHFR 677CT mutation. Seven patients were found have a combination of multiple mutations. When we investigated any possible correlation between high lipoprotein (a) levels and the distribution of mutations, we found that 7 patients with mutations had normal levels of high lipoprotein (a), while other 10 patients with mutations were found to have elevated levels of lipoprotein (a). Conclusion: We conclude and strongly emphasize that lipoprotein (a) elevation is one of the important genetic risk factors, which might prove a major risk indicator, as valuable as other mutation screening tests performed by molecular genetics. [ABSTRACT FROM AUTHOR]

Neonatal renal vein thrombosis (NRVT) is a rare thromboembolic complication in the neonatal period, and sequelae from renal dysfunction can cause significant morbidity. The authors retrospectively reviewed 10 patients with NRVT treated at their institution. The majority of the cohort were male (n= 9), preterm (n= 6), and had unilateral NRVT (n= 6). Six patients received thrombolysis and/or anticoagulation, and 4 patients received supportive care only. Two of the 6 patients treated with anticoagulation who had bilateral NRVT and anuria received thrombolysis with low-dose tissue plasminogen activator. Thrombolysis was not associated with any major adverse events, and both patients had marked improvement of renal function. Eight patients subsequently developed renal atrophy (3 received anticoagulation, 2 received thrombolysis with anticoagulation, and 3 received supportive care). Anticoagulation/thrombolysis did not appear to prevent renal atrophy. The role of thrombolysis needs to be further studied and considered in the setting of bilateral NRVT and acute renal failure. [ABSTRACT FROM AUTHOR]

The article discusses a study on cerebral sinovenous thrombosis in children and young adults with acute lymphoblastic leukaemia, in Great Britain. It mentions identification of screening adverse event reports for central nervous system (CNS) thrombosis and grade serious adverse events in the coagulation and thrombosis category. it also highlights temporal relationship of CSVT to L-asparaginase administration during ALL therapy.

The cost of childhood stroke receives little notice. The authors examined potential drivers of cost and outcome to test whether (1) neonatal strokes cost less than childhood strokes, (2) associated diseases influence cost, (3) arterial ischemic stroke is more costly than sinovenous thrombosis, and (4) cost correlates with outcome. The authors reviewed records of 111 children who sustained arterial ischemic stroke or sinovenous thrombosis between 2005 and 2010 to identify costs for the following year. They assessed outcomes in 46 with the Recovery and Recurrence Questionnaire and the Pediatric Quality of Life Inventory. Neonatal strokes cost less than childhood stroke. Strokes associated with congenital heart disease or vasculopathy cost the most, while perinatal or idiopathic strokes cost the least. Higher costs are correlated with worse impairment and poorer quality of life. Stroke etiology significantly influences the cost of pediatric stroke. Future cost–benefit studies must consider etiology when estimating the incremental costs associated with stroke. [ABSTRACT FROM AUTHOR]

Objective Arterial thrombosis is one of the most reported complications of cardiac catheterisation (CC) in children. The aim of the study was to evaluate the incidence and predictors of arterial thrombosis in children with cardiac diseases (CDs). Methods During 12 consecutive months, all children aged 0-19 years undergoing CC of the femoral arteries were included in this observational study. After CC, clinical evaluation of impaired limb perfusion was performed according to local guidelines. Doppler ultrasonography was performed when decreased limb perfusion was suspected. Results 123 children (30% aged <12 months, 70% aged >12 months) underwent CC. Arterial thrombosis occurred in 14 of the 123 children (11.4%). Twelve cases (12/14=86%) of arterial thrombosis occurred in infants aged <12 months and 2 (2/14=14%) in older children. Overall younger age (p<0.01, OR (95% CI) 0.49 (0.28 to 0.86)) and low body weight (p<0.004, OR (95% CI) 0.78 (0.65 to 0.92)) were significantly associated with an increased risk of arterial thrombosis. Cyanotic CD (p=0.07, OR (95% CI) 2.87 (0.90 to 9.15)) showed a trend towards increased thrombotic risk. Conclusions Arterial thrombosis is a common complication of CC in infants. Diagnosis of CC-related arterial thrombosis remains a challenge. Well-defined clinical monitoring protocols may be valuable methods for timely detection and treatment of arterial thrombosis. [ABSTRACT FROM AUTHOR]

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is an uncommon but potentially life threatening disease in children. Pulmonary hemorrhage (PH) is a well recognized but lethal complication. The incidence of venous thromboembolism (VTE) is higher in patients with AAV, especially in those with active disease. However, the simultaneous occurrence of both PH and VTE has rarely been reported. Herein, we describe a 14-year-old female with AAV who developed concomitant deep vein thrombosis (DVT) and PH within 3 days after hospitalization. She was successfully treated with timely plasmapheresis and methylprednisolone pulse therapy. VTE did not occur during discontinuation of anticoagulant. On reviewing the English literature, 5 AAV patients with coexisting VTE and PH have been reported. When faced with PH, whether or not to keep anti-coagulation treatment is a dilemma. Some of the patients kept receiving anti-coagulation treatment, whereas others undergoing inferior vena cava filter implantation. Glucocorticoids and cyclophosphamide or other immunosuppressant agents were prescribed in all patients. All of the cases survived after treatment for concurrent VTE and PH, and received short- or long-term anticoagulation treatment after discharge. To the best of our knowledge, this is the first report of a pediatric patient with AAV presenting with coexistent VTE and PH. VTE should be considered to be a sign of disease flare-up, and early plasmapheresis with immunosuppressant therapy can rescue this fatal complication. [ABSTRACT FROM AUTHOR]

Background Total thrombus formation velocity calculated using amplitude parameters obtained at different times could be used to estimate the amplification and the propagation phases observed during coagulation processes, and therefore might be useful to predict postoperative hemostatic products administration in pediatric patients. Methods We retrospectively analyzed data from 49 children <3 months of age who underwent cardiac surgery. Children ≤1 month of age routinely received fresh frozen plasma during bypass while children >1 month of age did not. The EXTEM parameters were used to calculate velocity curves using amplitudes obtained at different times, the area under the curve called total thrombus formation and the maximum rate of thrombus formation. These parameters were compared between children who received fresh frozen plasma and those who did not. Receiver operating characteristics curves were used to define variables that could be used to predict postoperative fresh frozen plasma transfusion. Results Total thrombus formation and maximum rate of thrombus formation significantly increased in children who received fresh frozen plasma compared to those who did not. Both total thrombus formation and maximum rate of thrombus formation have a better specificity to predict postoperative fresh frozen plasma transfusion compared to clotting time or maximal clot firmness. Conclusion Based on this descriptive study, dynamic ROTEM® parameters of total thrombus formation could be used to estimate the amplification and the propagation phases of coagulation in children. These parameters might be used in further well-designed study to predict the need for hemostatic products in children undergoing cardiac surgery with cardiopulmonary bypass. [ABSTRACT FROM AUTHOR]

Background: Permanent arteriovenous (AV) access is the preferred access for dialysis delivery in children and adolescents requiring chronic hemodialysis (HD). Ultrasound dilution (UD) monitoring of AV access flow is widely used in adult HD units for the early detection of stenosis but experience in pediatrics is limited. Methods: We monitored all maintenance HD patients with AV access using a noninvasive screening algorithm based on UD access flow. We assessed the effectiveness of this algorithm by comparing it to fistulagrams and its impact on AV access-related morbidity. Results: AV access thrombosis rates fell from 13.5 per 100 patient-months on HD during the baseline period to 3.5 per 100 patient-months on HD during the screening period (p < 0.04). The mean blood flow rate by UD measurement was lower in AV accesses that went on to thrombose compared to those without thrombosis (1,203 ml/min/1.73 m2 vs. 1,683 ml/min/1.73 m2, p < 0.001). When compared to fistulagrams, the screening algorithm was 94% sensitive and 77% specific in detecting hemodynamically significant stenosis, with positive and negative predictive values of 83 and 91% respectively. Conclusions: A noninvasive UD screening algorithm of AV access flow is very sensitive in detecting hemodynamically significant stenosis and can decrease AV access thrombosis rates. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Two detailed reviews of the management of neonatal thrombosis were published in 2012; one was an up-dated version of guidance first issued in 2004 and the other was a comprehensive review. Both of these publications gave very similar advice regarding the practical aspects of the indications, dosage and management of antithrombotic therapy. The authors stated that the evidence supporting most of their recommendations for anti-thrombotic therapy in neonates remained weak and so the therapy for a neonate with a thrombosis has to be based on an individualized assessment of estimated risk versus potential benefit. The aim of this present review is to give the treating physician an outline of the unique physiology of neonatal coagulation and how this affects the monitoring, dosing and even the choice of therapeutic strategy for the management of thrombosis in the neonate. [ABSTRACT FROM AUTHOR]

Background: The transjugular intrahepatic portosystemic shunt (TIPS) is effective for treating complications of portal hypertension in cirrhotic adults but the experience in children is limited. Objective: To retrospectively review the safety and efficacy of expanded polytetrafluoroethylene (ePTFE)-covered TIPS in children with acute or recurrent gastrointestinal bleeding. Materials and methods: We reviewed the medical records of children who received implants of 10-mm-diameter PTFE-covered endoprostheses for acute or recurring upper gastrointestinal bleeding caused by medically or endoscopically uncontrollable varices. The recurrence of upper gastrointestinal bleeding, associated complications and permeability were assessed with Doppler sonography sequentially or up to transplantation. Results: In all children ( n = 12; mean age 9 years; mean weight 30 kg) a single endoprosthesis was implanted with no associated mortality. The mean initial transhepatic gradient was 15 mmHg (range 3-21 mmHg), dropping to 7 mmHg (range 1-12 mmHg) after TIPS. Immediate complications were mild encephalopathy ( n = 1) and acute occlusion of the TIPS ( n = 1). Stenosis of the TIPS was observed in two children, at 9 months and 54 months follow-up, and thrombosis was observed in two children, at 7 months and 12 months follow-up. All four stenoses/occlusions were resolved with coaxial endoprostheses. Conclusion: The safety profile and efficacy of expanded polytetrafluoroethylene (ePTFE)-covered TIPS were satisfactory in this small series of children with acute or recurrent gastrointestinal bleeding. [ABSTRACT FROM AUTHOR]

Cases of unexplained intrauterine fetal death (IUFD) can be reduced by full placental examination, with or without autopsy. Determination of the umbilical coiling index (UCI) is considered to be a part of full placental examination. Umbilical hypercoiling (UCI above 0.30 coils/cm) is associated with IUFD. In a large retrospective study, we found an incidence of 18% umbilical hypercoiling in IUFD. We explored the association between umbilical hypercoiling and 2nd- and 3rdtrimester IUFD in 77 cases. There was a significant negative correlation between the UCI and gestational age of IUFD (P < 0.001). More severe cases of hypercoiling were observed in the categories of IUFD at a younger age and with a longer duration. Signs of fetal thrombosis were significantly more present in IUFDs with umbilical hypercoiling. An umbilical cord stricture and hypercoiling seem to be significantly more common in IUFD. The severity of hypercoiling was of no influence on the presence or absence of an umbilical cord stricture. Furthermore, there was no significant difference in signs of cardiac failure between the groups of IUFD with and without umbilical hypercoiling. Our findings may be explained by the theory that hypercoiling leads to a disturbed fetal-placental circulation. Therefore, determination of the UCI should be part of the routine placental examination of cases of IUFD. [ABSTRACT FROM AUTHOR]

The article discusses a study conducted to assess the effect of central venous catheters (CVCs) on catheter-related blood-stream infection (CRBSI) and thrombosis in children. Topics include the analysis of heparin bonded CVCs, using randomized controlled trials (RCTs) to diagnose CRBSI, and inefficiency of CVCs in preventing thrombosis.

Transesophageal echocardiography (TEE) is used in atrial flutter or fibrillation (AFF) before electric cardioversion to detect intracardiac thrombi. Previous studies have described the use of TEE to diagnose intracardiac thrombi in the left atrium and left atrial appendage, which has an incidence of 8 % among patients without congenital heart disease (CHD). In their practice the authors have noted a significant incidence of intracardiac thrombi in other structures of patients with CHD and AFF. This study aimed to determine the incidence and location of intracardiac thrombi using TEE in patients with CHD requiring electric cardioversion of AFF and to compare the use of TEE and transthoracic echo (TTE) to detect intracardiac thrombus in this population. A retrospective chart review of TEE and TTE findings for all patients with CHD who had electric cardioversion of AFF at our institution from 2005 to 2013 was conducted. The diagnosis, presence, and location of intracardiac thrombus were determined. The TEE and TTE results were compared. The study identified 27 patients with CHD who met the study entry criteria at our institution between 2005 and 2013. Seven of these patients had a single ventricle with Fontan palliation. All the patients presented with AFF and had TEE before electric cardioversion. No patients were excluded from the study. The patients ranged in age from 2 to 72 years (median, 21 years) and weighed 17-100 kg (median, 65 kg). The duration of AFF before TEE and attempted cardioversion ranged from 1 day to 3 weeks (median, 3.5 days). Intracardiac thrombus was present in 18 % (5/27) of the patients and in 57 % (4/7) of the Fontan patients with AFF. No embolic events were reported acutely or during a 6-month follow-up period. Among patients with CHD who present with AFF, a particularly high incidence of intracardiac thrombi is present in the Fontan patients that may be difficult to detect by TTE. Thorough TEE examination of the Fontan and related structures is indicated before electric cardioversion of AFF. The incidence of intracardiac thrombus in CHD patients is more than double that reported in non-CHD patients. [ABSTRACT FROM AUTHOR]

Despite its relatively estimated high occurrence, the characterization of pediatric upper extremity deep vein thrombosis (UE-DVT) and of UE postthrombotic syndrome (PTS) is still lacking. We investigated the occurrence, characteristics, and predictors of UE-PTS in a cohort of children with objectively confirmed UE-DVT. Patients were analyzed in 3 groups according to DVT pathogenesis and neonatal status: primary (G1), secondary neonates (G2neonates), and non-neonates (G2non-neoates)- A total of 158 children (23 G1,25 G2neonates, and 110 G2non-neoates were included. The most common triggering factors were effort-related (87%) in G1 and central lines in G2neonates (100%) and in G2neonates (92%). PTS scores ⩾1, as per the Modified Villalta Scale, were identified in 87% of primary patients, 16% of G2non-neoates , and 49% of G2non-neoates - Survival analysis showed that the time to PTS score ⩾1 significantly differed among group (log-rank test P <.0001). A multivariable logistic regression showed that DVT pathogenesis and imaging-determined degree of thrombus resolution at the end of therapy were independent predictors of a PTS score 22. In conclusion, pediatric UE-PTS frequency and severity depend on UE-DVT pathogenesis (primary/secondary) and, within the secondary group, on patient's age. Line-related UE-PTS has a more benign course, particularly in neonates. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Otogenic sigmoid sinus thrombosis is a rare complication of acute otitis media. Treatment remains controversial particularly regarding extent of surgical intervention. The aim of the study was to review the 12-year experience of a major medical center with the treatment of sigmoid sinus thrombosis in children. Methods: Retrospective case series identified by database review in a tertiary university-affiliated pediatric medical center. Twenty-four children aged 7–155 months were treated for sigmoid sinus thrombosis from 2000 through 2011. Results: The transverse sinus was also involved in 10 patients, and the jugular vein, in 4. Acute otitis media with mastoiditis was the causative factor in all cases. Subperiosteal abscess was diagnosed in 21 patients, 11 with epidural involvement. Treatment in all cases consisted of broad-spectrum antibiotics and ventilation tube insertion. Twenty-one children (87.5%) underwent mastoidectomy with removal of bone covering the sigmoid sinus to drain pus and remove granulations from the epidural cavity, without aspiration or sinus drainage. Twenty-two patients received low-molecular-weight heparin for 3–6 months postoperatively. Children infected with Fusobacterium necrophorum had a longer and more severe course with coexisting osteomyelitis. There were no neurologic sequelae or hematologic complications. Follow-up imaging, performed in 15 children, revealed partial or full recanalization in 87%. Conclusions: Relatively conservative surgical intervention appears to yield good results in children with sigmoid sinus thrombosis consequent to acute otitis media. Anticoagulants are safe if correctly administered and may prevent extension of the thrombus. [Copyright &y& Elsevier]

Background: Neonatal aortic arch thrombosis is a rare but life threatening condition. A correct diagnosis and an appropriate therapeutic approach are fundamental to prevent death or severe injuries. Case presentation: we report a case of spontaneous aortic arch thrombosis in a term newborn, who presented with suggestive signs of aortic coarctation immediately after birth. Despite the initiation of anticoagulant therapy, a massive increase in size of thrombus with evidence of coronary involvement was noted. Thrombolytic treatment was performed with thrombus resolution. Death occurred after a few days due to widespread brain haemorrhage. Conclusion: To date, no definitive guidelines have been published for the treatment of neonatal aortic arch thrombosis, and only anecdotal reports are available. A multidisciplinary approach is fundamental in order to evaluate the risk:benefit ratio of proposed medical and surgical interventions. Further studies are needed to improve consensus evidence based guidelines and ensure appropriate approaches to this condition. [ABSTRACT FROM AUTHOR]

Aim The aim of the study was to develop and implement a protocol for the prevention and treatment of catheter related intraluminal thrombosis in a paediatric intensive care unit Methods A computerised search was carried out on MEDLINE, through Pub Med, using the medical subject heading 'central venous catheter', 'central venous access device', 'central venous line' associated with 'occlusion', 'obstruction', 'catheter-related thrombosis', 'critically ill patients' and 'thrombolytic therapy'. References of reviewed articles were also searched for relevant titles as well as non-randomised controlled trials and series of cases when no information of higher level of evidence was available. Results With the information gathered, a protocol for the prevention and treatment of catheter related intraluminal thrombosis was elaborated and those recommendations that best suit our environment were included. They were agreed upon by a broad panel of professionals working in the Pediatric Intensive Care Unit and the Pharmacy Department. Conclusions Due to the variety of options available for the pharmacotherapeutic management of intraluminal catheter thrombosis, one measure to improve the quality of the therapy and to diminish the variability in the prescription could be the implementation of a protocol as described in this paper. [ABSTRACT FROM AUTHOR]

Background: Venous thromboembolism has been increasingly recognised as a clinical problem in the paediatric population. Guideline recommendations for antithrombotic therapy in paediatric patients are based mainly on extrapolation from adult clinical trial data, owing to the limited number of clinical trials in paediatric populations. The oral, direct Factor Xa inhibitor rivaroxaban has been approved in adult patients for several thromboembolic disorders, and its well-defined pharmacokinetic and pharmacodynamic characteristics and efficacy and safety profiles in adults warrant further investigation of this agent in the paediatric population. Objective: The objective of this study was to develop and qualify a physiologically based pharmacokinetic (PBPK) model for rivaroxaban doses of 10 and 20 mg in adults and to scale this model to the paediatric population (0-18 years) to inform the dosing regimen for a clinical study of rivaroxaban in paediatric patients. Methods: Experimental data sets from phase I studies supported the development and qualification of an adult PBPK model. This adult PBPK model was then scaled to the paediatric population by including anthropometric and physiological information, age-dependent clearance and age-dependent protein binding. The pharmacokinetic properties of rivaroxaban in virtual populations of children were simulated for two body weight-related dosing regimens equivalent to 10 and 20 mg once daily in adults. The quality of the model was judged by means of a visual predictive check. Subsequently, paediatric simulations of the area under the plasma concentration-time curve (AUC), maximum (peak) plasma drug concentration ( C) and concentration in plasma after 24 h ( C) were compared with the adult reference simulations. Results: Simulations for AUC, C and C throughout the investigated age range largely overlapped with values obtained for the corresponding dose in the adult reference simulation for both body weight-related dosing regimens. However, pharmacokinetic values in infants and preschool children (body weight <40 kg) were lower than the 90 % confidence interval threshold of the adult reference model and, therefore, indicated that doses in these groups may need to be increased to achieve the same plasma levels as in adults. For children with body weight between 40 and 70 kg, simulated plasma pharmacokinetic parameters ( C, C and AUC) overlapped with the values obtained in the corresponding adult reference simulation, indicating that body weight-related exposure was similar between these children and adults. In adolescents of >70 kg body weight, the simulated 90 % prediction interval values of AUC and C were much higher than the 90 % confidence interval of the adult reference population, owing to the weight-based simulation approach, but for these patients rivaroxaban would be administered at adult fixed doses of 10 and 20 mg. Conclusion: The paediatric PBPK model developed here allowed an exploratory analysis of the pharmacokinetics of rivaroxaban in children to inform the dosing regimen for a clinical study in paediatric patients. [ABSTRACT FROM AUTHOR]

The article discusses on the thrombosis' prevention and treatment in pediatric and congenital heart disease. It explores the hemostasis in children with information on initiation of coagulation, amplification, and regulation of thrombin and fibrin. It highlights the agents for its treatment and prevention, such as heparin-induced thrombocytepenia and measures of anticoagulant effect. It also focuses on the special considerations with warfarin therapy in children.

Abstract: Introduction: The recent proliferation of deep vein thrombosis in children has been attributed to the increased use of central venous catheters, specifically tunneled lines and peripherally inserted central catheters. A formal comparison of the incidence rate for deep vein thrombosis between tunneled lines and peripherally inserted central catheters has not been undertaken. Methods: Children <18years of age who were admitted to Children’s Hospital Los Angeles from July, 2005 to July, 2012 were eligible for inclusion. Data were extracted from the hospital discharge database which includes data on all procedures and up to 20 diagnoses per admission. Diagnoses and procedures were identified by International Classification of Disease, Ninth Revision coding. Patients were excluded if they received more than one central line. Data collected included type of central line, deep vein thrombosis event, and underlying medical illnesses classified according to chronic complex conditions. Results: Over the seven year study period there was an overall rate of 73 deep vein thromboses per 10,000 hospital discharges. Of the 6915 eligible subjects, 181 had a deep vein thrombosis for an overall incidence rate of 2.6%. There were 152 thrombi (2.6%) in subjects with peripherally inserted central catheters and 29 thrombi (3.1%) in subjects with tunneled lines [OR=.83 (0.55, 1.29), p=0.38]. Conclusion: Despite the relative ease and simplicity of use of peripherally inserted central catheters leading to a substantial rise in their use, this study demonstrates that such lines pose a substantial risk for venous thrombosis and no difference in incidence was detected between such lines and tunneled lines. [Copyright &y& Elsevier]

The article describes several case reports related to pediatrics. A deep vein thrombosis associated with dengue fever was reported in an 11-year-old boy presented with high grade fever for the past seven days, headache, arthralgia, myalgia, nausea, abdominal pain and right calf pain. Another case involved a four-days-old full term female infant with respiratory distress, lethargy and poor feeding and diagnosed with neonatal aortic thrombosis as a result of congenital homocystinuria.

Objectives -- To investigate the dose of enoxaparin required in neo-nates to achieve target therapeutic ranges of anti factor Xa 48 hours after starting therapy, and compare this dose to recommended guideline dosages for neonates. Methods -- We retrospectively reviewed 19 records of newborns who received enoxaparin at different doses for the treatment of thrombosis and evaluated how many among them reached the target anti-factor Xa level after 48 hours. Results -- Only 1/5 neonates (20%) treated with 150 UI/kg twice a day, but 100% (6/6) of those treated with 175 UI/kg twice a day reached therapeutic levels of anti-factor Xa at 48 hours. Of the 8 neonates treated with lower starting doses none reached the therapeutic range after 48 hours and these required the highest number of dose changes. Conclusions -- Our results reinforce the need to increase in neonates the dosage of enoxaparin suggested in published guidelines, in order to shorten the time-delay in achieving a therapeutic level of anti-factor Xa, and also reducing the number of blood tests necessary for dosing anti-factor Xa. [ABSTRACT FROM AUTHOR]