scholarly journals Antithrombin III Supplementation in a Premature Infant: Is There a Target Antithrombin Level?

2021 ◽  
Vol 26 (8) ◽  
pp. 850-856
Author(s):  
Ankit Shukla ◽  
Chi Braunreiter
Keyword(s):  
Molecular Weight ◽  
Premature Infant ◽  
Critically Ill ◽  
Premature Infants ◽  
Low Molecular Weight Heparin ◽  
Inferior Vena ◽  
Antithrombin Iii ◽  
Vena Cava ◽  
Low Molecular Weight ◽  
Optimal Target

The optimal antithrombin (AT) activity for low-molecular-weight heparin efficacy and the benefits of antithrombin III (ATIII) supplementation in premature infants diagnosed with venous thromboembolism are unknown. Currently, there are no neonatal-specific guidelines directing the appropriate target AT activity during supplementation. This case report describes a critically ill premature infant with a progressive, occlusive inferior vena cava thrombus who received supplemental ATIII during enoxaparin treatment. The patient did not achieve therapeutic anti-Xa levels despite increasing enoxaparin dosing to 3 mg/kg every 12 hours. ATIII supplementation sufficient to attain an AT activity of >40%, in combination with an enoxaparin dosing of >2 mg/kg every 12 hours, was needed to achieve therapeutic anti-Xa levels. Future large studies are needed to determine if there is an optimal target AT activity for critically ill premature infants.

scholarly journals Efficacy, Safety, and Timing of Anticoagulant Thromboprophylaxis for the Prevention of Venous Thromboembolism in Patients With Acute Spinal Cord Injury: A Systematic Review

2017 ◽  
Vol 7 (3_suppl) ◽  
pp. 138S-150S ◽  
Author(s):  
Paul M. Arnold ◽  
James S. Harrop ◽  
Geno Merli ◽  
Lindsay G. Tetreault ◽  
Brian K. Kwon ◽  
...  
Keyword(s):  
Systematic Review ◽  
Molecular Weight ◽  
Lower Risk ◽  
Low Molecular Weight Heparin ◽  
Inferior Vena Cava Filter ◽  
Inferior Vena ◽  
Vena Cava ◽  
Low Molecular Weight ◽  
Mechanical Prophylaxis ◽  
Cord Injury

Study Design: Systematic review. Objectives: The objective of this study was to answer 5 key questions: What is the comparative effectiveness and safety of (1a) anticoagulant thromboprophylaxis compared to no prophylaxis, placebo, or another anticoagulant strategy for preventing deep vein thrombosis (DVT) and pulmonary embolism (PE) after acute spinal cord injury (SCI)? (1b) Mechanical prophylaxis strategies alone or in combination with other strategies for preventing DVT and PE after acute SCI? (1c) Prophylactic inferior vena cava filter insertion alone or in combination with other strategies for preventing DVT and PE after acute SCI? (2) What is the optimal timing to initiate and/or discontinue anticoagulant, mechanical, and/or prophylactic inferior vena cava filter following acute SCI? (3) What is the cost-effectiveness of these treatment options? Methods: A systematic literature search was conducted to identify studies published through February 28, 2015. We sought randomized controlled trials evaluating efficacy and safety of antithrombotic strategies. Strength of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Results: Nine studies satisfied inclusion criteria. We found a trend toward lower risk of DVT in patients treated with enoxaparin. There were no significant differences in rates of DVT, PE, bleeding, and mortality between patients treated with different types of low-molecular-weight heparin or between low-molecular-weight heparin and unfractionated heparin. Combined anticoagulant and mechanical prophylaxis initiated within 72 hours of SCI resulted in lower risk of DVT than treatment commenced after 72 hours of injury. Conclusion: Prophylactic treatments can be used to lower the risk of venous thromboembolic events in patients with acute SCI, without significant increase in risk of bleeding and mortality and should be initiated within 72 hours.

scholarly journals Is Low Molecular Weight Heparin the Treatment of choice for Neonatal Thrombosis?

2020 ◽  
Vol 5 (2) ◽  
Keyword(s):  
Risk Factors ◽  
Molecular Weight ◽  
Caesarean Section ◽  
Low Molecular Weight Heparin ◽  
Inferior Vena ◽  
Left Renal Vein ◽  
Vena Cava ◽  
Emergency Caesarean Section ◽  
Low Molecular Weight ◽  
Preterm Baby

A borderline preterm baby is born with an emergency caesarean section. The baby is found to have an unprovoked occlusive thrombosis in the left renal vein and inferior vena cava. There are no obvious risk factors for thrombosis. The baby is commenced on un-fractionated heparin (UFH) followed by a prolonged course of low molecular weight heparin (LMWH) based on the guidelines adopted from adult evidence. You wonder if this is reasonable to treat neonates as per adult guidelines given the great differences between adult and neonatal clotting parameters.

Covalent Complexes Between Low Molecular Weight Heparin Fragments and Antithrombin III – Inhibition Kinetics and Turnover Parameters

1983 ◽  
Vol 49 (02) ◽  
pp. 109-115 ◽  
Author(s):  
M Hoylaerts ◽  
E Holmer ◽  
M de Mol ◽  
D Collen
Keyword(s):  
Molecular Weight ◽  
Half Life ◽  
Low Molecular Weight Heparin ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Life Time ◽  
Low Molecular Weight ◽  
High Affinity ◽  
Plasma Half Life ◽  
Covalent Complex

SummaryTwo high affinity heparin fragments (A/r 4,300 and M, 3,200) were covalently coupled to antithrombin III (J. Biol. Chem. 1982; 257: 3401-3408) with an apparent 1:1 stoichiometry and a 30-35% yield.The purified covalent complexes inhibited factor Xa with second order rate constants very similar to those obtained for antithrombin III saturated with these heparin fragments and to that obtained for the covalent complex between antithrombin III and native high affinity heparin.The disappearance rates from plasma in rabbits of both low molecular weight heparin fragments and their complexes could adequately be represented by two-compartment mammillary models. The plasma half-life (t'/j) of both low Afr-heparin fragments was approximately 2.4 hr. Covalent coupling of the fragments to antithrombin III increased this half-life about 3.5 fold (t1/2 ≃ 7.7 hr), approaching that of free antithrombin III (t1/2 ≃ 11 ± 0.4 hr) and resulting in a 30fold longer life time of factor Xa inhibitory activity in plasma as compared to that of free intact heparin (t1/2 ≃ 0.25 ± 0.04 hr).

NEUTRALIZING EFFECT OF PLATELET FACTOR 4 OR HISTIGINE-RICH GLYCOPROTEIN AGAINST LOW MOLECULAR WEIGHT HEPARIN AND UNFRACTIONATED HEPARIN

1987 ◽  
Author(s):  
K Takahashi ◽  
M Niwa ◽  
N Sakuragawa
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Antithrombin Iii ◽  
Platelet Factor 4 ◽  
Low Molecular Weight ◽  
Bleeding Tendency ◽  
Human Origin ◽  
Platelet Factor ◽  
At Iii ◽  
Antifactor Xa

Purpose: Low molecular weight(LMW) heparin shows stronger antifactor Xa(F-Xa) and weaker anti-thrombin(TH) activities compared with unfractionated(UF) heparin, and shows less bleeding tendency in the cases of clinical use. Platelet factor 4(Pf-4) and histidine-rich glycoprotein(HRG) neutralize heparin. We investigated on the heparin neutralizing effects of them to both kinds of heparinMaterials and methods: LMW heparin(Kabi and Pharmuka) and UF heparin(Novo) were used. Antithrombin III(AT-III), HRG(human origin ) and pf-4( bovine origin ) were purified by our methodsTH(Green-Cross) and F-Xa(Sigma) were used. Reaction mixtures for anti-TH or anti-F-Xa were as follows: 1 vol of AT-III( 0.1 U/ml)+ 1 vol of heparin( 10 ug/ml)+l vol of pf-4 or HRG(varied)→incubated for 5 min→+l vol of TH(5 U/ml) or F-Xa( 7 nKat/ml)→incubated for 5 min→ + S-2238 or S-2222→ recorded at 405 nm.Results: (1) Pf-4 showed the equivalent anti-TH effect on both kinds of heparin, and 3 ug of pf-4 neutralized 1 ug of heparinOn F-Xa neutralizing effect, 13 ug of pf-4 neutralized 1 ug of UF heparin, but could not neutralize LMW heparin. (2) HRG showed the same results on anti-TH effect of both kinds of heparin, but could not neutralize the anti-F-Xa effect of LMW heparin on the same amount of HRG which neutralized that of UF heparin. Conclusion: Anti-F-Xa effect of. LMW heparin could not be easily neutralized by pf-4 or HRG compared with that of UF heparin.

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