A low volume specimen container suitable for monitoring the aPTT of heparinized patients

Ray, Michael; Carroll, P. A.; Just, Sarah; Hawson, G. A. T.

doi:10.1097/00001721-199304050-00020

Cited by 4 publications

(4 citation statements)

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“…Alternatively, the sample can be collected into citrate‐theophylline‐adenosine‐ dipyridamole (CTAD), which protects the sample from loss of heparin via platelet factor 4 (PF4)‐mediated neutralization (Contant et al , ; van den Besselaar et al , ). Heparin is lost more rapidly in citrate tubes that contain a large air space (after addition of blood) as a consequence of accelerated platelet activation and release of PF4, an effect that is abolished if CTAD is used (Ray et al , ).…”

Section: Unfractionated Heparinmentioning

confidence: 99%

Measurement of non‐Coumarin anticoagulants and their effects on tests of Haemostasis: Guidance from the British Committee for Standards in Haematology

et al. 2014

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The guideline group was selected to include UK-based medical, scientific and laboratory representatives. Publications known to the writing group were supplemented with additional papers identified by searching MEDLINE/Pubmed using the keywords direct thrombin inhibitors (DTI), direct Xa inhibitors, apixaban, argatroban, bivalirudin, dabigatran, fondaparinux, rivaroxaban, in combination with measurement, monitoring, coagulation assays, haemostasis assays and laboratory tests.The writing group produced the draft guideline, which was subsequently revised by consensus by members of the Haemostasis and Thrombosis Task Force of the British Committee for Standards in Haematology (BCSH). The BCSH GRADE system was not applied to this guideline as it is inappropriate for laboratory studies. The guideline was then reviewed by a sounding board of c. 50 UK haematologists, the BCSH and British Society for Haematology (BSH) Committee and comments were incorporated where appropriate.The objective of this guideline is to provide healthcare professionals with clear guidance on the clinically important issues regarding the laboratory assessment of currently used non-coumarin anticoagulants and their impact on laboratory tests of haemostasis.A short summary of the effects of rivaroxaban and dabigatran on routine coagulation screens and assessment of anticoagulation intensity on behalf of the BCSH and international recommendations related to measurement of oral direct inhibitors (Baglin et al, 2013) have recently been published.The sections on heparin and low molecular weight heparin (LMWH) represent an update of the previously issued guidance (Baglin et al, 2006).

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Section: Unfractionated Heparinmentioning

confidence: 99%

Measurement of non‐Coumarin anticoagulants and their effects on tests of Haemostasis: Guidance from the British Committee for Standards in Haematology

et al. 2014

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“…Heparin is lost more rapidly in citrate tubes that contain a large air space (after addition of blood) due to accelerated platelet activation and release of PF4. This effect is suppressed if CTAD is used [ 32 ].…”

Section: Samples Acquisition Processing and Storagementioning

confidence: 99%

Measurement of non-VKA oral anticoagulants versus classic ones: the appropriate use of hemostasis assays

et al. 2014

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Traditional anticoagulant agents such as vitamin K antagonists (VKAs), unfractionated heparin (UFH), low molecular weight heparins (LMWHs) and fondaparinux have been widely used in the prevention and treatment of thromboembolic diseases. However, these agents are associated with limitations, such as the need for regular coagulation monitoring (VKAs and UFH) or a parenteral route of administration (UFH, LMWHs and fondaparinux).Several non-VKA oral anticoagulants (NOACs) are now widely used in the prevention and treatment of thromboembolic diseases and in stroke prevention in non-valvular atrial fibrillation. Unlike VKAs, NOACs exhibit predictable pharmacokinetics and pharmacodynamics. They are therefore usually given at fixed doses without routine coagulation monitoring. However, in certain patient populations or special clinical circumstances, measurement of drug exposure may be useful, such as in suspected overdose, in patients experiencing a hemorrhagic or thromboembolic event during the treatment’s period, in those with acute renal failure, in patients who require urgent surgery or in case of an invasive procedure. This article aims at providing guidance on laboratory testing of classic anticoagulants and NOACs.Electronic supplementary materialThe online version of this article (doi:10.1186/1477-9560-12-24) contains supplementary material, which is available to authorized users.

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“…Recombinant thrombin inhibitors such as hirudin may be better anticoagulants for functional cellular assays, but its high cost mitigates against routine use (7). In addition, Citrate-Theophylline-Adenosine-Dipyridamole (CTAD) has been reported to decrease platelet activation as indicated by lowering the plasma concentrations of platelet factor 4 and to prevent platelet activation in vitro during the storage of tubes at room temperature before analysis (8).…”

Section: Introductionmentioning

confidence: 99%

Assessment of platelet activation in several different anticoagulants by the Advia 120 Hematology System, fluorescence flow cytometry, and electron microscopy

Ahnadi¹,

Chapman²,

Lépine³

et al. 2003

Thromb Haemost

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In vivo platelet activation results are often confounded by activation induced in vitro during the preparative procedures. We measured ex vivo (basal) and in vitro (thrombin-induced) platelet activation in sodium citrate, ethylenediaminetetraacetic acid (EDTA), and Citrate Theophylline Dipyridamole Adenosine (CTAD) whole blood specimens. Determinations were made by measurements of platelet density (mean platelet component: MPC concentration) on the Advia 120 Hematology System. The MPC has been previously shown to correlate with a fluorescence flow cytometric method, also determined in this study, using the surface expression of CD62P. Moreover, platelet shape and structure changes in EDTA and CTAD anticoagulated whole blood specimens were characterized by transmission electron microscopy (TEM). Observations made using the Advia 120 Hematology System platelet density parameter, MPC, in the absence of thrombin were 25.7 +/- 0.9 g/dl, 27.9 +/- 0.9 g/dl and 24.8 +/- 1.2 g/dl in sodium citrate, EDTA and CTAD whole blood specimens, respectively. Addition of thrombin induced a significant change in platelet MPC for sodium citrate (21.9 +/- 1.9 g/dl; p<0.0001) and EDTA (23.2 +/- 0.9 g/dl; p<0.0001) whole blood specimens. In contrast, thrombin had no effect on MPC measured in whole blood taken into CTAD tubes. In vitro fluorescence flow cytometric platelet activation experiments measuring the percentage of platelets expressing anti-CD62P showed increase in sodium citrate specimens from 9.2 +/- 7.0 to 55.5 +/- 23.1 % (p<0.0001) and in EDTA specimens from 1.9 +/- 1.7 to 64.6 +/- 12.4 % (p<0.0001) after addition of thrombin. However, in blood taken into CTAD tubes, there was no significant change. Studies on platelets isolated from whole blood in CTAD showed activation by thrombin indicating that platelets in CTAD, while protected in its presence remained functional upon its removal. When observed by TEM over time, platelets in EDTA appear more activated and contain fewer granules than platelets in CTAD. We conclude that CTAD demonstrates in vitro platelet activation inhibition and may be useful in stabilizing ex vivo platelet activation. The novel platelet activation parameter, MPC, measured by an automated routine hematology system, using customized proprietary software, may be used in conjunction with CTAD, a stabilizing anticoagulant, to measure the ex vivo platelet activation state in whole blood specimens. TEM studies verify shape modifications and simultaneous retention of intracellular granules at early post-venipuncture time periods in CTAD specimens.

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A low volume specimen container suitable for monitoring the aPTT of heparinized patients

Cited by 4 publications

References 0 publications

Measurement of non‐Coumarin anticoagulants and their effects on tests of Haemostasis: Guidance from the British Committee for Standards in Haematology

Measurement of non‐Coumarin anticoagulants and their effects on tests of Haemostasis: Guidance from the British Committee for Standards in Haematology

Measurement of non-VKA oral anticoagulants versus classic ones: the appropriate use of hemostasis assays

Assessment of platelet activation in several different anticoagulants by the Advia 120 Hematology System, fluorescence flow cytometry, and electron microscopy

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