Effects of an acidic environment on coagulation dynamics
Essentials Acidosis, an outcome of traumatic injury, has been linked to impaired procoagulant efficiency. In vitro model systems were used to assess coagulation dynamics at pH 7.4 and 7.0. Clot formation dynamics are slightly enhanced at pH 7.0 in blood ex vivo. Acidosis induced decreases in antithr...
Saved in:
Published in | Journal of thrombosis and haemostasis Vol. 14; no. 10; pp. 2001 - 2010 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Wiley Subscription Services, Inc
01.10.2016
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Essentials
Acidosis, an outcome of traumatic injury, has been linked to impaired procoagulant efficiency.
In vitro model systems were used to assess coagulation dynamics at pH 7.4 and 7.0.
Clot formation dynamics are slightly enhanced at pH 7.0 in blood ex vivo.
Acidosis induced decreases in antithrombin efficacy offset impairments in procoagulant activity.
Summary
Background
Disruption of hydrogen ion homeostasis is a consequence of traumatic injury often associated with clinical coagulopathy. Mechanisms by which acidification of the blood leads to aberrant coagulation require further elucidation.
Objective
To examine the effects of acidified conditions on coagulation dynamics using in vitro models of increasing complexity.
Methods
Coagulation dynamics were assessed at pH 7.4 and 7.0 as follows: (i) tissue factor (TF)‐initiated coagulation proteome mixtures (±factor [F]XI, ±fibrinogen/FXIII), with reaction progress monitored as thrombin generation or fibrin formation; (ii) enzyme/inhibitor reactions; and (iii) TF‐dependent or independent clot dynamics in contact pathway‐inhibited blood via viscoelastometry.
Results
Rate constants for antithrombin inhibition of FXa and thrombin were reduced by ~ 25–30% at pH 7.0. At pH 7.0 (+FXI), TF‐initiated thrombin generation showed a 20% increase in maximum thrombin levels and diminished thrombin clearance rates. Viscoelastic analyses showed a 25% increase in clot time and a 25% reduction in maximum clot firmness (MCF). A similar MCF reduction was observed at pH 7.0 when fibrinogen/FXIII were reacted with thrombin. In contrast, in contact pathway‐inhibited blood (n = 6) at pH 7.0, MCF values were elevated 6% (95% confidence interval [CI]: 1%–11%) in TF‐initiated blood and 15% (95% CI: 1%– 29%) in the absence of TF. Clot times at pH 7.0 decreased 32% (95% CI: 15%–49%) in TF‐initiated blood and 51% (95% CI: 35%–68%) in the absence of TF.
Conclusions
Despite reported decreased procoagulant catalysis at pH 7.0, clot formation dynamics are slightly enhanced in blood ex vivo and suppression of thrombin generation is not observed. A decrease in antithrombin reactivity is one potential mechanism contributing to these outcomes. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1538-7933 1538-7836 1538-7836 |
DOI: | 10.1111/jth.13418 |