Articles: partial-thromboplastin-time.
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Intensive care medicine · Feb 2003
Comparative StudyThe use of the activated clotting time for monitoring heparin therapy in critically ill patients.
To determine the correlation between activated clotting time (ACT) and activated partial thromboplastin time (aPTT) in patients receiving intravenous unfractionated heparin therapy, and the accuracy of the ACT in predicting the level of anticoagulation. ⋯ The correlation between the aPTT and the ACT in this ICU setting is poor; ACT cannot differentiate between low and therapeutic levels of anticoagulation. The use of the ACT for monitoring low to moderate doses of heparin in ICU patients cannot be recommended.
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Intensive care medicine · Jan 2003
Early identification of sepsis and mortality risks through simple, rapid clot-waveform analysis. Implications of lipoprotein-complexed C reactive protein formation.
To determine if the rapid waveform profile of the activated partial thromboplastin time (aPTT) assay, which detects lipoprotein-complexed C reactive protein (LCCRP) formation, predicts sepsis and mortality in critically ill patients. ⋯ Waveform analysis within the first hour of ITU admission is a single, simple and rapid method of identifying the risks of mortality and sepsis. Its measure of LCCRP formation shows superior prediction over CRP alone and it warrants further assessment as a tool to triage and target prompt, appropriate treatment in the ITU.
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The purpose of this study was to compare results obtained for the prothrombin time (PT) and the activated partial thromboplastin time (APTT) using specimens drawn with and without a discard tube in healthy adults. ⋯ Relative to sampling from a population of healthy adults, drawing a discard tube before a sodium citrate tube for coagulation testing appears to make an insignificant difference. Replication of these results with patients receiving anticoagulant therapy and/or patients with abnormal coagulation results, would offer cost savings by justifying elimination of discard tubes for blood draws for coagulation testing only. Such a change in protocol would also reduce the likelihood of nosocomial blood loss in vulnerable patient populations.
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Anesthesia and analgesia · Dec 2002
Comparative StudyThe detection of changes in heparin activity in the rabbit: a comparison of anti-xa activity, thrombelastography, activated partial thromboplastin time, and activated coagulation time.
Thrombelastography (TEG) has been used to detect both exogenous and endogenous circulating heparin activity in clinical and laboratory settings. Thus, in this study I sought to compare the sensitivity of TEG, activated partial thromboplastin time (aPTT), and activated coagulation time (ACT) values with changes in anti-Xa activity after small-dose heparin administration in rabbits. Conscious rabbits (n = 11) had blood obtained from ear arteries for hematological analyses after the administration of 0, 10, 20, and 30 U/kg of IV heparin. Anti-Xa activities after the administration of 0, 10, 20, and 30 U/kg of heparin were, respectively, 38 +/- 9 mU/mL, 74 +/- 15 mU/mL, 105 +/- 14 mU/mL, and 134 +/- 17 mU/mL; all values were significantly different from each other. TEG variables (R and alpha) significantly (P < 0.05) changed between 0, 10, and 20 U/kg heparin doses, but a difference between 20 and 30 U/kg could not be discerned secondary to loss of a detectable clot. The aPTT was significantly (P < 0.05) different between 0, 20, and 30 U/kg doses. ACT values were significantly different between the 0 U/kg heparin dose and all other doses; however, there were no significant differences between the 10, 20, and 30 U/kg heparin doses. Changes in anti-Xa activity were significantly linearly related to R (r = 0.81, P < 0.0001), alpha (r = -0.85, P < 0.0001), aPTT (r = 0.74, P < 0.0001), and ACT (r = 0.41, P = 0.005). In this model of small-dose heparin administration, TEG variables were more sensitive to changes in heparin activity than aPTT and ACT. ⋯ Changes in thrombelastography (TEG) variables more sensitively reflect changes in circulating heparin activity than activated partial thromboplastin time (aPTT) and activated coagulation time (ACT) after small-dose heparin administration in rabbits. Thus, TEG may be more helpful than aPTT and ACT in the detection of heparin in both laboratory and clinical settings wherein heparin may play a role in coagulopathy.
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J. Thromb. Thrombolysis · Oct 2002
Review Randomized Controlled Trial Clinical TrialThe determinants of activated partial thromboplastin time, relation of activated partial thromboplastin time to clinical outcomes, and optimal dosing regimens for heparin treated patients with acute coronary syndromes: a review of GUSTO-IIb.
Unfractionated heparin remains widely utilized in the treatment of acute coronary syndromes (ACS). However, limited data exist on optimal dosing and range of activated partial thromboplastin time (aPTT) in this setting. A large trial of thrombolysis for acute myocardial infarction has reported an association between longer aPTTs and adverse outcomes. ⋯ For ACS patients who are treated with heparin, aPTT is highly associated with body weight. Longer aPTT within the first 12 hours is associated with adverse outcomes in ACS. Heparin dosing for ACS should be weight based.