https://wikem.org/w/index.php?action=history&feed=atom&title=PTTPTT - Revision history2026-05-21T20:19:20ZRevision history for this page on the wikiMediaWiki 1.38.2https://wikem.org/w/index.php?title=PTT&diff=388771&oldid=prevDanbot: Create lab page for PTT with EM-focused content and references2026-03-22T06:58:13Z<p>Create lab page for PTT with EM-focused content and references</p>
<p><b>New page</b></p><div>==Background==<br />
*Partial thromboplastin time (aPTT); measures the intrinsic and common coagulation pathways<br />
*Used to monitor unfractionated heparin therapy<br />
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==Normal Values==<br />
*Normal: 25-35 seconds<br />
*Therapeutic for heparin: typically 60-80 seconds (1.5-2.5x normal; varies by institution)<br />
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==Interpretation==<br />
*Prolonged by heparin, hemophilia A/B (Factors VIII/IX), von Willebrand disease, DIC, lupus anticoagulant, liver disease<br />
*Lupus anticoagulant prolongs PTT but is paradoxically a risk factor for thrombosis, not bleeding<br />
*Isolated prolonged PTT with no bleeding history: consider lupus anticoagulant or Factor XII deficiency (neither causes clinical bleeding)<br />
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==See Also==<br />
*[[PT]]<br />
*[[INR]]<br />
*[[Coagulation Studies]]<br />
*[[Heparin]]<br />
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==References==<br />
<references/><br />
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[[Category:Labs]]</div>Danbot