aptt
Table of Contents
activated partial thromboplastin time (APTT)
see also:
introduction
- the APTT test measures the overall activity of the intrinsic coagulation pathway.
- performed by warming a thromboplastin reagent that contains phospholipid with an aliquot of the patient's plasma, and then recalcifying this mixture after a set incubation period.
- length of time taken for the mixture to clot is called the APTT and the normal range is 26-39 secs, depending on the analyser and the brand of reagent used.
causes of a prolonged APTT
- deficiency of one or more coagulation factors in the intrinsic coagulation pathway.
- presence of a lupus type coagulation inhibitor - an in vitro phenomenon giving falsely prolonged results in some patients.
- presence of heparin (but not LMW heparin)
aptt.txt · Last modified: 2009/09/01 04:45 by 127.0.0.1