aPTT (Activated Thromboplastin Time)
20-36 sec.
Screens for deficiencies and inhibitors of all factors except VII and XIII.
Used to monitor heparin therapy and screen for coagulation disorders.
Should be between 1.5 and 2.5 times normal when the client is receiving heparin therapy; if the value is prolonged (longer than 90 sec), the client is at risk for bleeding.