monitoring heparin
Last reviewed 01/2018
Heparin is monitored by measuring the APTT.
For established thromboembolism, the APTT should be prolonged 1.5 - 2.0 times normal. The therapeutic response lessens if the APTT is less than 1.5 times normal.
Bleeding risk at this level is low unless there are predisposing risk factors. High risk patients should be treated at the lower end of the range.