====Required lab test====
{{#ifeq: {{{PT}}} |no|None necessary.|Prothrombin time (PT or INR):
*Inpatients: within 24 hours
*Outpatients with a healthy liver: Within 2 weeks
*Outpatients with liver disease and no additional acute disease since then: Within 1 week}}
====Lab interpretation====
*INR {{#ifeq: {{{PT}}} |, if taken,||}} should be corrected if over 2.0
*If ''partial thromboplastin time'' (aPTT or APTT) has been taken, it should be corrected if over 1.5 times its normal upper limit.
*If ''platelet count'' has been performed, transfusion is indicated if it is below 50 x 10<sup>9</sup>/L (equals 50,000/µL).