The combination of an APTT and a PT as coagulation 'screening tests' may not detect all clinically significant bleeding disorders; the sensitivity of a detailed clinical assessment is high.

In the pre-operative assessment of patients, these tests should not be routinely performed. However, in a patient with a positive bleeding history or a clear clinical indication (e.g. liver disease), these tests are required.

Assessment of the risk of bleeding in a preoperative patient should include review of medications (including complementary medicines), a bleeding history assessment and physical examination. There are a number of bleeding assessment tools (BAT) available for this purpose.

Example of screening questions for bleeding history include questions concerning:

1. Undue bleeding after cutting or biting the tongue.

2. Significant easy bruising.

3. Prolonged bleeding after dental extractions, or re-bleeding.

4. Prolonged bleeding or excessive bruising after any surgery (major or minor).

5. An adequate menstrual history, including family history of excessive or prolonged menses.

6. Family history of post-op bleeding requiring transfusion.

7. Current or recent medications including: aspirin, other analgesics, cold medications, warfarin.

8. Excessive bleeding from umbilical cord stump.

If the bleeding history and examination is negative, then no coagulation studies may be necessary prior to minor procedures.

If the bleeding history is positive or if the surgery is likely to impair haemostasis e.g. cardiac surgery, then coagulation testing is recommended. This testing (including testing in addition to routine coagulation studies) will be guided by clinical history, medications, bleeding history, family history and the type of procedure. Haematologist advice recommended.