Aspirin Tolerance Test (ASA Tolerance Test, Bleeding Time Aspirin Tolerance Test)

Norm of Aspirin Tolerance Test (ASA Tolerance Test, Bleeding Time Aspirin Tolerance Test)

Requires interpretation. Normal baseline Ivy bleeding time is 2–7 minutes. One study demonstrated bleeding time in normal clients to increase from 2.5 to 4.2 minutes at 2 hours after aspirin ingestion. Bleeding time should return to baseline level by 96 hours after aspirin ingestion.
Bernard-Soulier syndrome, collagen vascular disease, Cushing's disease, disseminated intravascular coagulation, Glanzmann's thrombasthenia, gray platelet syndrome, hypersplenism, thrombocytopenia with immunosuppression, and von Willebrand's disease. Drugs include anticoagulants (oral), indomethacin, phenylbutazone, and platelet aggregation inhibitor drugs (aspirin, clopidogrel, eptifibatide). Herbs or natural remedies that may inhibit platelet activity include feverfew (Tanacetum parthenium), Ginkgo biloba, garlic, ginger, ginseng.
Drugs include 1-deamino-8-d-arginine vasopressin (DDAVP).


Description of Aspirin Tolerance Test (ASA Tolerance Test, Bleeding Time Aspirin Tolerance Test)

The Ivy bleeding time test is performed before and after aspirin ingestion to evaluate the drug's effect on platelet function. In normal clients, aspirin ingestion has minimal influence on bleeding time.


Professional Considerations of Aspirin Tolerance Test (ASA Tolerance Test, Bleeding Time Aspirin Tolerance Test)

Consent form NOT required for most laboratories.

Bleeding, ecchymoses, hematoma.
In clients who require upper-extremity restraints, have edematous or very cold arms, or are prone to keloid formation. This test should not be performed if there are contraindications to placing or inflating a blood pressure cuff on the arm (casts, rash, arteriovenous fistula). Other contraindications include platelet count <50,000/mm3, severe bleeding disorders, skin infectious diseases, senile skin changes, or medications containing acetyl groups, such as those containing aspirin, within the previous 5 days.



  1. See Client and Family Teaching.
  2. Obtain povidone-iodine solution, a blood pressure cuff, a lancet, a stopwatch, and filter paper.



  1. Cleanse the volar aspect of the forearm with povidone-iodine and allow it to dry completely.
  2. Place the blood pressure cuff on the upper arm and inflate to 40 mm Hg.
  3. Make two small incisions 2–3 mm deep on the prepared site. Start timing with the stopwatch.
  4. Remove blood from the wound with filter paper every 15 seconds until bleeding stops. Stop timing with the stopwatch.
  5. If bleeding time is more than 10 minutes, do not proceed further because this test would be contraindicated.
  6. Administer 10 grains (adults) or 5 grains (children weighing less than 32 kg) of aspirin orally.
  7. Repeat steps 1 through 5 after 2 hours.


Postprocedure Care

  1. If bleeding time is normal, apply a Band-Aid to the site. If bleeding time is prolonged, apply a pressure bandage to the site.
  2. Assess the site(s) for bleeding every 5 minutes for ½ hour. Observe for signs of site infection until healed.


Client and Family Teaching

  1. Do not take aspirin for 5 days before this test.
  2. Bring reading material or some other diversion because the test takes 2–3 hours.


Factors That Affect Results

  1. The most sensitive and reproducible measurements may be those taken from a horizontal incision.


Other Data

  1. The depth of the puncture with the lancet is difficult to standardize and results in poorly reproducible bleeding times.