Description
Why It’s Done:
The CRT test is typically done to help evaluate the function of platelets, especially in conditions where there is abnormal bleeding or clotting. It can be used to:
• Diagnose platelet function disorders: Abnormal retraction time can indicate conditions like Bernard-Soulier syndrome or Glanzmann’s thrombasthenia, where platelets are unable to properly form or retract a clot.
• Evaluate bleeding tendencies: Prolonged CRT may be associated with von Willebrand disease or other clotting factor deficiencies.
• Monitor treatment response: The CRT can also be used to evaluate the effects of platelet-related medications or treatments for bleeding disorders.
• Assess pre-surgical bleeding risk: In cases where a patient has a history of bleeding complications, the CRT test may help assess clotting function before surgery.
Symptoms suggesting the need for this test include:
• Easy bruising
• Unexplained or prolonged bleeding (nosebleeds, gum bleeding, etc.)
• Heavy or prolonged menstrual bleeding
• Difficulty healing after injury or surgery
Preparation:
• The CRT test generally requires no special preparation. However, certain factors can affect the test results, such as:
o Medications that alter platelet function, including aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and blood thinners.
o Alcohol intake, which may also affect platelet function, should be avoided before testing.
o The test is often performed on a fasting patient, but this is usually more related to minimizing other factors that could affect clotting.
• Collection: Blood is typically drawn into a special tube, and the test is usually conducted under sterile conditions in a laboratory.
• Post-test care: If there are any concerns about bleeding after the blood draw, the technician or healthcare provider will provide instructions for care
