Maximum Defect Velocity in Intact Red Blood Cells (IVS Defect Velocity)
This test measures how quickly red blood cells (RBCs) lose flexibility or deformability, which is important for their ability to pass through narrow blood vessels. Defect velocity helps assess RBC membrane integrity and can be relevant in conditions affecting RBC shape or function.
["This test evaluates RBC flexibility, which may indicate underlying blood disorders."]
Key facts at a glance
- LOINC
- 20368-7
- Short code
- IVS defect Vmax DOP
- Synonyms
- IVS defect Vmax DOP
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-doppler
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms like fatigue, shortness of breath, or signs of anemia, or if you have a known condition that affects red blood cells, such as hereditary spherocytosis or other RBC membrane disorders. It can also be part of a broader evaluation for conditions that impact blood flow or circulation.
What Does the Test Involve?
The test typically requires a small blood sample drawn from a vein in your arm. The blood is then analyzed in a specialized lab to measure how quickly RBCs lose their ability to deform under stress, which is reflected in the defect velocity measurement.
What Do Results Mean?
Results are not provided as a single numeric range in this test, as it evaluates a qualitative measure of RBC deformability. High defect velocity may suggest increased rigidity in RBCs, which could be linked to conditions impairing circulation or oxygen transport. Your provider will interpret results in the context of your symptoms and overall health.
What Are Possible Causes?
Elevated defect velocity may be associated with hereditary RBC disorders (e.g., hereditary elliptocytosis, hereditary spherocytosis), certain medications, or conditions that damage RBC membranes. It can also be seen in chronic diseases like diabetes or kidney disease that indirectly affect RBC function.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose or monitor conditions affecting RBC membrane integrity and deformability. While not always definitive on its own, it can help confirm or refine diagnoses when combined with clinical findings, other lab tests, and patient history. For example, it may be useful in assessing whether RBC abnormalities are causing circulation issues or contributing to symptoms like fatigue or leg pain.
Short name
IVS Defect Velocity Max
Frequently asked questions
What does an abnormal result mean?
How often will I need this test?
Can lifestyle changes affect this test result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy