20-Minute Whole Blood Clotting Test (20WBCT) After Snakebite (WHO)
Reads a 20-minute whole blood clotting test after a snakebite.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Vessel the blood was tested in
- New, clean, dry ordinary glass
- Result after 20 minutes
- Not clotted (still liquid when tipped)
- When the test was done
- After the antivenom loading dose
- Hours since the antivenom loading dose
- 4
- Region
- South or South-East Asia
Result: Not clotted 4 hours after the loading dose: still within the usual 3 to 9 hours for clotting to return. Retest at 6 hours, 2 hours from now.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Vessel the blood was tested in
- Result after 20 minutes
- When the test was done
- Hours since the antivenom loading dose
- Region
How this is calculated
Citation
Warrell DA, for WHO SEARO. Guidelines for the management of snakebites. 2nd ed. 2016, pp. 123-125, 128-129, 142. WHO AFRO. Snakebite in Africa guidelines. 2010, pp. 60-61. India MoHFW. Standard treatment guidelines: snake bite. 2016, p. 29. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.