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Platelet Count

Item Value
Clinical Questions Is my patient refractory to platelet transfusions due to alloantibodies?
Approval req'd? No
Available Stat? Yes
Test code PLT, CBC , CBCD, PLTM
Performed by Parnassus, Mission Bay & Mt. Zion Hematology
In House Availability Test available 24 hours per day 7 days per week
Method Flow cytometry and/or Phase microscopy
Collection Instructions Collect the specimen in a blue top (citrate) tube if platelets are repeatedly found to clump in samples collected in a lavender top (EDTA).

When platelets clump in both EDTA and citrate tubes, and the count is < 100 and a physician specifically orders the procedure, a count will be run on a fingerstick sample collected directly into a Thrombo-tic¨.
Container type Lavender top
Amount to Collect 1 mL blood
Sample type EDTA whole blood
Preferred volume 1 mL blood
Min. Volume 250 µl in pedi-bullet
Units x109/L
Normal range 140-450 x109/L
Critical value ≤ 10 x109/L (always called)
≤ 25 x109/L Called if new finding within previous 24 hours.
Turn around times STAT 1 hour, Routine 4 hours
Additional information The less precise manual method is usually performed and billed (PLTM) when required by an intrinsic abnormality of the specimen.

In the presence of clumping, only platelet counts > 100 x109/L are reported.

Platelet estimates derived from a manual review of a peripheral blood slide are released only in cases in which the presence of white blood cell fragments and high numbers of giant platelets negate the use of both the automated machine and phase platelet analysis for generation of a platelet count. Manual platelet counts at low platelet values are subject to high precision errors because of the low number of platelets counted. Therefore, clinical correlation is advised.hhh
Last Updated 1/27/2015 2:37:28 PM
Entry Number 750
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