Thromboelastography (TEG) platelet mapping assay measures maximal amplitude (MA) of clot firmness, reflecting maximal platelet function. The assay detects the reduction in platelet function, by antiplatelet medications, and presents it as percentage inhibition/aggregation.
Steps of thromboelastography platelet mapping assay
Login and perform e-test
Login to the TEG software by entering the username and password. Perform e-test for the two channels by putting TEG analyzer lever on test mode. Once the e-test is OK, put the lever back on load mode. Enter patient details and activator used in the channel [Figure 1].
Figure 1.
Login and perform e-test
Seat the cup in analyzer
Place cup in analyzer seat and slide the carrier up. Lock the pin with pusher by pressing 2-3 times and slide the carrier down. Seat the cup in analyzer [Figure 2].
Figure 2.
Seat the cup in analyzer
Collect patient blood in thromboelastography kaolin vial and sodium heparin vial
Put patient blood in vial containing kaolin activator up to mark one for basic TEG and in sodium heparin vial for platelet mapping [Figure 3].
Figure 3.
Collect patient blood in thromboelastography kaolin vial and sodium heparin vial
Add 10 μl of calcium chloride and 360 μl blood in a cup with specially designed pipettes [Figure 4].
Figure 4.
Add 10 μl of calcium chloride and 360 μl blood in cup with specially designed pipettes
Start the basic thromboelastography test
Slide the carrier up, put the lever on test mode and start the basic TEG test using only kaolin activator. Note the R, K, MA, lysis thirty values [Figure 5].
Figure 5.
Start the basic thromboelastography test
Start platelet mapping tests by adding distill water in p1, p2, p3 platelet mapping vials
Add 50 μl of distill water in p1 vial containing activator F in powder form. Add 100 μl of distill water in vial p2 and p3 containing adenosine di-phosphate (ADP) and arachidonic acid (AA) [Figure 6].
Figure 6.
Start platelet mapping tests by adding distill water in p1, p2, p3 platelet mapping vials
Seat the cup in second analyzer channer. Add activator F and blood in cup. Start the first platelet mapping test
Add 10 μl of diluted activator (activator F) from p1 vial and 360 μl of blood from sodium heparin vial, in the cup with the pipette. Mix them well [Figure 7].
Figure 7.
Seat the cup in second analyzer channer. Add activator F and blood in cup. Start the first platelet mapping test
Start second platelet mapping assay with adenosine diphosphate activator
Once the MA value of first platelet mapping assay is observed, start the second test by adding 10 μl of activator F (p1 vial), 10 μl of ADP activator (p2 vial), and 360 μl of blood in the cup [Figure 8].
Figure 8.
Start second platelet mapping assay with adenosine diphosphate activator
Start third platelet mapping assay with arachidonic acid activator
Once the MA value of the second platelet mapping assay is observed, start the third test by adding 10 μl of activator F (p1 vial), 10 μl of AA activator (p3 vial), and 360 μl of blood from sodium heparin vial in the cup [Figure 9].
Figure 9.
Start third platelet mapping assay with arachidonic acid activator
Observe the overlapping platelet mapping graphs of basic thromboelastography and platelet mapping for percentage inhibition/aggregation. Note the MA value of each test [Figure 10].
Figure 10.
Observe the overlapping platelet mapping graphs of basic thromboelastography and platelet mapping for percentage inhibition/aggregation. Note the MA value of each test
Part - II
Watch-out for platelet Mapping Analysis in Oct - Dec 2016 issue.