Rapid TEG and platelet mapping.

[sevoflurane]

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Anyone using it for the CT room and Trauma bay? If so, what are your experiences? Pitfalls?

 

[marenwhy]

TEG platelet mapping has some issues - see reference below
Platelet mapping assay interference due to platelet activation in heparinized samples. Am J Clin Pathol. 2014 Sep;142(3):331-8.
http://www.ncbi.nlm.nih.gov/pubmed/25125623

Regular/rapid TEG is fine though.

(I'm visiting from pathology - we can help w/ coag/testing issues 🙂)

 

[narcusprince]

How fast are the rapid TEG devices? The problem with the TEG devices I used in training were by the time the results came back you had a different set of problems to deal with. I believe a full tracing took maybe 25 minutes.

 

[Ignatius J]

How fast are the rapid TEG devices? The problem with the TEG devices I used in training were by the time the results came back you had a different set of problems to deal with. I believe a full tracing took maybe 25 minutes.

Used them at one place during residency after coming off pump. Worked great and definitely changed management sometimes. I would say they are a valuable tool. Hard to remember, but I think it took 10 minutes or so. So we would come off, do the volume/pressor thing, see we were in the clear, and send off the TEG.

 

[OB1🤙]

We have ROTEM. I really like it. If I suspect I'll need to give products, I run an EXTEM and FIBTEM while starting to warm. Useful results within 10 minutes, even while completely heparinized. I can then order any products as necessary, and have them in the room by the time protamine is in.

We use it for trauma as well. Great tool.

 

[sevoflurane]

Thx for the responses.

How fast are the rapid TEG devices? The problem with the TEG devices I used in training were by the time the results came back you had a different set of problems to deal with. I believe a full tracing took maybe 25 minutes.

R TEG adds tissue factor which greatly accelerates the results of the test.

We have ROTEM. I really like it. If I suspect I'll need to give products, I run an EXTEM and FIBTEM while starting to warm. Useful results within 10 minutes, even while completely heparinized. I can then order any products as necessary, and have them in the room by the time protamine is in.

We use it for trauma as well. Great tool.

HB: Are you guys running it in the OR or remotely with a computer displaying live results from the lab? When you say 10 minutes... you mean you can get R, K/alpha angle and general picture of what's going on... or 10 minutes start to finish? Have you found it more reliable than traditional data like fibrinogen/platelet levels and ACT, PT/PTT and INR? Has your product use decreased?

Specific to the CT room, have you seen a bump in your MA after rewarming is complete without the addition of platelets?

TEG is new to me in the adult heart room and trauma bay. Only used it in pedi hearts and liver transplants... a long time ago. Thanks for the input. 👍

 

[sleepallday]

Im not familiar with R TEG and platelet mapping but have been using Rotem for some time now. We run the tracing in the workroom and view the tracing live within the OR. Within 10 mins you start to get some useful data. The whole tracing takes about 45 mins, however, rarely do i need to let the test run in its entirety to know what is going on. Personally, I've found Rotem much more helpful then the standard coagulation assays mainly because of how quickly useful data is obtained compared to the other tests but also because of the qualitative nature of the test.

 

[OB1🤙]

So as a brief review for those not familiar with the technology- the ROTEM has a number of reagents and inhibitors you can run together depending on your clinical situation. The two I run on CPB are the EXTEM, which is tissue-factor activated (i.e. a test of the extrinsic pathway) and the FIBTEM, which is an EXTEM with platelet inhibitors added.

So the first thing you get is the EXTEM clotting time, similar to the r time on the TEG. If this time is prolonged, your "extrinsic" factors are deficient, and you order FFP.

Then you look at the FIBTEM amplitude, which looks at the fibrinogen contribution to the clot. This generally reaches something close to its final amplitude fairly quickly. An amplitude of around 7-8 mm is borderline, and represents a fibrinogen concentration of around 150.

Finally, look at the EXTEM alpha angle and amplitude. Both fibrinogen and platelets play a role here, so if the FIBTEM was normal but the EXTEM amplitude is low, you know you need platelets. If both were low, you'd get platelets and cryo (or fibrinogen concentrate). If FIBTEM was marginal but the EXTEM looks fine, no need to order cryo, the platelet function is robust. You'll know ten minutes into the clot how the clot is shaping up, although it'll continue to form and strengthen over time.

I have not seen a properly-run test mislead, so I think it's quicker than the usual tests and more meaningful. It does, however, involve a human pipetting reagents into specimen cups, so there is a small potential for human screw-up, which we've seen once or twice.

Our machine lives in the anesthesia techs' office which is literally across the hall from one heart room, and 20 feet away from the other. So while we're on pump I just go over there and quickly eyeball it as it runs. It has a built-in printer, and you can print while it runs (the vibration doesn't affect it unlike TEG) so if I really have my hands full I can ask the tech to print off a copy.

We still use traditional ACT for heparin management. We don't fuss with INTEM/HEPTEM usually. I consider the the APTEM (an EXTEM with added aprotinin) a worthless test, because all of our patients get anti fibrinolytics anyway, and if there is lysis, you'll see it on the EXTEM without needing to burn reagent on a confirmatory FIBTEM.

TL;DR version- ROTEM gives you valuable clotting information quickly, even while heparinized, and is like super awesome and stuff.

 

[OB1🤙]

I forgot to also say- ROTEM is insensitive to Plavix, which is to say the platelet inhibition of Plavix is overcome by the activation of the test, so you could have functionally deficient platelets but a normal ROTEM if they were Plavix loaded before surgery.

 

[sevoflurane]

...ROTEM gives you valuable clotting information quickly, even while heparinized, and is like super awesome and stuff.

Love it.

Thanks for the info. as I have exactly "zero" experience with rotational thromboelastometry. I'm used to seeing TEGs:

I guess the visual aspects of both tests differ.

Glad you find it useful in the OR and Trauma bay. The way it has been sold to me is that you get a lot of valuable information w/in a short period of time.
Adding platelet mapping apparently is helpful as well:

 

[sevoflurane]

Oh... and the heparinase TEG is super awesome and stuff to detect residual heparin effects (or rebound) after protamine has been given in the persistent oozer. 😉

 

[OB1🤙]

Better than ACT, do you think? I think ACT is a test where the "traditional" method is as reliable, and runs faster.

Forgot to answer you re: transfusion. What we've seen is a reduction in FFP given, and an increase in cryo. Overall transfusion rate is definitely lower.

Our surgeons have embraced our aggressive blood-conservation strategies fortunately, but if you have any who still want platelets and ffp for every pump run, this can help convince them that such an approach is unnecessary.

 

[sevoflurane]

Sorry 'bout the late response. A much needed storm left the pacific northwest ski resorts with some waist deep powder.

Better than ACT, do you think? I think ACT is a test where the "traditional" method is as reliable, and runs faster.

I really don't know as I've been using ACTs for all of my pump runs for my entire PP career. I'll let you know after my first 100 cases. I'm looking forward to seeing the results once I transition to R TEG and plt mapping.

To be honest, my old gig held a 3/3 STS rating with extremely rare bring backs. Everything was based on PT/PTT/INR, Fibrinogen and ACTs. Our product usage was slightly above national average however.

I know there are some pitfalls out there, so I'm not going to use TEG as an absolute although it will be a valuable tool in POCT.

I've heard that you can get a bump in your MA after rewarming.

I believe that TEG-platelet mapping can be reliable in quantifying platelet inhibition of plavix via ADP inhibition:

Thanks for the input HB. You are a great resource here on SDN.