i-STAT ACT k vs Hemochron

Kim,

We transitioned from the Hemochron to the i-STAT ACT cartridges cartridge back in 2003.  To summarize we run the ACT Kaolin cartridge in the "prewarm" mode" (we run our Celite cartridges in the "nonwarm" mode).  We used >480 sec as the target to go on bypass with the Hemochron.  Based on our correlation study and linear regression, the staff now use >450 sec for the i-STAT Kaolin cartridge. 

A few years after going live with the i-STAT we wanted to consolidate our ACT cartridges and asked the perfusion staff to do a side by side correlation between the Celite and Kaolin cartridges to see what the target range would be if they transitioned from the Kaolin the Celite cartridge.  Based on the linear regression analysis between the two types of cartridges, the staff would now need to use >535 sec on the Celite cartridges vs. >450 sec on the Kaolin.  The surgeons did not want to wait the extra time to go on bypass therefore we have continued with the two types of cartridges in-house. 

As an aside, we chose to run the Celite cartridges in the "nonwarm" mode because there was better correlation with our existing Hemochron times.  The "nonwarm" mode is really a misnomer.  The cartridges are warmed regardless of whether they are run in the "prewarm" or "nonwarm" mode.  i-STAT put a "fudge factor" in the "nonwarm" mode to equate the time to that of the Hemochron.  Thus, we did not have to change any of our target times for all of the other areas performing ACTs when we made the transition from the Hemochron to the i-STAT. 

If you have any questions I would be happy to speak with you live.  We served as a beta site when i-STAT was developing the test and spent the better part of a year running correlations in the various areas that perform the testing.  We did comparisons between the newer Hemochron device at the time (The Response), the Signature and the i-STAT run in both prewarm and nonwarm modes.

Thanks Andrea, can you send me your contact information? My email is listed above

Kim

Can you please share the istat vs hemochron data?  

michelle_johnson@memorial.org

Hello,

I would also like to see your data.

Thanks,

Reine

My Cardiac Cath Lab currently use Signature elite.  They use two different cartridges:

1. ACT-LR for Cardiac Cath patient

2. ACT Plus for open heart surgery done in the "Hybrid" room

I would like to use iSTAT ACT cartridges for both useages, thus eliminating having two cartridges.  Do you know of someone who has done a correlation between iSTAT ACT and Hemochron ACT-LR?

Thanks:

Robert Newberry, MT(AMT)

rnewberry@yumaregional.org

CELL: 928-246-9623

Point of Care and Education Specialist

ACT from CLN.pdf

The iSTAT Cartridge Information sheets in the iSTAT System Manual indicate both their Celite and Kaolin methods are calibrated to match Hemochron prewarmed tube test methods, but nothing about their cartridge methods.  But the attached graph on the last page of the 2002 article from the ACT guru Marcia Zucker might be of some help, but it only compares all Hemochron methods, tube and cartridge.

Hi,

Nice article but noted that it was published in 2002, prior to the reformulation of heparin. That caused big headaches as our providers were very upset that they started to notice that the ACT results were not as responsive to the new heparin.  Does anyone know if this study was repeated more recently?

Thanks,

Reine

What do you mean by newer heparins?  LMW heparin?

The change was in the way that the heparin activity is measured and led to a decrease in the potency of the heparin, not a change in the way the ACT's responded.  It now takes more heparin to see the same anticoagulant effect than it did 10 years ago.

Every ACT is different and the comparison is different in each institution and often in each department in each institution.  There is no substitute for having your clinicians do the comparison and determining the new target time based on data you have collected.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/dat.20434

Apparently in 2009, there were changes made in the pharmacy manufacturing that changed how heparin acted.  This affected ACT testing too.  I had just started at CHW and walked into this fire storm.

Reine

Reine - wow - I had no idea!

Andrea, could you please email me your data from the comparisons between iSTAT ACTs and Hemochron?

Thanks!

Gloria.maclean@stclair.org