Heparin Issues with ACT testing - ISTAT and Hemochron

We have been having issues as well with the istat ACTk cartridges. I had sent Abbott some info and they responded. Their report concluded that it was most likely the heparin. There were also some Xa results that were unexpected and our risk/safety department sent info to a third party to review. We are still awaiting their findings. We do not plan on switching to another device at this time since there is no indication the problem is with the cartridges. Please keep me posted.

Hello. We are currently investigating this in our system. I am on a joint project with our pharmacy. We haven't been able to isolate the issue to a brand/lot of heparin or an issue with a specific analyzer/lot of cartridges. We have found some patients with heparin resistance, but those are very few cases. We have reported cases with our iSTAT ACT-K and our Medtronic ACT+. I have not had any reported cases with my Hemochron Signature Elites ACT-LR. I do not run the ACT-HR on the Hemochron. 

We use iSTAT ACT-k in our system. At one of our hospitals, Pharmacy reached out about heparin potency issues and requested an investigation. There were several affected lots of unfractionated heparin involved.  All affected lots of heparin were assayed by our Special Coag dept and all came back with appropriate heparin concentrations (vials stated 1,000 U/mL; all lots recovered between 1,030 and 1,080 U/mL unfractionated heparin). We are preparing to do a study with varying concentrations of heparinized blood (using affected lots of heparin) to prove it's not the ACT-k cartridges. We feel pretty confident the underlying issue has more to do with heparin variation and/or patient variation, but we are not sure how to "prove" that.  If anyone has any additional information about the heparin supply, I would love to see that. 

We use the Hemochron GEM 100s for our ACTs. (Both the LR and the +)  At this time, we have not been made aware of any issues with the heparin they are using. 
What, exactly, is the issue you are having now with the iSTAT? Is it producing questionable results? Shifts? The two devices operate on different methodologies, but I'm not sure how that would change the dosing? If it's taking more heparin to produce the same result that used to be obtained at a lower dose, that sounds like a heparin issue. Maybe consult your medical director and get the pharmacy to weigh in?

This has been a topic of discussion for more than 6 months at least.  I would submit something formal through Abbott, as many before have done.  As the others in this thread have stated, the consistent explanation from Abbott has been heparin variation, but I don't know that there has been any formal statement, per se.  Only that in each case, any issues with devices and cartridges have been ruled out.  Also, because the complaints first arose last winter, I know there were also thoughts around heparin storage problems (freezing on loading docks), but I don't know that anything formally came of that theory.