YES, I thought it was just me having a difficult time.  I have had more errors with cartridges with Code 22 mixing errors too.

The sample well on the ACT cartridge is shaped a little differently than some of the other i-Stat cartridges and I think it somehow gets a trapped air bubble that blocks the sample.  We instruct staff to use a blunt needle and insert it slightly into the well to avoid this issue.  We also tell them to always have at least one more cartridge than they need at room temp so they don't have to redraw if they run into this issue.

I have tried a blunt needle and still have had an issue, not with every cartridge but with a few

No idea if this is "abbott approved"... but I've had good luck GENTLY tapping the cartridge flat on the counter. I don't know if it's due to surface tension or what, but it does seem to help. 

Have any of you reported the issue to Abbott? We have a case open with Abbott regarding Subtherapeutic ACT values after standard heparin dosing, the issue has been reported from multiple hospitals throughout the United States with many sites reporting cartridge fill issues.

I have also reported the subtherapeutic ACT values and reported the cartridge fill issue today. 

We just started having this issue last week with our current lot R25347 (6/11/26) and Abbott says they haven't had any other complaints.  I've advised the nurses to actually charge the cartridge instead of the "drip method" and haven't heard any further complaints.  I have not asked if they were having any analytical errors though.  I will have to investigate.

We have been having the same issue at our facility. We have had 7 cases so far from both the Cath labs and the OR. Multiple different operators, multiple different device serial numbers, and different lots of cartridges. The most recent lots have been R25295 & R25326. Our Pharmacy has also changed to a couple of different vendors for heparin, and we are still seeing this happen. We have opened an investigation with Abbott, which has been open for about a month now, but we have not received an update yet from Abbott. Like others have mentioned, we are only seeing this with a few patients. Both of these lots of cartridges had been in use for about a month with no reported issues, and then we began seeing issues. We have been keeping a spreadsheet that is shared between Nursing, Pharmacy and POCT updating with patient, heparin, and ACT information as each case arises, then we are sending that info to Abbott. Hopefully Abbott will be able to tell us something soon. 

I heard from our Abbott rep yesterday that over 1500 cartridges have been tested from multiple lots and they have yet to have an issue. Im still waiting for our specific report for our cartridges but that can take up to 4 weeks. 

I just received a New Lot ACT cartridges and they are filling better.