HS TNI on iSTAT

I don't see how one would facilitate Deltas in regard to expected changes in hsTnI when it relates to MI.  I mean we have results and if they are consistently low then it is not an MI and if it starts to jump up then we would be expecting the result to continue climbing if in fact the patient is suffering from a MI, right?  Manufacturer's recommendations with the iSTAT suggest using symptoms and other identifiers in conjunction with hsTnI results ranging from 2.9ng/dL to 51ng/dL Anything below 2.9 would be a negative and 2.9 to 51 would be the intermediate (possibility) of MI with other identifiers and anything above the 52ng/dL to 1000ng/dL mark would most likely be a MI. 

Deltas are changes from a previous result to a current result, what difference are we looking at during an MI for us to call it a Delta?  2.9 to 10.0 is almost 30% jump, next test yields 29.0 and so on.  this would indicate that there is a MI in conjunction with symptoms and other results as hsTnl detects Troponin levels at even smaller measurements for earlier detection than the conventional cTnL I don't have a Delta flag just Critical ranges that flags the Physician. I suppose you could set it up but that would be in your Epic to fire alerts to notify the physician which would be critical ranges for us.

In regard to your iSTAT compared to your main analyzer I would just run a Concordance and see if there is an acceptable overlap.  e.g. Alinity hsTnl is <5.0 negative, 5.0-52.0 is intermediate and >52.0 to 5000+ (as it can be diluted) is MI.  iSTAT is <2.9 Negative, 2.9 to 52 Intermediate and >52 to 1000 is MI.  Our off site uses the same ranges (to avoid confusion in treatment) that the main lab uses because there is literally no significance between upping the 2.9 to 5.0 as a negative on the iSTAT.  The intermediate ranges are the same but the iSTAT upper AMR is 1000 so anything above 52 would be likely an MI, transport that patient to a facility that can better handle MI after initial intervention measures are in place to stabilize.

I hope I made some sense; I am not a great writer and usually need several revisions, but this will have to do.  Let me know if there is something wrong with my thought process, I love to learn.

For a delta comparison to be compared, the device would have to have the ability to store a patient history so that a new value could be compared to a previous.  I do not know of any POC analyzer that has that capacity.  Typically a delta flag is a function of an LIS, that would of course have that patient history of previous values and can display a failed delta flag when viewed.  But that is not going to populate back to the device/handheld, if that is what they are looking for.