Biannual iStat Patient Correlations - Hct

Emily,  Our comparison has been good because we use Chem8+.  They use them in ER.  Patients there have not had any IV lines connected to them yet. A lot of times the doctor orders a basic metabolic panel and turns around and order Comprehensive panel to be done in the lab.  I use those duplicate results for my comparison. I collect these data and calculate them in June and December. I think comparing them all year round has an advantage.  I usually end up with 15-20 data samples which is better when calculating statistics.  One can detect any problem  ( if trending) with the i-STAT instead of just doing the comparison all at one time.   Our Surgery use CG8+ for their Open Heart Surgery.  The samples are not the best especially if they are hooked up to machines  and infusions that alter their blood samples.  We had that problem before until we decided that they cannot use the i-STAT HCT for transfusion. They can look at the HCT and monitor it. We have to run the sample in our main lab analyzer if they need transfusion. 

We also have issues with the H&H on our Istat's comparing to our main analyzers.  All of our Istat Blood gas results go out with the following comment- "ISTAT methodology for Hgb and Hct produces results less accurate than conventional laboratory methods.  ISTAT Hemoglobin and Hematocrit results may vary from those of laboratory methods by up to 2g/dL (Hgb) and by up to 4% (Hct).  Interpret results carefully and in correlation with overall patient condition."

We have had issues with the i-STAT Hemoglobin compared to the lab.  We use the comment "Point of Care Testing methodology intended for rapid screening purposes only.  Actual hemoglobin results may vary up to +/- 3 g/dL.  Clinical correlation required."

We too have seen this occasionally at our facility when comparing CG8s and our DxH.  If we see an exception during correlations, we include the statement "Hgb and Hct correlation results in Open Heart can run 2-4% lower than the Lab analyzer due to CPB mode and other factors. This difference would not change any clinical decisions. Results may not correlate within limits; alternate testing must be obtained for transfusion decisions.".

Depends on how far out the comparisons are.  I have been asked to run more samples.

We do not use the H&H on the iSTAT at all but 1 location for this reason. It does not compare well at all to lab instrumentation. We leave it on at our off site NICU for screening purposes.