Clinitek Status + Overcalling Blood?

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Hi All! 
Wondering if anyone is noticing a high rate of Trace - Intact and Trace - Lysed Blood results from the Clinitek Status +. We had a complaint filed from one site, and in evaluating results across all of my sites, noticed that around 17% of the results include a Blood value of Trace - Intact or Trace - Lysed. The IFU includes the statement that the significance of Trace may vary among patients, and we're currently going to put together an education campaign to ensure the testing procedure is being followed every time, but I wondered if anyone else had similar experience?

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Agree - I have seen this as well.  Lots of samples with trace-positive blood as the only abnormal result, and that does not confirm when sent for main lab confirmation on Iris analyzer.  While not great, it's better that than the other way around (undercalling the result).

Cleaning and drying the calibration bar may help.  Although you need to be very careful about scratching it.  Also wondering if perhaps a scratched calibration bar will cause this issue?

I will all but guarantee that the issue is that of not following protocol for dipping the strip and STARTing the analysis cycle. If the user dips the strip first, places the strip on the tray, and THEN presses start, the pad will react for longer than the prescribed 60 second time frame, leading to elevated or false positives (The pad does not stop reacting at the 60 second mark.). This is especially noticeable on Level 1 ("Negative") QC material and the anticipated Negative result will return Trace-intact and occasionally Trace-lysed values. 

The dipping of the strip is supposed to be simultaneous with the pressing of the START button. The eight (8) second lag time before the tray withdraws is kinda quick, especially for the less practiced among us.

That is a good point Andries and likely at the heart of the issue.  I strongly emphasize the correct "start then dip/blot/place" when training but staff inevitably adopt bad habits, especially when challenged by the 8-second window the analyzer provides.  This makes me curious about doing our own study to see just how many we may be overcalling.

This is a perfect topic since I am doing validation studies on Clinitek  Status +  for Urology clinic. One of my issue though was the discrepancy on calling 1+  on Clinitek Novus but Negative in Clinitek Status +.  Just curious if you have this issue. 

Andries is probly spot on, It's dipping before hitting start or not cleaning the strip insert well enough between tests. Ya gotta get into the crack!

First take a look at the QC from this instrument. Is there a higher predominance of RBC issues? Then check to see if there is an operator who has the majority of the positive RBCs.

I notice increased intact RBC with patients and QC when:
1) the RBC pad is compromised -leaving the lid off the strip container allows room moisture to sit on the reagent pad. Toss the bottle and start over; and
2) lack of blotting the reagent pad prior to sitting on the platform. Blotting helps get rid of extra sample between the reagent pads. Carry over can cause issues with the Multistix 10SG because the blood pad changes from yellow to green and the next reagent pad to the blood pad is the pH, which goes from green to yellow.

Robin Tricker, MT(ASCP)
Ancillary Testing Coordinator
Roudebush VA Medical Center
1481 West 10th Street, Indianapolis, IN 46202
Phone: 317-988-2219

Agree with most of the posters here. The process of pressing START, and then wetting the strip is highly important. The strip will overdevelop if this isn't followed. And also the timely cleaning of the table and calibration strip could lead to issues. Improper blotting/overly wet strips going into the instrument also leads to problems. We've experienced all of these and increased accountability into cleaning up these issues has resulted in more consistent, expected results.

Thank you all! I agree that the technique is the most likely culprit, but it helps to know it's an issue seen elsewhere too! Currently having "secret shopper" evaluate testing procedure for compliance, as all of the sites in my program are ambulatory.

I've seen this problem with QC when the Negative control is cold and not room temp. Also, API just published their 2nd Event results for UA. Check your proficiency testing results too. 

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