Haematology Watch, Vol.7 , Issue 1.
LABORATORY HAEMATOLOGY
How to prevent an out-of-control result of Internal Quality Control?
Dr. Mehmood ul Hasan Malik
What is a Pathology Laboratory?
A Pathology Laboratory is a part of the world which is highly depended on and respected. Its result may mean life and death! And it functions at the cost of lot of systems, reagents, methods, and this is a costly stuff which takes time to build. The expected outcome is checked up regularly by internal and external quality watch dogs. If there is any fault in the whole testing process, it is dealt with very seriously and investigated accordingly. Detection of any fault happens at two stages: either before the result is out or when the result is released. We may sub-classify the first stage into further two stages: either when the patient specimen is tested or before it while running internal quality control (IQC).
Role of Prevention in Quality Checks:
t is an old adage that "Prevention is better than cure". And this holds very true in laboratory science as well where an error once happens leads to an array of long troubleshooting. So, how can we prevent an error to happen in first place before it is detected by our quality systems e.g. our IQC?
Another reason to prevent an IQC failure is that in modern analysers, the failed IQC result is saved, and you are either not able to delete it or not allowed to delete it by policy. So, once an error occurs, and the IQC data becomes red, you have to make a corrective action. This is a waste to time for a preventable error!
Thirdly, if you do not make a corrective action, the QC officer or an external quality check personnel can ask you that why did you not make a corrective action. Even if you make a corrective action, you may be asked why it happened at first place, especially if you are filling a corrective action form for the same reason again and again, or for different reasons showing that errors are arising at multiple areas in testing process!
Preventive strategy:
Following is a list of salient steps to be taken in order to prevent IQC failures:
WHILE READING A LEVEY-JENNINGS CHART:
1. Evaluate a Warning sign: violation of 1:2S Westgard rule.
2. Monitor a gradual change in the result of IQC before it becomes a Trend.
WHILE STARTING THE ANALYSER:
1. Verify that PPM is not due.
2. Reagents should be adequate in volume.
3. Reagents should be within expiry date.
4. Waste container should not be full.
5. Perform daily maintenance.
6. Address any issue mentioned on the analyser home screen.
7. Check if any new part replaced.
WHILE RECEIVING A NEW VIAL CONTAINER FROM MANUFATURER/SUPPLY CHAIN:
1. Verify that the cold chain was maintained.
2. Match name of the receipt with the vials supplied.
3. Correlate the information paper having control limits with the vial lot.
BEFORE OPENING A NEW IQC VIAL:
1. Verify that the IQC vial is not expired.
2. Check volume
3. See any visible clot
BEFORE SCANNING THE BARCODE:
1. Correlate the name of vial with the paper.
2. Correlate the level of vial with the paper.
3. Correlate the lot number of vial with the paper.
AFTER SCANNING THE BARCODE:
1. Verify that correct data has been successfully entered.
2. Allow the vial to come to room temperature.
WHILE MAKING LAB DEVELOPED IQC LIMITS:
1. Run controls at different times of working hours and by different lab staff to include possible variation.
2. Exclude those values which are beyond the acceptable limits given by the manufacturer.
3. If you are developing your own limits of IQC vials, use correct formulas for establishing Mean and standard deviation.
BEFORE RECONSTITUTION:
1. Bring the IQC vials to room temperature.
2. Use a calibrated micropipette.
3. Use the micropipette according to the instruction.
AFTER RECONSTITUTION:
1. Avoid making bubbles or foam if reconstitution is required.
2. Allow the vial to stand for a sufficient time to settle and mixed properly.
3. Check that the reagents are their dedicated slots.
WHILE LOADING THE IQC VIALS:
1. If running an analyser having specified slots for IQC vials e.g. some coagulation analysers, load the vials at correct position.
2. If there is an order of placing vials in a rack e.g. primer, then level 1, etc, then follow that order.
3. Verify that the mixing function is performed before running IQC in the analyser.
WHILE RUNNING MANUAL IQC:
1. Use a calibrated micropipette.
2. Mix the vial manually.
3. Remove any airbubble coming with the IQC specimen in the tip.
3. Visually check any gross variation in the amount of IQC specimen aspirated.
DURING TESTING IQC:
1. Verify that no air bubble is moving in the lines.
2. Verify that there is not clot in the lines.
AFTER TESTING IQC:
1. Do not interpret an LJ chart if any error message is given by the analyser.
2. Define the Westgard rules as they should be while reading the LJ chart.