Identifying and Reducing Pre-analytical Errors in the Medical Laboratory
Identifying and Reducing Pre-analytical Errors in the Medical Laboratory
Medical laboratory professionals must comply with stringent and robust standards in all aspects of their daily activities. The set of standards to which a laboratory must comply will differ depending on the scientific discipline of the laboratory, however, ISO 15189:2022 – Medical Laboratories – Requirements for quality and competence, applies to all medical laboratories. This recent version of the standard introduces increased focus on risk stratification and mitigation for patients and laboratory stakeholders, placing more emphasis on quality control to improve the accuracy and validity of the results obtained.
In a clinical chemistry laboratory, as in others, internal quality control is of upmost importance. Internal quality control (IQC) is the process used to ensure that all results produced are accurate, reliable, and reproducible. To achieve this, a laboratory must carry out checks on the pre-analytical, analytical, and post-analytical phases of testing.
The pre-analytical phase of laboratory testing includes collection, handling, transportation, storage, and preparation of samples. Even when the highest level of care is taken to ensure that all aspects of the pre-analytical phase are suitable and correct, errors can occur, exhibiting the need for clear and efficient quality control processes.
As part of our Acusera quality control range, Randox has developed the Serum Indices quality control to aid in the detection of the common pre-analytical error’s haemolysis, icterus and lipemia, collectively known as HIL. HIL interference can have disastrous effects on the quantification of many analytes, and it is therefore vital to determine levels of interference to improve laboratory efficiency and reduce the frequency of erroneous results. Figure 1 shows a graph of wavelengths at which each of these interferents may affect assays and the table below describes these forms of interference:
| Interference | Description |
| Haemolysis | The degradation of red blood cells causes interference between 340-440nm and 540-580nm. Red blood cells experience membrane disruption due to tangential stress which results in degradation of cellular integrity and the release of interfering cellular components such as haemoglobin, K+ ions and aspartate aminotransferase. Haemolytic interference may be evident in assays such iron, lipase, albumin, and creatine kinase. |
| Icterus | Interference as a result of high bilirubin concentrations, affecting assays measured between 400-550nm. The high bilirubin levels result in a yellowish pigmentation of the sample, caused by hepatic necrosis, sepsis, or several other conditions. Most prevalent in neonatal departments, icteric interference can cause inaccuracies in assays for phosphate, creatinine, cholesterol, triglycerides, and uric acid. |
| Lipemia | Interference caused by an aggregation of lipoproteins which affects the turbidity of samples. Lipemic interference can be cause by several mechanisms, the most common being the light scattering effect caused by aggregations of chylomicrons or other large forms of LDL. The larger the LDL molecule, the larger the lipemic effect. Lipemic interference is evident in assays measured between 300-700nm, however, interference increases as wavelength decreases. |
Classical determination of HIL interference took the form of a visual assessment. A sample was examined for tell-tale signs of one or more of these types of interference. However, these methods are subject to operator interpretation and lack harmonisation and uniformity across the industry. These signs are detailed in the table below and illustrated in figure 2.
| Interference | Visual indicator |
| Haemolysis | Red discoloration of serum samples which is directly proportional to the concentration of haemoglobin and other interfering erythrocyte components. |
| Icterus | Yellow pigmentation of serum samples increases proportionally to the concentration of conjugated and unconjugated bilirubin. |
| Lipemia | Increased sample turbidity proportional to lipid concentration. |
Modern clinical chemistry analysers have onboard HIL detection capabilities which offer objective, semi-qualitative or qualitative analysis of these forms of interference in a more precise and consistent manner. Automation of HIL detection improves laboratory throughput along with test turnaround times and enhances the reportability of the results.
Errors at any stage of the analytical process will result in retesting of the sample. Errors in the pre-analytical phase can have repercussions such as increased cost of repeated sample collection and testing, poor test turnaround times, and more seriously, delayed or incorrect diagnosis causing an exacerbation in the condition of the patient. To add to the adverse outcomes on patients, repeated testing places additional stress on laboratory resources and staff which ultimately affects every aspect of a laboratory’s daily activities.
We hope that by using the Acusera Serum Indices quality control and EQA scheme we can help to improve the accuracy of laboratory testing around the world and remove some of the excessive strain placed on laboratories and the professionals who continually strive for the highest levels of quality in all their work.
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Medical Laboratory Professionals Week – Industry Insight
As part of our effort to raise awareness of the hard work and dedication displayed by laboratory professionals around the world, we have been talking to individuals from the industry to discover what it is like to work in a medical laboratory environment.
Here, we talk to Dean, a mobile laboratory manager for Randox, based in the UK, to find out what it is like to work in his role.
Q: Let’s start with your name and job title please.
A: I am Dean Gordon and I’m a laboratory manager.
Q: So, what does a normal workday look like for you?
A: A normal day consists of ensuring all our laboratories have everything they need to follow our standard operating procedures and ISO standards. This ranges from ensuring we have enough staff and stock on site to reviewing end of day reports and KPI’s.
Q: What encouraged you to pursue a career in clinical diagnostics?
A: I actually never considered a career in clinical diagnostics. Previously, I worked in marine biology all over the world. During the pandemic I found myself back in Northern Ireland in limbo and Randox were advertising scientific roles on the radio. I thought I would use my science degrees in this moment and work in the lab until the pandemic finished. Over 2 years later, I now find myself still working with Randox and managing ten clinic labs in London and still testing for covid!
Q: What is the most challenging part of your job?
A: The most challenging thing I find is keeping an open line of communication with so many different departments. As our operations have continued to grow over the past 2 years, the more departments you find yourself dealing with, from operations and different clinics to HR and recruitment. There are so many cogs in the wheel and you need to work well with them all to keep it turning!
Q: What is your favourite thing about your role?
A: I love how quickly things move. Since I have started managing labs with Randox, we have opened dozens of new labs and are constantly adding new tests to our portfolio. You always have to be prepared and ready to go when the next new thing is announced. It keeps things exciting. I never feel that I’m bored or standing still in this role.
Q: And finally, why should others consider a career in clinical diagnostics?
A: When you hear feedback from a customer that their test results have helped save or prolong their life and how grateful and happy they are, that they decided to pay for their test – you remember what you are doing can change lives for the better.
We also got the opportunity to speak to Meadhbh, the Randox Clinical Laboratory Services Laboratory Manager, to hear about her work activities and opinions on working in a medical laboratory.
Q: Can you tell us your name and job title please?
My Name is Meadhbh Sheerin, and I am the RCLS Laboratory manager for all of RCLS.
Q: What does a normal workday look like for you at RCLS?
A: Everyday can be slightly different depending on what needs done. But everyday includes morning checks to identify work yet to be completed and ensure target sample turnaround times are met, dealing with customer queries, updating the LIMS system, adding new and bespoke tests to our equipment, managing reagent and other consumables, maintaining up to date SOP and ensuring laboratory staff follow them, and attending in management meetings scheduled. In addition to this I am responsible for hiring and training new staff, setting up new RCLS laboratories and managing the daily activities of other staff.
Q: What encouraged you to pursue a career in clinical diagnostics?
A: For me, it was that people’s health is a priority. Every day, we are saving lives and helping people with their diagnosis, prevent any health conditions, and help them get the right treatment if necessary.
Q: What is the most challenging part of your job?
A: Juggling everything in terms of staff, getting samples in and processed and reports out in time. There is an awful lot to do!
Q: What is your favourite thing about your role?
A: Every day is different and it’s challenging. It is rewarding to know that we are helping individuals to improve their health and that we are the future of diagnostics.
Q: And finally, why should others consider a career in clinical diagnostics?
A: I think everyone should consider a career in some sort of laboratory discipline because you are helping people improve their health and prevent further illness. Preventative care is better than a cure!
Like Dean and Meadhbh, there are millions of conscientious laboratory scientists and technicians which provide crucial testing services all over the world. Working in clinical diagnostics is an incredibly fulfilling career path, providing the opportunity to help people and save lives from a behind-the-scenes yet essential role. We would like to thank Dean and Meadhbh for taking the time out of their busy schedules to answer our questions. Finally, we would like to express our gratitude to all the Medical Laboratory Professionals who have worked tirelessly before, during, and after the pandemic and wish you all the greatest success in the future!
How can Randox help?
Randox Sales Reps are experts in their fields and are available to discuss your specific requirements.
Simply send us an email by clicking the link below and we will get in touch!
Medical Laboratory Professionals Week 2023
Medical Laboratory Professionals week is taking place from 23rd – 29th April 2023. This is an annual celebration to highlight and acknowledge the contribution of medical laboratory professionals and pathologists to medicine and healthcare. Whether carrying out routine testing or performing vital analysis during states of emergency, patients around the world rely on the hard work and dedication of medical laboratory professionals.
Medical laboratory professionals’ and pathologists’ work often goes unnoticed due to the ‘behind the scenes’ nature of their activities, but today we would like to shine a light on their work and highlight the importance of these individuals to medicine and global health. The role laboratory professionals play in healthcare cannot be understated and Randox would like to give thanks to those around the world who undertake this responsibility every day.
For most people, the process after a sample is taken is largely enigmatic. Therefore, we at Randox would like to elucidate the processes involved and the considerable effort displayed by laboratory staff.
After a sample is taken, it is then transported to a laboratory. Even this supposedly simple process requires careful consideration to ensure the sample is suitable for testing upon reaching the laboratory. Once received, laboratory staff carry out quality control checks to ensure the instrumentation to be used is functioning correctly and providing accurate results. The quality control procedure will differ depending on the scientific discipline but some form of validation of the test process is always required.
Once accurate and robust sample analysis has been carried out a pathologist examines these results or data and works to form a diagnosis. Using this diagnosis, a suitable therapeutic strategy can be determined and administered.
Test results are a major factor in a clinician’s decision for diagnosis and treatment, with 70% of all medical decisions being based on laboratory results. This demonstrates why diagnostics are so important and why Randox believes in celebrating those who make it happen.
As a major contributor to the diagnostics and healthcare industry, we are keenly aware of how important and hard-working medical laboratory professionals are, and the value they bring to the world. This week you’ll find articles featuring a short interview with a medical laboratory professional and a short educational piece on pre-analytical errors.
We hope everyone shares our enthusiasm for celebrating medical laboratory professionals and would like to thank all those who work tirelessly in medical laboratories around the world.
How can Randox help?
Randox Sales Reps are experts in their fields and are available to discuss your specific requirements.
Simply send us an email by clicking the link below and we will get in touch!