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Specialist Advice — 8 minutes

Are you familiar with bedside testing devices, also known as point-of-care testing (POCT)?

Raymond Lepage, PhD, Doctor in Biochemistry
Raymond Lepage, PhD, Doctor in Biochemistry
Science popularizer

Recently, POCT devices have been booming in popularity. It wasn’t always this way: in the early 1970s, the only remote tests available were carried out entirely by hand. They were based on test strips used by doctors or nurses to measure certain urinary parameters (pH, proteins, etc.) or urine tests to measure glucose and ketones in diabetic patients.

At the time, several drug stores were already offering on-site pregnancy tests, including the famous Pregnosticon, which was based on the same technology being used in hospital laboratories.

The technological revolution

The arrival of blood glucose monitors

The first revolution came with the introduction of blood glucose monitors (e.g., the Dextrometer) in hospitals and homes. These devices required only a single drop of blood taken from the fingertip. Their use was intended to reduce the often long processing times in central laboratories.

Today’s devices are vastly different from those of that time in terms of user-friendliness, blood volume required and accuracy of results. What’s more, results can now be entered directly into a patient’s electronic file. Today, more than 1,500 blood glucose measurements a day are sent back to the CHUM’s central laboratory!

1980-2000: Electronic miniaturization, microfluidics and nanotechnology

The years 1980 to 2000 saw the progressive introduction of POCT devices to measure cholesterol levels, monitor patients on anticoagulants, evaluate changes in vital parameters (arterial gases, glucose, electrolytes, etc.) in the operating room or intensive care unit, and detect illicit drugs directly in the emergency unit.

And it doesn’t stop there! Recent advancements in electronic miniaturization, microfluidics and nanotechnology make it possible to imagine cutting-edge, virtually complete laboratories that fit in a simple suitcase.

Real-time data transmission

With regard to patient monitoring, blood glucose analyzers planted on or underneath the skin are already on the market and enable the analysis of glucose levels in problematic patients every five minutes for one week. Results are instantly transmitted to the patient’s health care team via smartphone.

Infectious diseases

POCT devices also facilitate the diagnosis of several infectious diseases. Some devices can analyze a person’s DNA outside the laboratory in a matter of minutes to detect bacterial and viral strains.

One such device is particularly useful during flu season, as it can detect a range of bacteria and viruses responsible for many respiratory infections. Currently, the overuse of antibiotics is believed to be largely responsible for the emergence of bacterial strains that are resistant to most treatments on the market. What’s more, antibiotics are often prescribed as a knee-jerk solution to treat respiratory tract infections that are viral rather than bacterial in origin.

The problem is that such multi-drug-resistant and highly contagious strains put populations at great risk. The situation would be simpler if clinicians used POCT devices to reliably determine the nature of the problem before the patient even leaves the clinic.

For example, there are currently a few POCT devices that are capable of detecting group B streptococcus, which is responsible for a large number of throat infections. There are also other tests available to screen for influenza, mononucleosis and various sexually transmitted infections.

Read more: Biron improves diagnostic procedure for strep throat with its molecular test

The COVID-19 pandemic

All pandemics such as the one caused by COVID-19 put enormous pressure on laboratory resources. How can affected individuals be rapidly diagnosed in populations with hundreds of thousands or even millions of people? At the start of the pandemic, the inability to test individuals in time was responsible for an accelerated spread of the infection in most Western countries. This factor certainly contributed to the severity of the crisis in Quebec’s residential and long-term care centres.

Point-of-care testing will be absolutely essential in all situations where quick results are required (immediate confinement versus the quick return to work of potentially contaminated employees, care units in remote regions, etc.). Currently, rapid screening devices for SARS-CoV-2 RNA (chromosome) are available on the market, including an entirely Canadian model (Spartan Bioscience). Other POCT devices are also being used for serological testing (i.e., detection of antibodies to the COVID-19 virus) in different parts of the world. Only these technologies will allow public health authorities to carefully monitor the pandemic in different populations.

Ream more: COVID-19 screening tests: How does it all work?

The skepticism of health care professionals

However, the reliability of point-of-care testing has its skeptics among laboratory professionals. Although medical devices used in this country must be approved by Health Canada (i.e., manufacturers must prove that their products meet the specifications), a look at the list of recalls shows that a product’s approval does not necessarily guarantee its effectiveness. In addition to the problem of manufacturing defects, products must be stored under proper conditions and used before their expiry date, following the instructions to the letter.

Maintaining quality is an inescapable reality in laboratory medicine. It is essential to put in place comprehensive quality assurance programs that include regular product checks (internal and external quality control, reagent traceability, error source documentation, certification and recertification of personnel, etc.). All are subject to regular inspections by competent bodies (Accreditation Canada, BNQ, ISO, etc.). As a result, POCT devices may not be adequate for the task if they are used outside a rigorous framework by untrained personnel.

Ask questions

The next time that point-of-care testing is used for you or someone close to you, do not hesitate to ask questions about the quality assurance process. After all, your doctor will use this information to make a diagnosis or choose a treatment – decisions that are not without consequences. For the same reasons, be extra vigilant with POCT devices advertised on the internet which are intended for direct consumer use. Your health is at stake.