Introduction to Point of Care

What is Point of Care Testing?

Point-of-care testing (POCT) is defined as medical testing at or near the site of patient care by specially trained healthcare professionals. These are tests which can be performed at the bedside and typically involve blood and urine testing. The goal of POCT is to collect the specimen and obtain accurate results in a very short period of time at or near the location of the patient.

POCT is often accomplished through the use of transportable, portable, and handheld instruments (e.g., blood glucose meter, INR meter). Bench analysers are also available for blood gas, pH, electrolyte, metabolite and haemoglobin measurement. Urinalysis analysers are also available for rapid and accurate urine testing.

POCT is carried out in a wide range of settings, in primary care, the community and secondary care, supporting the delivery of the right care in the right place at the right time.

What are the advantages of POCT?

The main aim, and benefit, of POCT is to bring the test conveniently and immediately to the patient. This increases the likelihood that the physician and care team will receive the results quicker, enabling clinicians to support the timely diagnosis, monitoring and treatment of patients.

What are the disadvantages of POCT?

There are many limitations with POCT testing if analysis procedures are not adhered to. It is essential that POCT is undertaken correctly to ensure accurate and reliable results.

Poor quality of analysis, poor record keeping, a lack of report interpretation, failure to detect abnormal results, unauthorised processing and inappropriate testing are critical areas that directly affect patient results and care.

POCT devices are unable to detect lipaemic, icteric and haemolysed samples. According to several studies, visual detection is inadequate to determine the presence of lipaemia in whole blood samples. Similarly, haemolysis is impossible to visually detect in whole blood samples and can heavily impair results produced.

Result quality is often directly related to sample quality; a poor sample or incorrect analytical technique will yield poor results.

For example, poor blood gas sample preparation handling can often result in incorrect blood gas, pH, haemoglobin and potassium results as a consequence of room air contamination, settling of the cells and haemolysis respectively.

Put simply, an incorrect test result can result in the wrong treatment and potentially life threatening consequences.

What is Internal Quality Control?

Internal quality control is a means of checking that the device in question is able to measure within predefined, controlled limits to determine its functionality and the reliability of patient results produced from that device.  The periodic analysis of suitable control material can provide assurance that the system is working correctly and is producing reliable results.

It is essential that the produced QC results are recorded and stored appropriately.

What is External Quality Assessment?

External Quality Assessment is defined as a system for objectively checking the laboratory’s performance using an external agency or facility.

This involves the analysis of samples from an external source with unknown values, the results of which are subject to peer group assessment and analysis to compare results across multiple sites.

EQA participation is a critical component in assuring the quality of results and provides valuable data which has the following benefits:-

 

·         It allows comparison of performance and results among different test sites;

·         It provides early warning for systematic problems associated with kits or operations;

·         It provides objective evidence of testing quality;

·         It indicates areas that need improvement;

·         It identifies training needs.

 

EQA helps to assure physicians, patients and health authorities that the laboratory can produce accurate and reliable results.


Page updated: 12/11/14 | Updated by: Daniel Ogola