Point-of-care testing

Point-of-care testing (POCT), or bedside testing is defined as medical diagnostic testing at or near the point of care—that is, at the time and place of patient care. This contrasts with the historical pattern in which testing was wholly or mostly confined to the medical laboratory, which entailed sending off specimens away from the point of care and then waiting hours or days to learn the results, during which time care must continue without the desired information.

Point-of-care tests are simple medical tests that can be performed at the bedside. In many cases the simplicity was not achievable until technology developed not only to make a test possible at all but then also to mask its complexity. For example, various kinds of urine test strips have been available for decades, but portable ultrasonography did not reach the stage of being advanced, affordable, and widespread until the 2000s and 2010s. Today portable US is often viewed as a "simple" test, but there was nothing simple about it before the technology was available. Similarly, pulse oximetry can test arterial oxygen saturation in a quick, simple, noninvasive, affordable way today, but in earlier eras this required an intraarterial needle puncture and a laboratory test; and rapid diagnostic tests such as malaria antigen detection tests rely on a state of the art in immunology that did not exist until recent decades. Thus, over decades, testing continues to move toward the point of care more than it formerly had been. A recent survey in five countries (Australia, Belgium, the Netherlands, the UK and the US) indicates that general practitioners / family doctors would like to use more POCTs.

The driving notion behind POCT is to bring the test conveniently and immediately to the patient. This increases the likelihood that the patient, physician, and care team will receive the results quicker, which allows for immediate clinical management decisions to be made. POCT includes: blood glucose testing, blood gas and electrolytes analysis, rapid coagulation testing(PT/INR, Alere, Microvisk Ltd), rapid cardiac markers diagnostics(TRIAGE,Alere), drugs of abuse screening, urine strips testing, pregnancy testing, fecal occult blood analysis, food pathogens screening, hemoglobin diagnostics (HemoCue), infectious disease testing and cholesterol screening.

POCT is often accomplished through the use of transportable, portable, and handheld instruments (e.g., blood glucose meter, nerve conduction study device) and test kits (e.g., CRP, HBA1C, Homocystein, HIV salivary assay, etc.). Small bench analyzers or fixed equipment can also be used when a handheld device is not available—the goal is to collect the specimen and obtain the results in a very short period of time at or near the location of the patient so that the treatment plan can be adjusted as necessary before the patient leaves. Cheaper, faster, and smarter POCT devices have increased the use of POCT approaches by making it cost-effective for many diseases, such as diabetes, carpal tunnel syndrome (CTS) and acute coronary syndrome.

Technology

Many point-of-care test systems are realized as easy-to-use membrane-based test strips, often enclosed by a plastic test cassette. This concept often is realized in test systems for detecting pathogens. Very recently such test systems for rheumatology diagnostics have been developed, too. These tests require only a single drop of whole blood, urine or saliva, and they can be performed and interpreted by any general physician within minutes.

Benefits

Major benefits are obtained when the output of a POCT device is made available immediately within an electronic medical record. Results can be shared instantaneously with all members of the medical team through the software interface enhancing communication by decreasing turn around time (TAT). A reduction in morbidity and mortality has been associated with goal-directed therapy (GDT) techniques when used in conjunction with POCT and the electronic medical record.

POCT has become established worldwide and finds vital roles in public health. Many monographs in the Thai and Indonesian languages emphasize POCT as the normal standard of care in disaster situation.

Potential operational benefits of POCT:More rapid decision making and triage, reduce operating times, reduce high-dependency, postoperative care time, reduce emergency room time, reduce number of outpatient clinic visits, reduce number of hospital beds required, ensure optimal use of professional time.

Challenges

Although there are many benefits of using POCT devices in terms of their convenience, establishing a POCT indeed is a challenging job. Some of the biggest challenges for the person holding this post are gaining physician and nurse allies and turning non-laboratorians into testing personnel, all while ensuring adherence to best laboratory practices and regulatory agency standards. POCT implementation requires a systematic approach which involves all stakeholders. Most of the healthcare organization are unfamiliar with the POCT due to which very less efforts are made to establish a complete POCT set up.

POCT: CHALLENGES

• Management
• Responsibility
• Location
• Staff training and competency maintenance
• Reliability of POCT results
• Quality Control
• POCT Challenges for End Users:
• Data Management
• Noncompliance with procedures (specimen labeling, QC, proficiency testing etc.)
• Infection Control
• Billing

MANAGEMENT OF POINT-OF-CARE IN THE HOSPITAL Management of POCT is challenging – there can be dozens of sites, hundreds of POCT devices/kits, and thousands of operators to manage to assure quality of testing. The first challenge in developing a strategy to manage POCT involves building a competent interdisciplinary POC management team including the laboratory, physicians, and nurses. The POC team should hold the ultimate responsibility for determining the test menu, selecting technologies, establishing policies and procedures, ensuring training and regulatory compliance, and providing advisory assistance to the end users of POC technologies. After establishing a POC team a management structure should be build that is responsible to implement new initiatives and to perform corrective action where necessary.

WHOSE RESPONSIBILITY? Who holds the responsible for the test results performed outside the laboratory - the operator, the laboratory or the manufacturer? The rational answer to this questions would be: all three parties must accept their responsibility toward assuring the accuracy of every single result. Clinician is the person who is going to take the decision on patients condition whether the test is performed in the laboratory or bedside, whatever the results are obtained expected or unexpected regarding the treatment or repeating test or further work up that may be necessary to arrive at the right diagnosis. The clinician needs to establish his confidence on the reliability of the results obtained out of POCT

TRAINING USERS IN POCT Should cover theory and practice: – Storage of QC material – Preparation of QC material – Appropriate QC frequency for each test – Principles and practice of QC testing – Remedial actions for failures – Recording and documentation of actions Once the procedure manual has been created it is necessary that all users have read it and this process should be documented. The salient features for each test need to be understood and demonstrated during training. This would be followed by a competency assessment which would be the exit examination before the healthcare worker can test patients.

CHALLENGES IN TRAINING… MANAGEMENT OF TRAINING �Number of staff requiring training be in the thousands �A high turnover rate Nursing staff can be transferred between different departments �Poor communication between nursing administration and POC coordinator. Diverse educational backgrounds

NON COMPLIANCE WITH PROCEDURES The majority of staff involved in the POCT are from the non-laboratory side and may be unaware of the routine laboratory procedure regarding calibration, maintenance of instruments, quality control processing and analysis of QC data, sample collection procedure and patient preparation before sample collection. This may pose a threat of non-compliance with standard operating procedure that may contribute to errors in POCT.

RELIABILITY OF POCT RESULTS Questionable quality can occur, given the variety of educational and experience levels and turnover of staff that perform the tests. Greater inter-individual variability in results (compared to central laboratory testing) is common. Waived category does not guarantee reliability. Simplicity is deceptive and there are many ways that staff can inadvertently generate a wrong result with waived or “simple” tests. POCT results are not necessarily comparable to central laboratory results – Standard methods may not be used in POCT and thus it may not be possible to compare results across sites (e.g. when patients travel and are tested at different sites, or when treatment protocols derived from more accurate results are being followed). Differences in specimen types, (e.g. serum, plasma, or whole blood,) may also affect results between traditional central laboratory methods and POCT. Thus, clinical protocols based on central laboratory results may need to be revised when utilizing POCT results. POCT kits and devices may not be FDA approved for all uses that a similar test in the central laboratory can be used for

POCT CHALLENGES OF END USERS Competencies - Waived vs Non-waived • Underestimation of risk by the user – False perception of infallibility – Pressures of a busy clinical environment • Training and competency verification – Large number of users – Diverse educational backgrounds • Technical aspects – Many locations to control (metrology, documents…) – Adequate storage space to store specimens to repeat the tests between the last successful QC and a failed QC – Clinical management on receipt of results does not allow the system to be out of control.

INFECTION CONTROL Standard (universal) infection control precautions the prevention of occupational exposure to blood-borne viruses, the wearing of gloves and other protective clothing, and the prevention of sharps injuries prevention of cross infection with blood-borne viruses, including selection of appropriate lancing devices safe handling and disposal of healthcare waste, including sharps Hand washing is generally considered the most important measure to prevent the spread of infection. Hands should be washed before patient contact, after patient contact and after contact with body fluids irrespective of whether gloves are worn or not.

POCT CHALLENGES OF THE DATA MANAGEMENT POCT data is available at the place of testing but once the patient is shifted form intensive care units or emergency department to general wards or subsequent follow up visit in OPD, the data of POC testing is not available if the devices are not well connected with LIS and HIS. To make this reports of test available at other sites than POC these devices needs to be connected with LIS and HIS. POCT results in the EMR pose additional levels of complexity. Connecting POCT devices to an EMR, for example, requires a computer interface and ongoing maintenance at additional costs. Many POCT devices must pass results through a proprietary data manager (from the specific manufacturer of the device) through a laboratory information system, then into the EMR.

LOCATION POCT is conducted at many different locations and can be under different laboratory licenses and medical directors. In a large health system with many testing locations, the display of dozens of glucoses would be extremely confusing in the EMR. A better option is to link this information to each result but suppress the display of the site information such that any clinician or inspector can right-click the mouse to find the analyzing site, address and medical director at the time the test was conducted.

BILLING POC testing are associated with high cost per test due to their rapidity of result generation and consumable cost which is different from that of central laboratory testing. This poses an additional pressure on billing system to assign different code for these test. This again contribute to the source of error in billing in hands of untrained or newly appointed staff resulting into failure to input the data into data management system due to mismatched test code.

See also

• Rapid diagnostic test

Very Important

References

• Point of Care Testing, a book by Viroj Wiwanitkit