Define point of care testing and list its advantages in the pediatric setting.
Describe the limitations to point of care testing.
Define CLIA-waived testing.
List important considerations when implementing POCT.
List laboratory tests commonly used in critical care.
Describe two challenges associated with laboratory testing and the critically ill patient.
Point of care testing (POCT), as the name describes, is testing that can be done at the point of care. It is also referred to as near-patient testing, or bedside testing. POCT is performed outside of the central laboratory, on small portable devices. There is a significant breadth of technology in POCT, and the field is growing rapidly. Types of technology commonly used in POCT include immunoassay, chemical/enzymatic reactions, electrochemistry, and optical techniques. In general, POCT can be divided into three more or less distinct categories: 1) qualitative, single-use rapid tests, 2) semi-quantitative or quantitative single use cartridges with reader devices, and 3) quantitative multi-use cartridge or benchtop devices.1 Advantages to POCT include reduced turnaround time (TAT) and sample volume requirement as many POCT devices use small sample volumes. These advantages make POCT particularly useful in pediatric critical care settings. However, there are challenges associated with POCT including inaccuracies and interferences, and poor correlation between POCT devices and the main laboratory analyzers. Co-ordination of POCT programs requires attention to quality control/quality assurance, proficiency testing, validation, cost-benefit analysis, and evidence-based practice.
This chapter will cover all aspects of POCT, focusing on its use in the pediatric environment and especially on POCT use in Critical Care situations.
Benefits of Point of Care Testing
Benefits of point of care testing include its ease of use, reduced total turnaround time (TTAT), and small sample volume requirement. The TTAT is the time from when the caregiver orders a laboratory test to the time the caregiver acts on the result of the laboratory test. This includes the time to collect supplies, draw, transport, process, and test the specimen as well as the time to review results in the laboratory (see Figure 11-1). In the critical care environment, POCT devices can simplify the process of obtaining lab values at the point of blood collection. It has been described that much less nursing time is involved in POCT versus sending samples to a central laboratory.2 For example, the steps involved in sending a sample to the central laboratory include ordering the test, drawing and transporting the sample, central lab processing, testing, and reporting, and finally retrieval of the results. When a POCT device is used, the steps can be reduced considerably (Figure 11-1). Policies in the central lab for calling critical value results back to a healthcare provider can add to the TTAT significantly. Turnaround time for critical value call back, in one study, was over ...