Pieces of the POCT puzzle Point-of-care testing: changing the way patient care is delivered

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LEARNING OBJECTIVES

Upon completion of this article, the
reader will be able to:

1. Identify the goal(s) of POCT.
2. List sites where POCT is performed.
3. Name the POC Tests available to the healthcare field.
4. Explain the purpose of the POCT needs assessment.
5. State the evaluation criteria used to select POCT devices.
6. Explain how the use of POCT can lower economic costs.

Point-of-care
testing (POCT) is defined as testing at or near the site of patient
care.^1,2 The goal of POCT is to facilitate rapid diagnosis
and faster treatment decisions to improve patient care and reduce
morbidity and mortality.¹ POCT impacts every branch of the
healthcare system, including hospitals, outpatients, and disaster and
emergency situations. The ability of POCT to be utilized in all these
respective locations has demonstrated the significant potential POCT has
to positively impact and change the way healthcare is delivered to the
patient population — ultimately, with the goal of improving patient care
— wherever that may be.

POCT device design is a critical aspect for efficient POCT device performance.

While the beneficial use of POCT in the hospital and
outpatient settings primed the transition of using POCT in emergency and
disaster situations, the 2004 tsunami in Southeast Asia and Hurricane
Katrina in the United States in 2005 exposed the lack of disaster medical
preparedness worldwide.^1,2 The POCT was extensive and the
disaster response immense, but results showed it was inadequate.¹
Compromised hospitals, roads, and communications hindered rescue efforts by
first responders who carry POCT devices such as oxygen-saturation monitors
(pulse oximeters), blood-glucose meters, and other small hand-held devices.^1,2
Furthermore, POCT instruments failed to effectively operate under the
adverse environmental conditions of these respective disaster situations.²
Regional catastrophes like these “newdemics”^3,4 lead to
sequential magnified setbacks and, typically, communities lack the POCT
resources to effectively handle the respective disaster situations.^1,2
These disasters not only highlighted the significant potential for POCT to
positively impact disaster response and patient outcomes but also displayed
the need for new sturdy, hand-held, and robust POC technologies capable of
effectively operating in disaster situations. In the future, the versatile
use of POCT will positively impact and change the way patient care is
handled by doctors, medical personnel, and disaster and emergency
responders.

What POC tests are available?

The use of POCT has become standard in nearly
every sector of the healthcare field. The ability of POCT to be
performed at the bedside of the patient to facilitate rapid diagnosis is
efficacious to the patients, doctors, medical personnel, and laboratory
technicians in saving valuable time from diagnosis to treatment.^1,2
Table 1 displays where POCT is used, including hospitals, outpatient
sites, and disaster and emergency sites. The use of POCT at the site of
patient care has primed the transition from not only using POCT in
hospitals and for outpatients but also at disaster and emergency sites.

A variety of POC tests are available, including both
in vitro and in vivo, which are utilized by hospitals,
outpatients, and disaster sites. Many POCT in vitro instruments
measure hematocrit using electrical conductance sensor (ECS), co-oximetry,
or various other methods.¹ O₂ saturation can typically
be measured utilizing fiber optics for multiple wavelength measurement.¹
The use of sensors for in vitro testing allows simultaneous
measurement of several analytes quickly and effectively to facilitate
evidence-based decisions for patients.¹ In vivo POCT
devices for monitoring blood chemistry are typically limited and include
analytes that vary rapidly, require fast response, or need frequent
measurements.¹ These analytes primarily include oxygen
saturation, blood glucose, blood gasses (PO₂ and PCO₂),
pH, potassium, sodium, ionized calcium, hematocrit, and — to a lesser extent
— urea, creatinine, and lactate.¹ The focus of development for
these POCT devices has been for use in the hospital and intensive-care
units.^6,7 Blood-glucose monitoring continues to be an area of
interest for ongoing POCT-device development, especially for outpatients
with diabetes who require monitoring on a regular basis. Development has
been focusing on wearable or implantable blood-glucose devices to allow for
efficient outpatient monitoring and management of diabetes to improve
long-term patient care.¹ POCT development for various disaster
sites and emergency situations has focused on developing pathogen-detection
test clusters.⁸ These pathogen test clusters can be tailored to a
respective disaster or emergency situation to test for prevalent pathogens
in these respective situations. In order to develop the most effective and
efficient POCT device, however, certain criteria must be considered,
especially for POCT use in disaster and emergency situations.

POCT and needs assessment

POCT serves as a critical component of for
hospital care, outpatient services, acute disaster response, and
follow-up recovery; but, at present, POCT devices available in the
consumer market and for routine use do not meet adequate standards for
disaster conditions.⁸
During a disaster, emergency medical responders utilize the POCT to
rapidly diagnose and treat victims.⁹ The specific pathogens
present at a disaster site vary, however. To effectively facilitate the
treatment of victims, emergency medical responders need POCT devices
with specific-pathogen test clusters tailored to a respective disaster
site.⁸
In order for POCT devices to be effective at facilitating
evidenced-based medical decisions and improve patient outcomes, they
need to be tailored to test for specific pathogens that have been shown
to be present in a specific disaster scenario.

In an effort to close the gaps between current POCT
technology and availability, a national needs-assessment survey that
specifically focuses on pathogen detection and development of devices
capable of withstanding harsh disaster conditions is currently being
conducted. Clinical needs assessment serves as a tool for gathering
information on POC devices, test clusters, and pathogens considered critical
for diagnosis at a specific disaster site.⁸ The clinical
needs-assessment survey utilizes “visual logistics” to specifically focus on
what pathogens clinicians want to test for in a particular disaster
scenario.⁸ By surveying experts in the field of disasters and
emergencies, what is considered a priority and beneficial to POCT is clearly
evident. The POCT Center at the University of California-Davis/Lawrence
Livermore National Laboratory (LLNL), one of four National Institute of
Biomedical Imaging and Bioengineering (NIBIB) POCT research centers,
specifically focusing on infectious-disease detection would like to extend
an invitation to all MLO readers to participate in our clinical
needs-assessment survey; please see Table 2 for instructions.⁹
Through clinical needs assessment, the development of pathogen-detection
test clusters and devices capable of giving rapid and reliable diagnosis
will enable better patient care at a disaster site.

POCT selection and evaluation

POCT devices must meet specific standards,
especially if the POCT instrument will be deployed to disaster and
emergency sites that harbor harsh environmental conditions. The system
performance of the POCT device must be considered. Results from POCT
devices must be accurate, reproducible, stable, comparable, and fast.¹
Additionally, the performance of the POCT device should not be
compromised if environmental extremes are encountered. In a recent study
conducted by Dr. Louie and colleagues, results indicated that glucose
test strips and blood-gas cartridges may not be able to withstand harsh
environmental conditions often encountered at disaster sites.¹⁰
Thermal stresses adversely and inconsistently affected the performance
of glucose-meter test strips and blood-gas analyzer cartridges.¹⁰
Without durable and robust POCT equipment, diagnosis and treatment of
victims at disaster sites becomes increasingly complicated and hindered.
In order to effectively and efficiently treat patients, current POCT
technologies and devices must be improved and refined to meet not only
hospital and outpatient conditions, but also those encountered in
extreme disaster and emergency conditions.

POCT device design is a critical aspect for efficient
POCT device performance. POCT instruments must be compact, durable,
lightweight, portable, power efficient, robust, and hand-held.^1,10
POCT is specifically designed to be utilized at or near the patient and
must, therefore, be deployable to any site the patient might be located,
including disaster sites.¹⁰ Not only must the POCT device be able
to operate in a hospital or outpatient locations, but also at disaster and
emergency sites, where conventional amenities will not be present.

New POCT devices must meet current requirements for
accreditation agencies, whether state, federal, or voluntary, and have
simplified protocols for educating potential operators.¹ POCT
devices held to the same standards present for hospitals ensures better
patient care. Additionally, POCT devices must be accurate and the results
comparable to established standards. During disaster situations, competent
POCT operators are critical to facilitating efficient testing needed for
rapid diagnosis and treatment. POCT devices supplemented with educational
resources to achieve minimal operator training for effective device
operation enable efficient patient care.¹