Point of care testing ( POCT)

This slide holds the explanation and ideas regarding the intricacies of POCT

4. Introduction
Point-of-caretesting(POCT)isdefinedasmedicaltestingator
nearthesiteofpatientcarei.e,pointofcare.
AccordingtoCollegeofAmericanPathologists(CAP).
“Diagnostictestsdesignedtobeusedatornearthesitewherethe
patientislocated,thatdonotrequirepermanentdedicatedspace,
andthatareperformedoutsidethephysicalfacilitiesoftheclinical
laboratories”

5. •First reported : papyrus documents 1550 B.C.,
•Egyptian physicians using ants to determine glycosuria in patients
suspected of having diabetes mellitus.

6. Nearpatienttesting,bedsidetesting,ancillarytesting,
alternativetestinganddecentralizedtesting

7. Widely used ASSURED criteria for rapid tests by WHO:
•A = affordable
•S = sensitive
•S = specific
•U = user friendly -simple to perform
•R = robust and rapid (results available in less than 30
minutes)
•E = equipment free
•D = deliverable to those who need the test

8. •Improvequalityofpatientcare
•Enhanceefficiencyofpatientcare
•Increasephysicianandpatientsatisfaction
•Improvepatienteducation
•Decreaseliabilityrisk
•Minimizeburdenatcentrallevel

9. POCTdevicessmallamountsofunprocessedspecimen,
useoffingersticksovertheriskofphlebotomy.
blood gas, electrolytes, pregnancy, cardiac, and infectious
disease testing.
convenience of POCT has led to broad adoption of POCT
Small enough to be portable , enhancing the possibility of
“ bringing lab to the patient.”
Current estimates POCT encompasses nearly one third
of the in vitro diagnostic testing
Contd…..

10. Advantages
Reduced turn around time
Improved patient morbidity & mortality
Reduction in hospital admission
Improved interaction between patient
and carer
Reduction in clinical visits
Improved cost of care
Reduction in administrative work associated
With test requesting & reporting

14. Staff Requirement
•Basically anyone can perform POCT with proper training and
documentation of competency
•Physicians, nurses, aides, phlebotomists, technicians and
technologists
•Getting all staff to perform POCT every time the same way that the
test is conducted is logistical challenge.
•Laboratory professional resource of technical information and
can assist in POCT program .

15. Ideal requirements
•First result in a minute or less
•Portable instruments with consumable reagents catridges
•Single-operating protocol
•Capability of direct specimen analysis( whole blood, CSF, urine) / non
processed sample
•Simple operating procedure
•Flexible test menus

16. •Resultthatmeettheanalyticalspecificationthatare“fit-for-
purpose,”andwithaccuracyandprecisioncomparablewiththose
ofcentralLab.
•Built-in/integratedcalibrationandqualitycontrol
•Ambienttemperaturestorageforreagents
•Lowinstrumentcost
•Built-inregulatoryrecordkeeping
•Resultprovidedashardcopy,storedandavailablefor
transmission.

17. Individual components of POCT devices
barcodeidentificationsystems
sampledeliverydevices
reactioncell
sensors
controlandcommunicationssystems
datamanagementandstorage
manufacturingrequirements

18. (5) Sensors
•types of sensor technology used in POCT instruments
Optical or
electrical
signal
chemosensors Biosensor

20. Types of POCT devices

21. POCT devices
1.Single-usequalitativestriporcartridgeand/orstripdevices:
Awiderangeofdevices,includingsingle-padurinetest(
dipsticks),complexstripandimmunosensors.
•Dipsticks=singlepaddevices,simpleinconstruction,composedof
padofporousmaterials,suchascellulose,thatisimpregnatedwith
reagentandthendried.Readvisually
•Complexstrips=complexpadwithseverallayers,semipermeable
membrane,needtimeforcompletionofreaction
•Immunosensors=arebiologicalsensorswithrecognitionagentan
antibodythatbindstoananalyte.

22. Lateral flow immunoassay for troponinT

23. Single-use quantitative cartridge and strip test
with monitoring devices
•Differenttheyincludemeterormonitoringdevices,there
byenablingthemfordetectionandquantificationofanalytes.
•Themajorityofthedevicesincludedinthiscategoryareused
tomeasureglucose.

24. Electrochemical glucose strip
•Thick–filmtechnology,
severallayerhaving
specificfunction.
•Bothwaterandglucose
mustpassintothefilm
oranalyticallayer
•The relation between
reflectance and the
glucose concentration is
given.
C=analyteconcentration.
K=absorptioncoefficient
S=scatteringcoefficient
R=percentofreflcetance

25. POCT for anticoagulant therapy
•Optical detection technique.
•pumping technology , which pumps the sample
backward and forward through narrow aperture
•Optical sensors monitors the speed at which the
samples move and as the clot is formed, the speed
decreases , when predetermined level is reached
time is recorded.

26. Blood gas analyzer
•is a microprocessor-controlled medical instrument measuring optical
fluorescence from discrete sensors called optical electrodes
(optodes).
•A disposable, single-use cassette contains all of the elements needed
for calibration, sample measurement and waste containment.
•The analyzer warms the cassette to 37.0 ±0.1 °C (98.6 ±0.1 °F)
•When calibration is verified, the analyzer aspirates the blood sample
into the cassette and across the optodesensors
•Fluorescence emission is then measured after equilibrating with the
blood sample

27. Multi-Use cartridge and Bench Top systems
•Use for critical care
•In area like ICU, surgical suite and
emergency room.
•Some of them uses thick film sensors or
electrodes in strips to measure glucose,
lactate and urea
•Sensors are reusable
•Also used to measure blood gases and
electrolytes
•Sensors are incorporated with reagents
and calibrators on to single cartridge
placed in small to medium sized portable
care analyzer.
•Each pack Measures certain number of
samples for certain time and replaceable.
Nycocard reader II

28. Non invasive POCT
1)Transcutaneousmeasurementofbilirubin:
Themeterwillsendaquickflashoflightthroughthe
skintomeasurethebilirubinlevel
2)Pulseoximetry:formonitoring patient's
O
2saturation.
The principle ofpulse oximetryis based on the red and
infrared light absorption characteristics of oxygenated
and deoxygenated hemoglobin
3) Glucowatch : uses the principle of iontophoresis. A
replacebleauto sensors sticks to the skinlow electric
currents pulls the glucose through skinglccollected in
two gel collected disc in auto sensors.
Another electrode in autosensorsmeasures the glucose.

29. RISK OF POCT
•can act as infectious reservoirs for nosocomial and antibiotic-resistant
organisms
•blood glucose testing devices have been linked to transmission of hepatitis
B infection among patients
•Although may seem simple, these devices are not innocuous.
•Consumers and operators of these devices need to be aware of the
potential risks and take steps to ensure appropriate test quality

30. POCT AND ENVIRONMENT
Unlikecorelab,POCToccursinvariousconditionandsetting
ReagentofPOCTsensitivetoheat,lightandmoisture
Reagentshouldn’tbefreezeoroverheated.ExPregnancyKit
proteinAbgetdenaturesathighandlowtemp.
Urinedipsticksandoccultbloodtestdevicechemicaldegraded
atmorelight,heatandhumidity.Soshouldbekeptindry
cabinets,awayfromsourceofmoisture.
Testorkitsleftattrunkofcarandbackofanambulancecan
freezeinwinterandcookinsummer.
Bloodgasdevicecalibratedatsealevels.PerformanceofPOCTat
higherlevels,Helicoptersorpressurizedaircabinmayaffect.

31. Future of POCT
•Example:Glucose-sensingcontactlensinvented

32. ANY QUESTION ?????