IVD and Point of care testing

Mark Grumbridge – Nursing Advisor, Devices MHRA

What is an in vitro diagnostic medical device (IVD)?

Broadly, a device is an IVD when the manufacturer has intended its use for the in vitro diagnostic examination of specimens derived from the human body. IVDs can include:

What is an in vitro diagnostic medical device (IVD)?

• blood glucose meters, pregnancy tests, test kits used in hospital laboratories

• reagents, calibrators and control materials, whether supplied alone or as part of a kit

• analyser systems, analytical instruments,

apparatus or equipment

What is POC testing?

Testing, using an IVD device, that is performed near or at the site of a patient with the result leading to a possible change in the care of a patient. Examples of these include: • Blood glucose testing• Pregnancy testing• Blood gas testing• Urinalysis testing

Does not cover home/self testing or laboratory based testing.

Typical POCT devices

Blood Glucose meters

Glucometers – The Science

• The science behind these modern blood glucose meters is to draw in a set amount of blood.

• Often it is 1 microliter (a millionth of a liter). • The glucose in the blood reacts with an enzyme called

glucose oxidase that pulls 2 hydrogen atoms off of the glucose molecule.

• A third chemical pulls the 2 hydrogen atoms off of the glucose oxidase enzyme.

• The third chemical then has those 2 hydrogen atoms removed by the use of an electrical current.

• By measuring how much electrical current it requires to remove these hydrogen atoms, the number of glucose molecules can be calculated

Plasma / Whole blood testing

• Capillary blood used for test strips

• Lab testing uses plasma

• Some test strips are calibrated to give results comparable with lab testing (av 12% higher than whole blood)

Choice of equipment - considerations

• Suitable to be used in the intended setting ?• Is it single use or can it be used on multiple

patients ?• Is the device CE marked ?

Units of measurement

• UK units of measurement are mmol/l

• Other countries use mg/dl

• Ensure the device is set to mmol/l

Training should include…….

• Basic principles of measurement

• Health & safety• Calibration and QC

checks• Trouble shooting• Patient management • Competency

SOPStandard operating procedure

• MUST be in place wherever BG testing is undertaken

• Includes the manufacturers instruction

• Use in conjunction with local policy / procedure / guideline

Quality control

• Calibration for each new pack of test strips

• Internal and external quality assessment

Consumables

• Consumables such as test strips, lancets etc must be compatible with the device

Management of results

• Ensure accurate recording, maybe paper recording or electronic

• Ensure staff act appropriately with any abnormal result

Incident reporting

• Report locally by following internal policy (DATIX)

• Direct to MHRA• Direct to the manufacturer• Quarantine affected devices and equipment if

necessary• Ensure alternatives are available if the

product(s) are recalled

Further sources of information

• Management and use of IVD point of care test devices - December 2013

• Blood glucose meters booklet• POCT Top ten tips• Management of IVD medical devices

• All available at www.mhra.gov.uk/safetyinformation