How are INR blood tests performed?
For the most part, INR testing takes place at the hospital or doctor’s surgery. The test involves withdrawing blood, usually from a vein in the arm. This blood sample is then sent to a laboratory to be analysed. The results of the test will be sent back to the doctor, who can then contact his patient to discuss any action required.
Less commonly, your nurse or doctor may use a portable device to carry out inr testing on the spot. This is known as ‘point of care’ testing. It requires only a drop of blood, which is taken from a finger prick, and the device is usually able to present the results in a matter of minutes.
On rare occasions, a patient may be provided with a portable device to allow them to conduct the INR test at home. This option, known as self-monitoring, requires the patient to undergo thorough training and the test must be performed exactly as the doctor advises. After performing the self-check the patient calls in the results to their doctor to discuss dosage.
Using a portable device for ‘point of care’ testing or self-monitoring has a number of disadvantages. Most importantly, results are not as accurate or consistent as a full laboratory test. Moreover, the portable devices require to be calibrated on a regular basis to ensure that the readings given are similar to a standard INR test. The user also requires to undergo extensive training to ensure a sufficient level of accuracy is achieved when testing.
I recently attended the Eye Dept at Worcester Royal Hospital for a Cataract and I-Stent procedure.
The day previously I had undergone a venous Blood Test at the Pricess of Wales Hospital in Bromsgrove which was sent for Lab testing.
On arrival at the Hospital for my procedure the nurse dealing with me refused to check the Lab Test and insisted on conducting a Finger Prick Test. This red 3.3 and was outside the prescribed acceptable range. Had she checked the result from the venous sample it was 2.8.
The end result was that her reading was accepted, no second reading was conducted and my procedure therefore was cancelled.