Friday, 26 October 2007

Time to clear all queries...... for cholesterol measurement!

Cheng Hong said:
Is there any other test that is done together with this test to confirm the results in case there is interferance due to bilirubin?

I say:
Pls note that a bilirubin of up to 20mg/dL do not interfere with the result. Anyway a single cholesterol measurement does not truly reflect a person's usual cholesterol concentration, it is highly recommended to perform the test twice on 2 separate occasions. The best is to encourage the participant to go to our Hospital Clinic for a thorough Liver Function check up (if the result seems weird) before a clinical diagnosis is finalised. Frankly speaking, we're trying to promote our health screen packages at the outreach program too.

Elaine said:
As you said, you went for outreach programme and did this cholesteral measurement. If the participant have the habit of eating vit. C pills everyday(is it the same as IV infusion?), does it means that he/she cannot do this test?

I say:
Since vitamin C pills are water soluble, they are flushed out of our immune system on a daily basis and do not have any significant impact on the measurement unless there is an over dosage jus before the test or having an IV infusion concurrently. This would then caused a falsely low cholesterol level.

Jue Xiu said:
hihiI just wonder as u mention the test will be affected by the 1.)IV infusion of Vitamin C2.)Elevated bilirubin (>171umol/L); Jaundice3.)Haematocrit > 55%4.)Methylaminoantiprine5.)Gentisic AcidWouldnt there be any discrepancy regarding the result? Or this test is specific for certain people due to the limitation?

I say:
helloo... I would say no, its not specific since it is used for point-of-care testing. However i would say yes for result discrepancy based on the degree of interference caused by what i've mentioned. Actually all tests have their limitations, so it's better for the particpants to have their blood serum tested too - sell health packages!

Vino said:
hey hey U mentioned abt detection reagent present in the yellow region of the test trip. wat is/ are the detection reagent?? that causes the reaction, colour change, to occur?

I say:
Sorry Vino, I could not find answer to your question as i believe the manufacturer is unwilling to reveal their secret reagent recipe. However, in parallel with the detection reagent from another brand, it was revealed that it contains microorganisms esterase and oxidase, 4-aminoantipyrine, horseradish peroxidase & substituted aniline derivatives. The reaction/colour change occurs due to liposis of the triglycerides and then measurement by photometry (refer to below, Cass's Question & my answer)

Charmaine said:
Just want to say, I learnt to use this as well!But I'm not measuring blood cholesterol level, instead I'm measuring blood glucose levels. XDCheers~Charmaine TanTG01

I say:
Oh... we too! We actually perform the finger-prick for the blood cholesterol 1st and squeeze another drop of blood for the glucose measurement as it takes a shorter time for the glucose device. While waiting for the 3 min to be up, I then measure the participant's blood pressure. Usually they would complain that their blood pressure is high due to the shock/fear that they develop for the finger-prick. All excuses.... I find it the same to measure immediately when they were jus made to sit down.

Avery said:
Hi Pei shan,i would to ask how do you select the depth of the Accu-Chek Safe-T-Pro Plus® lancet device?based on the finger thickness(hehe ^_^)?

I say:
Bingo! The lancet is usually set at a moderate depth which is sufficient to prick a person's finger. However if the person has thick skin especially the males, shift it to the deeper profile. So far that day, I only adjusted to the deepest twice, both times for men! It's better to adjust the depth than to be sorry and prick another time.

Cass said:
hi pei shan;)"The meter measures the intensity of the reaction colour based on reflectance photometry and calculates the concentration of the sample through a "lot-specific" algorithm (i.e. the data previously entered by mean of code strip), giving the cholesterol reading."what is reflectance photometry? intensity of the reaction.. meaning the darker the colour the higher the cholesterol level?

I say:
Helloooo... This is a very good question which I've lacked explaining. The reaction principle of Accutrend® Triglycerides is lipolysis of triglycerides to give free glycerol and fatty acids by the activity of a cholesterol esterase. The glycerol is phosphorylated by glycerol kinase, and the resulting glycerol phosphate is oxidized by a glycerol-phosphate oxidase. Molecular oxygen subsequently leads to the formation of hydrogen peroxide, whose oxidation equivalents are transferred by a peroxidase to an indicator, giving a blue-gray oxidation product. The intensity of the color is measured by reflectance photometry(American Association for Clinical Chemistry, Inc.) . The darker the colour, the higher the cholesterol level and the device converts this reading into a result for display.
For further reading, pls refer to

Pei Shan

No comments: