6th week of attachment

Hi this is my 2nd post here. Sorry for the delay in my posting. I was supposed to post yesterday. Anyway, I am permanently stationed at Biochemistry/Immunology Section for these 5 months.

Subject Title: Clinical Chemistry

Name of Test: Urea Breath Test

WHAT IS UREA BREATH TEST?

The urea breath test (UBT) is a test for diagnosing the presence of a bacterium, Helicobacter pylori (H. pylori) in the stomach. H. pylori causes inflammation, ulcers, and atrophy of the stomach. The test also may be used to demonstrate that H. pylori have been eliminated by treatment with antibiotics.

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PRINCIPLE

The patients are given urea labelled with 14C or 13C orally. In the presence of H. pylori organism, urea is converted by the bacterial enzyme urease to 13CO2 and ammonia. The 13CO2 is absorbed in the bloodstream and gets transported to the lungs exhalation in the breath. This results in an increase in the ratio of 13CO2 to 12CO2 in expired breath in the Post-Dose breath sample. In the absence of H. pylori, the Post-Dose breath sample has essentially the same amount of 13CO2 as the baseline breath. The exhaled CO2 is trapped, processed and analysed. 14C is a beta emitting radioisotope and can be detected using liquid scintillation counting and 13C is a stable, non-radioactive isotope that is measured using a mass spectrometer (infrared spectroscopy). The difference in the 13CO2 levels are calculated too.

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MATERIALS needed (For 1 patient)

1. Two breath bags
2. One Urea tablet
3. UBiT- IR300 Machine
4. 100ml of water
5. Disposable Cup(s)
6. Timer

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METHOD

[Patient’s Preparation before Test]
a) The patient must fast without drink or food for at least 6 hours before test
b) If the patient is a smoker, he/she must not smoke 2 hours prior to test
c) The patient must stop all antibiotics/antibacterial drugs at least 4 weeks before test [e.g. Amoxicillin (Amoxil, Moxam),Bismuth tricitrate (Denol), Clarithromycin (Klacid), Fasigyn (Trinidazole), Metronidazole (Flagyl), Tetracycline (Tetrex, Mysteclin, Achromycin), and any other antibiotics]
d) The patient must stop all Proton Pump Inhibitors at least 1 week before test [e.g. Losec (Omeprazole), Somac (Pantoprazole Sodium Sesquihydrate), Zoton (Lansoprazole) and Nexiam]
e) Lastly, the patient must stop all H2 Receptor Antagonists at least 1 day before test [e.g. Cimetidine (Tagamet, Sigmetadine, Magicul), Famotidine (Amfarnax, Pepcid, Pepcidine), Nizatidine (Tazac) and Quick EzeRanitidine (Zantac, Rani 2)]


[Patient: Steps DURING the test]
a) Breathe into “Pre-dose” or “Baseline” blue breath bag WITHOUT taking the urea tablet
b) Within 5 seconds, swallow the UbiT tablet (under fasting condition) with 100ml of water. The tablet must not be chewed, crushed or dissolved.
c) Lie down on your left side for about 5 minutes (to allow the tablets to react more with H. pylori)
d) Remain seated for another 15 minutes (to enable CO2 gas from being exhaled from lungs properly)
e) Breathe into “Post-dose” or “Sample” bag

These 2 bags with the Laboratory Request Form will be sent to the Clinical Laboratory for analysis.

[Medical Technologist: Procedures in the Laboratory]
a) Register the sample at administration section
b) Passed on to Biochemistry section
c) Check the labels and paste the labels onto the bags if not pasted yet
d) Conduct test using the machine UBIT-IR300
e) To use the machine:
1. Press “Yes”
2. Enter Sample ID/ Patient’s Lab Request Number
3. Press “ENTER”
4. Press “Yes” to run/start
5. Insert “Baseline” bag at Pre knob
6. Insert “Sample” bag at Post knob
f) Verify results

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RESULTS AND INTERPRETATION

A value of 2.5% or higher indicates that the patient is positive for H. pylori infection. If the isotope is detected in the breath, it means that H. pylori is present in the stomach. If the isotope is not found, H. pylori is not present. When the H. pylori is effectively removed by antibiotics, the test changes from positive (isotope present) to negative (isotope absent).


P.S. I have a picture of the machine but somehow something seem to be different at blogger.com. I can't seem to bold my words too and suddenly, there is no usual icons for me to press in order to attach files or pictures ): Anyway, you can just go to this link shown below:

http://www.gribbles.com.my/ubt2.html

Signing off,
Rebecca Chew (0703363B)
God bless (: