I was given one night to create this presentation. I gave this talk to one of our nuclear medicine doctors and a resident (doctor) during his nuclear medicine training session. Since then I have groomed it and and added a few points from the medical microbiology course I was on. Points of interest: The simplest + fastest test in our department. Test with the lowest radiation dose.
The bacteria was first isolated in 1982 by Australian doctors: Barry Marshall + Robin Warren. Only found in humans. Blaser (2005) states research indicates the bacteria has been present in humans for 11,000 years.
Blaser (2005) states even a short treatments of antibiotics, for any reason, will eradicate the bacteria in some people.
Q: Why wait for a month? A: To give any bacteria still present a chance to re-grow.
Q: What is NH4? A: Ammonium.
Q: Why so LITTLE water? A: We want the capsule to settle on the stomach surface NOT float in excess water. Q: Why 2 drinks of water? A: To assure the capsule gets to the stomach.
C14 urea breath test
14 C-Breath Test R. Miner <ul><li>This lecture will discuss the 14 C-Urea Breath test. </li></ul><ul><li>By the end of the talk you will know: </li></ul><ul><ul><li>indications for the test </li></ul></ul><ul><ul><li>patient preparation and contradictions </li></ul></ul><ul><ul><li>how the test is administered </li></ul></ul><ul><ul><li>lab work required </li></ul></ul>
14 C-Urea Breath Test R. Miner 14 C is used to assess the effectiveness of treatment for Helicobacter pylori (H. pylori). H. pylori is a Gram-negative bacteria associated with: - peptic ulcers - gastritis
14 C-Urea Breath Test R. Miner 14 C is produced by: 14 N(n,p) 14 C 14 C decays to 14 N, giving off a - The - energy is 160 keV max (49) keV mean 14 C half life is 5730 years
14 C-Urea Breath Test R. Miner The infection rates of H. pylori is: Up to to 80% of the adult population in Puerto Rico. Almost 50% in adults in North America over 50 yrs old. Only 10% to 20% of the people who have H. pylori develop peptic ulcers. The bacteria is spread by: - mouth/mouth - fecal/mouth
14 C-Urea Breath Test R. Miner <ul><li>H. pylori is associated with peptic ulcers and gastritis. </li></ul><ul><li>The best method of ulcer treatment is a combination of: </li></ul><ul><ul><li>Antibiotics (e.g.: metronidazole, tetracycline) </li></ul></ul><ul><ul><li>Proton pump inhibitors (Prilosec, Prevacid…) </li></ul></ul><ul><ul><li>Bismuth subsalicylate (Pepto-Bismol) </li></ul></ul><ul><li>The above treatment results less than 5 to 10 % </li></ul><ul><li>re-occurrence in 1 year. In contrast, without the above combined treatment the recurrence over 1 year is </li></ul><ul><li>80 to 100%. </li></ul>
14 C-Urea Breath Test R. Miner The primary indication for this test is the verification of treatment for the eradication of H.pylori. bacteria. This verification can be done one month after treatment. Serology tests can remain positive for 6 - 12 months. The 14 C test can give results one month after the completion of treatment. This means: blood work can detect the problem while the 14 C test can indicate if therapy was successful. The 14 C test has: A sensitivity (true positive) of 90 to 100 % A specificity (true negative) of 78 to 100 %
14 C-Urea Breath Test R. Miner Contraindications: Still on ulcer treatments. Patient preparation: NPO for 6 hours. Off medications for 4 weeks (antibiotics, proton pump inhibitors, bismuth).
14 C-Urea Breath Test R. Miner The 14 C-urea tablet is metabolized by H.pylori producing CO 2 and NH 4 . The 14 CO 2 is absorbed by the blood system and exhaled by the lungs. The exhaled radioactive 14 CO 2 can be collected and measured.
14 C-Urea Breath Test R. Miner Protocol summary: 1) Patient swallows a 37kBq 14 C-urea capsule with 20 ml of water. 2) 3 minutes later 20 ml more of water consumed. 3) 10 minutes after step ‘2)’ a standard balloon is inflated by the patient.
14 C-Urea Breath Test R. Miner Processing summary: The volume of the balloon is drawn out into a trapping solution to capture the CO 2 . A scintillation cocktail is added to the vial. The vial is place in a scintillation counter.
14 C-Urea Breath Test R. Miner The 14 C beta particles cause scintillations in the solution. Evaluation of results for a 10 minute period: < 50 cpm indicates NO H.pylori is present. 50 - 199 cpm is inconclusive. 200+ cpm indicates H.pylori IS present. False negatives (no H.pylori present) can be caused by: Not off indicated medications long enough. Not NPO long enough. False positive (H.pylori present) can be caused by: Gastric surgery.
14 C-Urea Breath Test R. Miner Dose to patient is 0.003 mSV. (Equivalent to ~1 day of background radiation) Critical organ: Bladder wall. Mode of elimination: Exhaling and urination. Physical half life of 14 C is 5730 years. Biological half life of 14 C is 40 days.
Summary R. Miner The 14 C- Urea breath test is an accurate method to assess the effectiveness of treatment for gastric ulcers and H. pylori.
References R. Miner Blaser, M., (2005). An endangered species in the stomach . Scientific America, February 2005 Ingraham, J., Ingraham, C., (2004) Introduction to microbiology. (3 rd ed.) Belmont, CA: Brooks/Cole Kumar, V., Cotran, R., Robins, S., (2003) Basic Pathology. (7 th ed.) Philadelphia, PA: Saunders Page, C., Curtis, M., Hoffman, B., Sutter, M., Walker, M., (2002). Integrated Pharmacology. Toronto: Mosby SNM (2001). Procedure Guide for C-14 Urea Breath Test. Version 3.0 The Ottawa Hospital. (2004) C-14 Breath Testing for H. Pylori. Nuc13 (01/2004) and PYtest Information Sheet Taylor, A., Schuster, D., Alazaki, N. (2006). A Clinician ’s Guide to Nuclear Medicine. (2 nd ed.) SNM: Reston, VA Wilson M. (1998). Textbook of Nuclear Medicine. Philadelphia: Lippencott-Raven Ziessman, A. Harvey, O ’Malley, P. Janis, Thrall, H. James (2006) The Requisites of Nuclear Medicine (3 rd ed.) Philadelphia, PA: Elsevier Mosby