What you need to know about Urea Breath Test
Jane is again on duty at the Medical Ward. She is now on her last year in nursing school and is determined to learn everything that she can in preparation for the board exam as well to help her gear up to become a quality nurse someday. She is making her rounds together with her classmates and Clinical Instructor when a patient calls her attention.
“Sorry to bother you, nurse. But I would just like to ask something. I am scheduled for an exam tomorrow and I don’t really understand it,” says the patient.
“Okay, ma’am. What exam are you exactly referring to?” asks Jane.
“The doctor said I will be undergoing Urea Breath Test. What is that? Can you enlighten me a bit?”
Confused, Jane excuses herself to ask her Clinical Instructor who she believes is more knowledgeable on the subject than she is. All she knows is that it is an exam for patients with ulcer. She isn’t exactly sure what happens during the test.
As she approaches her C.I., she tells herself to read more about the test later so that the next time a patient asks her, she will have a decent answer to give.
UBT: An overview
The urea breath test or UBT is a test that diagnoses the presence of a bacterium, Helicobacter pylori (H. pylori) in the stomach, which causes inflammation, ulcers, and atrophy of the stomach. It may also be used to demonstrate that H. pylori has been eliminated by treatment with antibiotics.
Helicobacter Pylori in the stomach produces urease. The urea breath test is based on the ability of H. pylori to break down urea, a chemical made up of nitrogen and carbon, into carbon dioxide which then is absorbed from the stomach and eliminated in the breath. The urea normally is produced by the body from excess (“waste”) nitrogen and then eliminated in the urine.
Prior to the test, the following should be followed in order to allow the test to work properly:
- The physician must be informed if the patient is pregnant, has a lung or heart condition or any other disease, or if he/she is allergic to any medications.
- Nothing to eat or drink for 3 hours before the test. (NPO)
- Any form of antibiotic have to be ceased at least 4 weeks ago. Proton pump inhibitors such as Nexium, Pariet, Losec and Somac to be ceased at least 1 week prior to the test.
- Certain medications may be taken only if approved by the doctor the day of the procedure and should be taken with only a small sip of water if it is within four hours of the procedure.
- Medications must not be discontinued without first consulting with the primary or referring doctor.
- The patient may be advised for re-testing four weeks after completing therapy to determine its success.
What happens during this test?
During this test, the patient will be asked to swallow a capsule containing urea made from an isotope of carbon, and after 30 minutes, a breath sample is collected in some sealed test tubes. Isotopes of carbon occur in minuscule amounts in nature, and can be measured with special testing machines.
If H. pylori is present in the stomach, the urea is broken up and turned into carbon dioxide. Then, the carbon dioxide is absorbed across the lining of the stomach and into the blood. It then travels in the blood to the lungs where it is excreted in the breath. Samples of exhaled breath are collected, and the isotopic carbon in the exhaled carbon dioxide is measured.
The breath in the test tubes is later tested in the laboratory.
If the isotope is detected in the breath, it means that H. pylori is present in the stomach. On the other hand, if the isotope is not found, H. pylori is not present. And when the H. pylori is effectively treated by antibiotics, the test changes from positive (isotope present) to negative (isotope absent).