Norm of Breath Hydrogen Analysis
<20 ppm elevation over fasting level.
Usage of Breath Hydrogen Analysis
Assessment of orocecal transit time; determination of bronchiectasis, irritable bowel syndrome, lactose intolerance, hypolactasia; screening for early diagnosis of necrotizing enterocolitis; and evaluation of peptic ulcer disease before and during treatment with ranitidine.
Description of Breath Hydrogen Analysis
This test measures the hydrogen exhaled at specific intervals during the first 3 hours after ingestion of the carbohydrate (such as lactose, lactulose, fructose, or sucrose) being studied. In the normal client, hydrogen is produced exclusively by the bacterial metabolism of carbohydrates. Clients who are unable to digest or absorb carbohydrates in the small intestine have an increased volume of carbohydrates reaching the colon. These carbohydrates are metabolized in the colon, producing hydrogen, which is absorbed in the colon and exhaled by the lungs. The hydrogen breath test detects higher than normal levels and abnormal timing of peak releases of exhaled hydrogen. Ranitidine inhibits the action of histamine on the H2-receptors of the parietal cells of the stomach, thus reducing hydrochloric acid production. The breath test can be used to evaluate hydrogen release after administration of the ranitidine.
Professional Considerations of Breath Hydrogen Analysis
Consent form NOT required.
- See Client and Family Teaching.
- Obtain a syringe or balloon.
- After measurement of a basal breath hydrogen level, an oral dose of lactose, 1 g/kg of body weight, is given.
- End-alveolar air is expired into a 30-mL glass syringe or a special plastic balloon.
- The breath sample is injected into an analyzer to determine H2 and Co2 concentrations.
- A rise of 720 ppm in exhaled hydrogen is diagnostic for lactose malabsorption.
- Clients with bacterial overgrowth of the small intestine will have an increased production of hydrogen, with an early peak (within 3 hours) of hydrogen release after carbohydrate ingestion.
- Clients with disease of the small intestine and carbohydrate malabsorption have a later peak of hydrogen release.
- Resume normal diet.
Client and Family Teaching
- Fast after midnight the day of the test. A carbohydrate-controlled diet the day before the test affects the fasting breath hydrogen levels and may improve the test accuracy.
- Do not use laxatives or enemas for 3 days before being tested.
- Do not smoke for at least 15 minutes before being tested.
Factors That Affect Results
- Diarrhea within 3 days before the test invalidates the results.
- Storage of the samples allows for leakage of the gases. A glass syringe stored on its side with the barrel lubricated with mineral oil will have negligible leakage over a 2-week period. Upright storage may result in leakage of mineral oil and loss of the barrel seal.
- High-fiber diet increases results.
- Hydrogen content increases as carbohydrate malabsorption increases.