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Test Code LAB2391 Breath Tolerance Carbohydrate Malabsorption

Important Note

This test must be scheduled with the Chemistry Laboratory at 206-987-3860. Outside orders should be faxed to 206-985-3124.

Clinical System Name

Breath Tolerance Carbohydrate Malabsorption

Description

This test must be scheduled in advance with the Chemistry Lab. (206)987- 3860. The ordering provider should specify challenge (fructose, lactose, sucrose).

 

Patients must be off of antibiotics for two weeks and should fast for 10 h prior to test.  A 6 h fast is acceptable for infants. An elevated fasting (baseline) breath sample can be seen with colonic fermentation or bacterial overgrowth.

 

 

Sample Requirements

Specimen: Breath

Container(s):

Preferred Vol:

Minimum Vol:

 

Note: Diabetic patients will have a fasting blood glucose collected and run before the procedure is started.

Performing Laboratory

Seattle Children's Laboratory    

 

Department

Department:  Chemistry

Location: Chem East

Phone Number: (206) 987-3860

 

Synonyms

Breath hydrogen and methane tolerance

Fructose

Lactose

Sucrose

Availability

STAT Performed TAT
N M, W, Th, day shift 1 d

 

Test must be scheduled with chemistry lab (206) 987-3860.

Methodology

Method: Gas Chromatography

Analytical Volume:

Limitations:

Reference Range

 

  Rise in expired hydrogen over baseline Rise in methane
Carbohydrate Intolerance <20 ppm < 10 ppm

A rise of > 20 ppm H2 above baseline after a carbohydrate (fructose, lactose, sucrose) challenge is positive for fructose, lactose, or sucrose malabsorption. Carbohydrates may also be malabsorbed in the presence of SIBO.

  1. If both H2 and CH4 increase, the two can be summed, although there is not consensus on interpretation.
  2. Highest elevation is typically seen by 90-120 min. The test samples breath every 30 minutes for 2 ½ hours.
  3. If a patient has a high fasting baseline H2 or CH4, it may be due to:
    1.  Food remaining in the colon (patient has not fasted, or did not avoid complex carbohydrates prior to testing)
    2.  Smoking
    3. Patient has SIBO
  4. High CH4 (>10 ppm) alone has been linked to chronic constipation.

Reference:
Rezaie A, et al, Hydrogen and methane-based breath testing in gastrointestinal disorders: The North American consensus. The American Journal of Gastroenterology 2107;112:775-784.

 

CPT Codes

91065