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Test Code LAB2390 Breath Tolerance Bacterial Overgrowth

Important Note

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

 

Lactulose breath testing is restricted for patients >4 years old. Orders received for patients younger than 4 years old will be canceled

Clinical System Name

Breath Tolerance Bacterial Overgrowth

Synonyms

Glucose breath hydrogen

 

SIBO (Small Intestinal Bacterial Overgrowth)

Lactulose breath hydrogen

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.

 

Availability

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

 

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

Performing Laboratory

Seattle Children's Laboratory    

 

Department

Department:  Chemistry

Location: Chem East

Phone Number: (206) 987-3860

 

CPT Codes

91065

Methodology

Method: Gas Chromatography

Analytical Volume:

Limitations:

Reference Range

An interpretation will accompany the report.

Description

This test is to detect bacterial overgrowth and must be scheduled in advance with the Chemistry Lab. (206)987- 3860.  Patients must be off of antibiotics for two weeks and should fast for 12 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.

The ordering provider should specify glucose or lactulose. If glucose is given, the test will last 2 hours; a lactulose challenge will last 3 hours.

Clinical Utility

Small Intestinal Bacterial Overgrowth (SIBO)/ Lactulose or glucose challenge:
    
1.    Glucose is absorbed in proximal bowel; lactulose travels to colon.
2.    Fermentation of the malabsorbed lactulose by bacteria in the small intestine results in elevated levels of breath H2 or CH4 in SIBO.
3.    A rise of H2 > 20 PPM over baseline in the first 100 minutes of testing is potentially positive for SIBO.
4.    A rise in H2 of > 20 PPM over baseline in samples collected after 100 minutes may be positive for SIBO in patients with slower transit times or chronic constipation.
5.    Normal individuals may have a modest rise in hydrogen as the lactulose enters the colon, after 90 minutes.
6.    Presence of methane gas may slow intestinal transit time; patients with methane predominant bacterial overgrowth are more likely to have 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.