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HelpTest Code BHYD Beta-Hydroxybutyrate, Serum
Reporting Name
Beta-Hydroxybutyrate, SUseful For
Monitoring therapy for diabetic ketoacidosis
Investigating the differential diagnosis of any patient presenting to the emergency room with hypoglycemia, acidosis, suspected alcohol ingestion, or an unexplained increase in the anion gap
In pediatric patients, the presence or absence of ketonemia/uria is an essential component in the differential diagnosis of inborn errors of metabolism
Serum beta-hydroxybutyrate is a key parameter monitored during controlled 24-hour fasts
Method Name
Photometric, B-Hydroxybutyrate Dehydrogenase (B-HBDH)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Serum gel tubes should be centrifuged within 2 hours of collection.
2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 7 days | |
| Refrigerated | 7 days |
Reject Due To
| Gross hemolysis | Reject |
Reference Values
<0.4 mmol/L
Day(s) Performed
Monday through Sunday
CPT Code Information
82010
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| BHYD | Beta-Hydroxybutyrate, S | 6873-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| BHYD | Beta-Hydroxybutyrate, S | 6873-4 |
Clinical Information
Beta-hydroxybutyrate (BHB) is 1 of 3 sources of ketone bodies. Its relative proportion in the blood (78%) is greater than the other 2 ketone bodies, acetoacetate (20%) and acetone (2%). During carbohydrate deprivation (starvation, digestive disturbances, frequent vomiting), decreased carbohydrate utilization (diabetes mellitus), glycogen storage diseases, and alkalosis, acetoacetate production increases. The increase may exceed the metabolic capacity of the peripheral tissues. As acetoacetate accumulates in the blood, a small amount is converted to acetone by spontaneous decarboxylation. The remaining and greater portion of acetoacetate is converted to BHB.
Interpretation
The beta-hydroxybutyrate (BHB)/acetoacetate ratio is typically between 3:1 and 7:1 in severe ketotic states.
Serum BHB increases in response to fasting, but should not exceed 0.4 mmol/L following an overnight fast (up to 12 hours).
In pediatric patients, a hypo- or hyper-ketotic state (with or without hypoglycemia) may suggest specific groups of metabolic disorders.
Cautions
Twenty four-hour fasting tests should not be performed in patients <2 years of age.
Dipstick serum ketone determination using nitroprusside reagent is often used to estimate ketone body status, but that method has inherent problems. The dipstick does not measure beta-hydroxybutyrate, the most abundant of the physiological ketone bodies; the nitroprusside reagent only reacts with acetoacetate and acetone.
Method Description
D-3-hydroxybutyrate in the presence of NAD is converted to acetoacetate and NADH at pH 8.5 by D-3-hydroxybutyrate dehydrogenase. At this pH the reaction is favored to the right. The NADH is converted to a colored compound using INT and Diaphorase.(Package insert: Stanbio Beta-hydroxybutyrate LiquiColor Procedure No. 2440; DN: RBR.2440.00, 4/16/2002)