EBM Consult

Lab Test: Ketones (Serum) Level

    Lab Test
    • Ketones (Serum)
    Description
    • Measurement of serum or plasma ketones, specifically acetoacetate, for analysis of ketone-producing glycogenolytic disorders
    Reference Range
    • Negative:  < 1 mg/dl (< 0.1 mmol/L)
    Indications & Uses
    • Initial evaluation of suspected hyperglycemic hyperosmolar state (HHS)
      • Serum ketones are sometimes low in HHS. 
    • Suspected alcoholic ketoacidosis (AKA)
      • Elevated serum ketones in a patient with a history consistent with alcoholic ketoacidosis.   
    • Suspected and known diabetic ketoacidosis (DKA)
      • Positive serum ketones are part of the diagnostic criteria for mild, moderate, and severe diabetic ketoacidosis (DKA).  
      • Ketonemia usually takes longer to clear than hyperglycemia does.
    Clinical Application

    • The nitroprusside reaction is a semi-quantitative test that detects only acetoacetate and acetone.  
    • The predominant ketone formed by ketogenesis is beta-hydroxybutyrate.  
    • Test results should be interpreted with caution, as acetoacetate levels alone may not accurately reflect serum ketone levels at diagnosis or during the treatment of DKA.

    Procedure
    • Collect plasma or serum specimen after overnight fast.
    Storage and Handling
    • Cover specimen and transport immediately to laboratory.
    • Avoid hemolysis.
    • If analysis is not performed immediately, freeze specimen at -80°C to avoid significant acetoacetate degradation and false results.
    References
    • Foreback CC. B-hydroxybutyrate and acetoacetate levels. Am J Clin Pathol 1997;108:602-4.
    • LaGow B et al., eds. PDR Lab Advisor. A Comprehensive Point-of-Care Guide for Over 600 Lab Tests.  First ed. Montvale, NJ: Thomson PDR; 2007.
    • Porter WH et al. Laboratory and clinical evaluation of assays for B-hydroxybutyrate. Am J Clin Pathol 1997;107:353-8.

MESH Terms & Keywords

  • Ketones