Ketone Bodies, Serum
| Ketone Bodies, Serum | | | |
| Number | | 004887 |
| CPT | | 82009 |
| Synonyms | | Acetest® ; Acetoacetate ; Acetone, Semiquantitative, Serum ; Blood Acetone ; Ketones, Semiquantitative, Blood ; Nitroprusside Reaction |
| Test Includes | | Detection in serum of acetone and acetoacetic acid only |
| Special Instructions | | Lactic acid, phosphorus, and electrolytes should also be measured in possible ketoacidosis. |
| Specimen | | Serum |
| Volume | | 1 mL |
| Minimum Volume | | 0.1 mL |
| Container | | Red-top tube or gel-barrier tube |
| Collection | | If a red-top tube is used, transfer separated serum to a plastic transport tube. Capillaries should be filled as much as possible using technique to avoid air bubbles. Free flowing heelstick. Cap sample to prevent acetone evaporation. |
| Storage Instructions | | Refrigerate |
| Reference Interval | | None detected |
| Use | | Diagnose ketonemia, ketoacidosis resulting from diabetes mellitus,1 alcoholism, stress,2 starvation, intestinal disorders including emesis, glycogen storage disease (von Gierke), infantile organic acidemias, and other metabolic disorders. Determining the presence of ketone bodies is useful when isopropanol ingestion is suspected. |
| Limitations | | False-negatives or falsely weak reactions may occur. Up to 33% of cases of diabetic ketoacidosis also have lactic acidosis. Acidosis shifts ketone bodies to β-hydroxybutyrate; however, β-hydroxybutyrate is not measured by nitroprusside, which reacts with both acetoacetic acid and acetone.2 The reagent is 5-20 times more sensitive to acetoacetic acid than to acetone and does not react with β-hydroxybutyrate. Thus, as ketoacidosis is treated, an apparent positive Acetest® is found while there is an actual reduction of total plasma ketone body concentration. Acidosis shifts equilibrium toward β-hydroxybutyrate (unmeasured) but treatment of ketoacidosis results in increased acetoacetate (measured) and thus a more positive “acetone” reaction, before ketone bodies decrease.2 Nonketotic coma in diabetes may be caused by hyperosmolarity.3 |
| Methodology | | Nitroprusside reaction (Acetest®) |
| Additional Information | | Strongly positive serum acetone without severe acidosis, with normal anion gap, bicarbonate and plasma glucose suggests the possibility of rubbing alcohol intoxication. Look for dehydration with ketosis.1 Ketoacidosis in diabetes usually occurs with decreased plasma pH and bicarbonate, increased glucose and other abnormalities. As ketoacidosis and metabolic acidosis are treated, hypokalemia may become evident. A normal or low potassium on admission of a patient with ketoacidosis may indicate severe potassium depletion.1 Thus, potassium is among the parameters to follow in treatment of ketoacidosis. Hypophosphatemia may evolve. Acetone may be elevated due to absolute or relative starvation, especially in children. A significant mortality rate exists; in children younger than 10 years of age, diabetic ketoacidosis is reported to account for 70% of diabetes related deaths.4 |
| Footnotes | | - Bienia R and Ripoll I, “Diabetic Ketoacidosis,” JAMA, 1979, 241(5):510-1.
- Schade DS and Eaton RP, “Differential Diagnosis and Therapy of Hyperketonemic State,” JAMA, 1979, 241(19):2064-5.
- Vaisrub S, “Hyperosmolar Diabetic Coma - Ketotic and Nonketotic,” JAMA, 1974, 227(3):317-8 (editorial).
- Bonadio WA, Gutzeit MF, Losek JD, et al, “Outpatient Management of Diabetic Ketoacidosis,” Am J Dis Child, 1988, 142(4):448-50
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