Plasma ketone body

There are three ketone bodies in clinical trial diagnosis. They are acetoacetate and beta-hydroxybutyrate with two keto acids, which are present in ionic form in a physiological pH environment, and acetone without keto acid. Increased anion gap and metabolic acidosis in the presence of ketone bodies Diabetes and alcohol are common causes. In the case of intensive care unit, one out of every four diabetic acidosis is alcoholic ketoacidosis.

Basic Information

Specialist classification: Digestive examination classification: biochemical examination

Applicable gender: whether men and women apply fasting: fasting

Tips: Before the examination, the diet is light and alcohol is prohibited. Check for an empty stomach in the morning. Normal value

After a night of fasting, β-hydroxybutyrate in the blood was 0.02 to 0.27 mmol/L (0.21 to 2.81 mg/dl).

After an overnight fasting, the ketone body in the urine was <0.48 mmol/L (5 mg/dl). (Conversion formula mg/dl×0.096=mmol/L.)

Clinical significance

Ketone bodies are also different in different types of metabolic acidosis. Metabolic acidosis usually results from one of the following conditions:

1. Increases in the production of organic acids such as beta-hydroxybutyrate and acetoacetate are associated with diabetes or alcohol or lactic acidosis, such as in tissue perfusion disorders. Excretion of cations and ketone bodies in the urine increases.

2. HCO3- is lost, such as diarrhea caused by loss of duodenal fluid. As the blood sodium concentration decreases, the blood chlorine concentration generally increases.

3. Reduction of acid excretion, as a result of renal insufficiency or renal tubular acidosis.

The criteria for evaluating metabolic acidosis are:

1. Calculation of anion gap, normal value is 8-16 mmol/L, anion gap (mmol/L) = [Na+]-([Cl-]+[HCO3-]).

2. Determination of beta-hydroxybutyrate and possibly acetoacetate in serum or semi-quantitative detection of ketone bodies.

(1) Normal anionic gap metabolic acidosis: This type of metabolic acidosis is associated with hyperchloric acidemia. Possible causes include potential renal tubular acidosis, carbonic anhydrase inhibitor intake, and hyperkalemia acidosis.

(2) Metabolic acidosis with increased anion gap: metabolic acidosis caused by ketoacidosis, lactic acidosis, renal failure, salicylate poisoning and alcoholic poisoning, etc., can make blood chlorine normal or Occasionally reduced.

(3) Increased anion gap and metabolic acidosis in the presence of ketone bodies: diabetes and alcohol are common causes. In the case of intensive care unit, one out of every four diabetic acidosis is alcoholic ketoacidosis.

(4) Ketoacidosis: In ketoacidosis, accumulation of anionic β-hydroxybutyrate and acetoacetate in plasma leads to an increase in the anion gap, which is proportional to the decrease in the concentration of bicarbonate ions.

Renal excretion is directly dependent on the glomerular filtration rate, as the reabsorption of the two anions in the kidney is only 75% to 85%. Therefore, there is a quantitative relationship between blood ketone and urinary ketone in the case of a healthy kidney function. It has been confirmed that when the blood ketone (β-hydroxybutyrate + acetoacetate) reaches 0.8 mmol/L (8 mg/dl), the urine routine gives a positive result of the plus. When the blood ketone reaches 1.3 mmol/L (13 mg/dl), the urine routine has three plus positive results. However, because urine routinely fails to detect beta-hydroxybutyrate, approximately 10% of patients with only beta-hydroxybutyrate accumulation in the body can produce negative results.

The syndrome is mainly a hyperglycemia state in which the non-ketotic anion gap is normal caused by dehydration caused by metabolic decompensation of type II diabetes. It is different from diabetic ketoacidosis.

High results may be diseases: diabetic ketoacidosis, metabolic acidosis, non-ketotic hyperglycemia - hyperosmolar coma precautions

1. Analytical sensitivity of the rapid test: β-hydroxybutyric acid was not detected when acetoacetic acid 0.5 g/L and acetone 5 g/L.

2, stability: acetoacetate instability can be quickly converted to β-hydroxybutyrate and acetone. Therefore, if acetoacetate is to be detected, the sample must be added with perchloric acid immediately. Β-hydroxybutyric acid in whole blood can be stored for 4 h at 4-8 ° C, and stored for 48 h in serum or plasma.

Inspection process

Immediately after venous blood collection, the detection method is theoretically feasible although all three ketone body serum and urine quantitative determinations are practical, but from a practical point of view, the following methods are commonly used: quantitative serum detection of β-hydroxybutyrate, less acetoacetate use. Rapid determination of ketone bodies in urine: These experiments can also be used to dilute serum.

Not suitable for the crowd

Special diseases: Patients with hematopoietic dysfunction, such as leukemia, various anemia, myelodysplastic syndrome, etc., unless the examination is essential, try to draw less blood.

Adverse reactions and risks

Subcutaneous hemorrhage: subcutaneous hemorrhage due to less than 5 minutes of compression time or blood draw technique.