🏾 Sommaire :
🏾 Overview
Lactate is a biomarker that has long been used to assess the extent of tissue hypoxia during different disease states. It has been particularly studied during states of shock and during serious septic states.
Lactate is an intermediate metabolite of glycolysis, produced by the tissues of the body (mainly in the muscles) during energy production when oxygen supply is insufficient (anaerobic).
Lactate is the ionized form of lactic acid, depending on the pH, it is sometimes present as lactic acid if the Ph is acidic and as lactate if the Ph is neutral.
A lactic acid test is most often used to diagnose lactic acidosis, states observed in various pathological situations: septic shock, ketoacidotic diabetes, intoxications. etc
🏾 What is the lactate test used for? ?
A lactic acid test is most often used to diagnose lactic acidosis. Symptoms of lactic acidosis include rapid breathing, excessive sweating, cold, clammy skin, odorous breath, abdominal pain, nausea or vomiting, confusion and coma.
The test can also be used to:
- Helps know if enough oxygen is reaching body tissues
- Helps diagnose sepsis.
- Find the cause of a high amount of acid (low pH) in the blood.
🏾 How the test is done ?
A healthcare professional will take a sample of blood from a vein or artery. Sometimes a sample of cerebrospinal fluid is taken by spinal tap.
It is okay not to exercise for several hours before the test. Exercise can cause a temporary increase in lactic acid levels.
The use and release of the tourniquet and the clenching of the fist can increase lactate levels in the blood sample.
In some cases, the healthcare professional may ask you not to eat or drink anything other than water for 8 to 10 hours before the test (lactemia increases in the post-prandial period and in cases of alcoholism).
🏾 The results
Normal lactate results range from 4.5 to 19.8 milligrams per deciliter (mg/dL) (0.5 to 2.2 millimoles per liter [mmol/L]).
Note: Expected values may vary by age, gender, diet, and geographic location. Each laboratory should determine its own expected values according to good laboratory practice.
Excess lactate may indicate one or a combination of the following:
- Lack of oxygen (hypoxia)
- The presence of a condition that causes increased lactate production
- The presence of a condition that causes a decrease in the clearance of lactate from the body
They are separated into two groups according to the mechanism by which they cause lactic acidosis:
Lactic acidosis type A related to insufficient oxygen supply, the most common type, associated with tissue hypoxia:
- Circulatory failure acute
- Organ ischemia
- Severe hypoxemia
- Pathology of hemoglobin
- Sepsis
- Seizures
Lactic acidosis type B related to excessive oxygen demand or metabolic problems, is not associated with tissue hypoxia:
- Liver disease
- Use of catecholamines
- Kidney disease
- Uncontrolled diabetes
- Leukemia
- AIDS
- Inborn abnormalities of the metabolism
- Poisoning: Ethylene glycol, Methanol, Biguanides