Specimen Requirements
Title
LACTIC ACID (LACTATE)
Specimen Requirement
Collect sodium fluoride, potassium oxalate or sodium heparin, 1 mL plasma required.
Begin with collection tube on ice. Mix well by gentle inversion at least six times. Return to ice bath to cool. Centrifuge within 15 minutes and immediately transfer plasma to a screw top plastic vial, indicate sample type on transport tube. Avoid excessive forces that contribute to hemolysis.
Avoid hand-clenching and, if possible, avoid use of a tourniquet. Use of a tourniquet or patient clenching and unclenching hand will lead to high potassium and lactic acid buildup, and pH will decrease. It is best to avoid a tourniquet for electrolytes and lactic acid or to release it after blood begins to flow into the tube. If the tourniquet is released before blood is drawn, wait about a minute before drawing.
Methodology
Lactate−pyruvate; spectrophotometry
Stability
Room temp: 14 days, Refrigerated: 14 days, Frozen: 14 days
Reference Range
By Report*
Turnaround
1-3 days
Clinical Use
Hypoperfusion is the most common cause of lactic acidosis and hyperlactacidemia may be the only marker of tissue hypoperfusion. Suspect lactic acidosis when unexplained anion gap metabolic acidosis is encountered, especially if azotemia or ketoacidosis are not present. Evaluate metabolic acidosis, regional or diffuse tissue hypo perfusion, hypoxia, shock, congestive heart failure, dehydration, complicated postoperative state, ketoacidosis or nonketotic acidosis in diabetes mellitus, patients with infections, inflammatory states, postictal state, certain myopathies, acute leukemia and other neoplasia, enzyme defects, glycogen storage disease (type I), thiamine deficiency, and hepatic failure. A spontaneous form of lactic acidosis occurs. It is a prognostic index in particular clinical settings, especially in critically ill patients in shock. A relationship to renal disease also exists. With skin rash, seizures, alopecia, ataxia, keratoconjunctivitis, and lactic acidosis in children, consider defective biotin metabolism. Phenformin, ethanol, methanol, and salicylate poisoning and ethylene glycol may cause lactic acidosis. Acetaminophen toxicity causes lactic acidosis, sometimes with hypoglycemia. Cyanide, isoniazid, and propylene glycol are among the causes of lactic acidosis. Lactic acidosis may be due to inborn errors of metabolism.
Test Code
LAAM