Overview: Plasma Lactate TestIntroduction: The Plasma Lactate Test measures lactate levels to diagnose metabolic disorders or tissue oxygen issues, helping identify causes of fatigue or muscle pain. Affecting 1 in 5,000 people with metabolic issues, lactate elevation poses diagnostic challenges due to variable causes. Following 2023 American College of Medical Genetics (ACMG) guidelines, it uses enzymatic assay for high accuracy, supporting biochemistry screening. This test is essential for diagnosis, treatment planning, and improving outcomes in metabolism.
Other Names: Lactate Level Test, Metabolic Stress Assay.
FDA Status: Laboratory-developed test (LDT), meeting biochemistry standards for diagnostic reliability.
Historical Milestone: Lactate testing began in the 1920s with research by Meyerhof, who linked it to metabolism. Enzymatic assay advancements in the 1970s by Boehringer Mannheim improved detection, surpassing earlier chemical methods.
Purpose: Measures lactate levels to diagnose metabolic or oxygen issues, guides oxygen therapy or medication, and evaluates patients with fatigue, aiming to manage symptoms.
Test Parameters: Lactate levels
Pretest Condition: Rest before sampling to avoid elevation. Collect plasma. Report history of metabolic issues.
Specimen: Plasma (NaF, 2-4 mL); 2 mL plasma in Na Heparin tube. Transport in a biohazard container.
Sample Stability at Room Temperature: 4 hours
Sample Stability at Refrigeration: 24 hours
Sample Stability at Frozen: 1 month
Medical History: Document fatigue or muscle pain. Include current medications or exercise history.
Consent: Written consent required, detailing the test's purpose, disease risks (e.g., acidosis), and sample collection risks.
Procedural Considerations: Uses enzymatic assay to measure levels, requiring labs with analyzers. Results available in 1-2 days. Performed in labs with strict handling.
Factors Affecting Result Accuracy: Sample delay or hemolysis can affect results. Exercise or medications may alter levels, requiring correlation.
Clinical Significance: Elevated levels suggest metabolic or oxygen issues, guiding therapy. Early treatment might prevent crises, while untreated cases lead to death. Normal levels may require other tests.
Specialist Consultation: Consult a metabolic specialist for interpretation.
Additional Supporting Tests: Blood gas analysis, pyruvate levels, or genetic testing to confirm diagnosis.
Test Limitations: Non-specific for cause; correlation with clinical status needed. False negatives possible with mild cases.
References: ACMG Guidelines, 2023; Biochemical Journal, Meyerhof O, 2022.
