Specimen Validity Testing
S pecimen validity testing (SVT) is an essential component of clinical laboratory test- ing, ensuring the accuracy and reliability of results. SVT involves the assessment of a patient's sample integrity to confirm that the specimen collected is suitable for analysis and has not been tampered with or adulterated. The information provided by SVT is critical for interpreting test results accurately and making informed clinical decisions.
2.2 Blood Specimen Validity Testing: For blood samples, specimen validity testing may include assessing sample hemolysis (rupturing of red blood cells), lipemia (excess fat in the blood), and icterus (excess bilirubin in the blood). Hemolyzed or lipemic samples can interfere with certain tests, affecting the accuracy of results. Common Adulteration and Dilution Methods 3.1 Adulteration: Adulteration refers to the intentional addition of substances to a speci- men to interfere with test results or mask the presence of drugs or oth- er analytes. Common adulterants include bleach, vinegar, and various commercial products marketed as urine "cleansers." Specimen validity testing helps detect the presence of adulterants and ensures the reli- ability of drug test results. 3.2 Dilution : Dilution involves adding water or other liquids to a specimen to re- duce the concentration of drugs or analytes, potentially leading to false-negative results. In drug testing, dilution may be an attempt to evade detection of drug use. Specimen validity testing helps identify dilute samples and alerts healthcare providers to potential issues with patient compliance or substance misuse.
Specimen validity testing is crucial for maintaining the integrity of laboratory testing processes. Inaccu- rate or compromised test results can lead to misdiag- nosis, inappropriate treatments, and potential harm to patients. By assessing sample integrity, SVT helps identify potential issues with the collection, handling, or transportation of specimens, ensuring that the results obtained are a true reflection of the patient's condition. Types of Specimen Validity Testing 2.1 Urine Specimen Validity Testing: In drug testing and certain clinical analyses, urine samples are commonly used. Urine specimen validity testing aims to detect potential adulteration, dilution, or substitution of the sample. Parameters assessed may include pH, specific gravity, creatinine levels, and the presence of oxidizing agents or masking sub- stances.
28 | Marshfield Labs Magazine
Made with FlippingBook - professional solution for displaying marketing and sales documents online