Preanalytical Errors in Clinical Chemistry Laboratory

There are many factors that contribute to accurate test results in the chemistry laboratory. These factors can be broken down into three areas: preanalytical, analytical and post analytical. Preanalytical variables account for 32-75% of laboratory errors, and encompass the time from
when the test is ordered by the physician until the sample is ready for analysis. The focus of this article will be preanalytical variables that can occur during a venipuncture and specimen processing and how they relate to testing in the clinical chemistry laboratory.

There are many variables that can contribute to the quality of a chemistry specimen. This article will investigate the variables that may have contributed to the gelatinous specimen in the case of the cardiac patient, as well as the other variables that are important to specimen quality. The focus will be on the preanalytical phase of the blood collection and sample handling, up until the time that the sample is to be run on the chemistry instrument.

Preanalytical variables:

• Patient Identification
• Patient Preparation
• Selecting the Site
• Site Preparation
• Tourniquet Application and Time
• Proper Venipuncture Technique
• Order of Draw
• Proper Tube Mixing
• Correct Specimen Volume
• Proper Tube Handling and Specimen Processing
• Centrifugation
• Special Handling of Blood Specimens
• Stability for Whole Blood, Serum and Plasma             

Read more:
Preanalytical Variables in the Chemistry Laboratory


Source: BD