Analyzing the stability of biochemical parameters, based on time and temperature, at a tertiary care laboratory

Abstract

Laboratories play a critical role in helping clinicians to make a correct decision, as a part of Evidence-based medicine. Laboratory errors lead to delay in reporting and necessity for a repeat sample which may cause serious discomfort to the patients, pre-analytical error being a major contributor. This study is focused on studying the optimal time limit and storage temperature of certain biochemical parameters, to ensure quality in sample handling and storage.The study included 50 serum samples, analyzed for the biochemical parameters Glucose, creatinine, amylase, sodium, potassium, bicarbonate and calcium at different time intervals (0, 3 and 6 hours) and storage conditions (2-4 and -20 degree Celsius after 24 hours).Glucose, creatinine, amylase, sodium, potassium and calcium were found to be stable at 3 and 6 hours, after the initial processing. These parameters were stable for 24 hours at 2-4 degree Celsius and at -20 degree Celsius as well. Bicarbonate in contrast revealed a significant change in the values when analyzed, based on the given procedure.To maintain the precision and accuracy in the tertiary care laboratory, the plasma and serum sample, once centrifuged shall be processed for estimating the biochemical parameters like glucose, creatinine, amylase, sodium, potassium and calcium up to 6 hours at the analyzer room temperature (20-24 degree Celsius), and shall be stored for 24 hours at 2-4 degree Celsius and at -20 degree Celsius. Unlike other parameters, serum bicarbonate has to be analyzed as early as the sample is centrifuged and separated.