Effect Of Room Temperature And Refrigerated Storage On Automated Hematological Parameters And Peripheral Blood Smear Examinations

Abstract

Background: Complete blood count and morphological assessment of peripheral blood smear examination are the most common investigations done in laboratory in order to give crucial information about disease and its final diagnosis. Blood samples are commonly sent from the clinical lab after an extended post-collection period. The laboratory must determine whether to accept or reject such a sample when it is delivered. If the specimen is approved, the laboratory must next choose whether to carry out all the tests requested or just those necessary, given the specimen's age and also choose what remarks should be added to the reported results reflecting the accuracy or limits of the analysis.

Aim: To evaluate the variation in hematological parameters on automated hematological analyzer and peripheral blood smear examination of samples stored at room temperature and samples stored at refrigerated temperature (2-8⁰C).

Materials and methods: Blood samples were collected from 60 patients. Hematological parameters like Hemoglobin, HCT, MCV, MCH, MCHC, Platelet count, red blood cell and White blood cell count were analyzed in room temperature storage and refrigerated storage at 2-8⁰C for 24 hours (30 samples each) using automated hematology analyzer. Peripheral blood smear from samples stored at room temperature and at 2-8⁰C in refrigerators for 24 hours were also examined.

Result: This study showed hematological parameters affected when stored at room temperature were RBC, HCT, MCV, MCH, MCHC, RDW and Platelet count. Hemoglobin and WBC Counts were not affected after 24-hour storage at room temperature. While at 2-8⁰C refrigeration, all the hematological parameters were stabilized and changes were not statistically significant. Morphological changes like crenated RBCs, increased size of platelet and vacuolated WBCs were seen peripheral blood smear examination.

Conclusion: This study emphasizes to assay hematological parameters and peripheral blood smear examination immediately after sample collection in order to prevent the misinterpretation of results. Standardized storage conditions reduce pre-analytical variation and the hematological parameters affected by storage and temperature in a way that could influence clinical decisions.  Therefore, to provide an accurate report if there is a known delay in the interpretation of the sample, refrigeration of EDTA blood samples at 2-8⁰ C is advised.