Stability of common biochemistry analytes in equine blood stored at room temperature.
Authors: Rendle D I, Heller J, Hughes K J, Innocent G T, Durham A E
Journal: Equine veterinary journal
Summary
# Editorial Summary: Stability of Common Biochemistry Analytes in Equine Blood Stored at Room Temperature Recognising that delays between blood sampling and laboratory analysis are inevitable in equine practice, Rendle and colleagues investigated how storage at room temperature affects the reliability of biochemical results. Blood samples from 20 horses were held as clotted whole blood, separated serum, and plasma, then analysed at 0, 24, 48 and 72 hours; statistical analysis included Bland-Altman plots and paired t-tests to assess clinically significant changes. Storage delays of up to 72 hours produced measurable increases in aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total bile acids and magnesium, whilst glucose concentrations declined notably in both serum and plasma samples. Whilst these changes were statistically significant, the authors concluded that for most practical situations involving multi-analyte screening over a few days' delay, results remain interpretable; however, serum separation immediately after clotting offered only marginal protective benefit. These findings provide practitioners with evidence-based context for interpreting results when processing delays have occurred, particularly valuable for single-analyte concerns or cases where slight numerical shifts might influence clinical decision-making.
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Practical Takeaways
- •Blood samples delayed 24-72 hours before processing may show clinically relevant changes in certain analytes (especially muscle enzymes and glucose); consider timing when interpreting unexpected results
- •Routine practice of separating serum immediately after clotting provides minimal protection—focus instead on minimizing delay time between collection and analysis
- •When delays occur, reference the published data to interpret results; multiple analytes showing consistent patterns are more reliable than isolated abnormal values in delayed samples
Key Findings
- •Delays up to 72 hours in blood processing resulted in significant increases in aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total bile acids, and magnesium
- •Glucose showed significant decrease in serum and oxalate fluoride plasma over 72 hours
- •Serum separation immediately after clot formation provided only limited protective benefit against time-related changes
- •In most clinical cases with delays of only a few days and multiple concurrent analyte assessment, results interpretation is unlikely to be significantly affected