If a blood sample is delayed for 4.5 hours, which tests could still be considered reliable?

In the scenario where a blood sample is delayed for 4.5 hours, the reliability of test results is influenced by the stability of the analytes in the sample. Uric acid, blood urea nitrogen (BUN), and creatinine are generally stable in serum for extended periods at room temperature, meaning that they can still provide reliable results even after a delay of several hours.

Uric acid is not significantly affected by delay and can reflect accurate levels even if the sample is not processed immediately. Similarly, BUN and creatinine remain stable over time, allowing for dependable measurements. These analytes are less likely to show degradation or alterations due to delays in processing compared to other components that might be more sensitive to time and temperature changes.

In contrast, other analytes in the other groups may not maintain their integrity as effectively. For instance, glucose can undergo glycolysis, leading to lower readings over time. Enzymes and other substances like ALT, AST, and CK may also change in activity levels, impacting their measurement reliability.

By understanding the stability of these analytes, one can determine which tests could still yield reliable results when there's a delay in processing the blood sample.