Which blood component tends to influence the measurement of serum potassium the most?

The measurement of serum potassium concentration can be significantly influenced by the presence of thrombocytes, or platelets, in the blood sample. When a blood sample is drawn, potassium can leak out of the cells, particularly from thrombocytes, into the serum. This effect is especially pronounced if the sample is hemolyzed, as the release of potassium from the intracellular environment of these cells can artificially elevate the measured serum potassium levels.

In situations where thrombocytosis (an elevated platelet count) is present, the amount of potassium released into the serum can be substantial, leading to potentially misleading laboratory results. Therefore, when interpreting serum potassium levels, it's critical to consider the platelet count as it can have a direct impact on the accuracy of the potassium measurement.

Other components in the blood, such as hemoglobin, leukocytes, and plasma proteins, do not have the same level of direct influence on potassium levels as thrombocytes do, although they may affect other aspects of sample integrity and analysis.