What effect does a tilted tube have on the ESR results?

A tilted tube can lead to an increased erythrocyte sedimentation rate (ESR) due to the impact on the plasma and red blood cell distribution as the sample settles. When a tube is not placed vertically, it causes an uneven distribution of blood cells and plasma, which can interfere with the sedimentation process. This disruption often leads to a situation where red blood cells settle more slowly or are ‘trapped’ by the plasma proteins, preventing accurate measurement of the rate at which they fall.

By increasing the distance the cells need to fall or altering how they aggregate, the tilt can misrepresent what would have been a normal rate in a properly oriented tube. Therefore, the correct observation is that a tilted tube results in an increase in the ESR readings, reflecting an inaccurate representation of the sample's true sedimentation characteristics.