Importance of measurement temperature in detecting the alterations of red blood cell aggregation and deformability studied by ektacytometry: a study on experimental sepsis in rats.

It is well known that RBC rheological parameters are affected by temperature. Usually, the measurement temperature of these parameters is kept constant throughout a given study, however it can be seen that different temperatures are used by different groups, during the measurement of a given parameter. It is assumed that the data should not be qualitatively different when measured at different temperatures, although significant quantitative differences exist. This study revealed that the selected temperature for RBC elongation index measurements by ektacytometry is important in detecting a given impairment in RBC deformability induced by experimental sepsis. RBC elongation indexes were found to be significantly different in septic and normal rats, only if measured at 37 degrees C. The differences in RBC aggregation parameters for septic and normal rats were also affected by the measurement temperature, however statistically significant differences were present in a wider range of temperatures between 25-37 degrees C. Therefore, it is strongly recommended that the measurement of RBC deformability and aggregation be performed using a controlled-temperature device, set to 37 degrees C.