[Verification of complete blood cell count (CBC) data from heparinized blood gas samples]

Complete blood cell count (CBC) data from heparinized blood gas (H-Gas) samples were verified with primary focus on the platelet count (PLT). When a part of H-Gas sample was taken to a separation tube from the blood collection syringe and CBC of the sample in the separation tube was repeatedly measured (Procedure 1), the PLT from 5 samples relative to that obtained immediately after the separation was gradually reduced to 72.6-94.2% during serial measurements (every 5 minutes, up to 30 minutes). The change in the scattergram pattern suggested that this PLT decrease was due to the formation of platelet clumps. The white blood cell count (WBC), red blood cell count (RBC), hemoglobin (Hb) and hematocrit (Ht) values did not significantly change during the repeated measurements. On the other hand, PLT was significantly improved to 96.8-99.8% when the H-Gas sample was kept in the blood collection syringe so as to minimizing the exposure to the air, and the sample for the measurement from H-Gas was taken every time to separation tube from the syringe, followed by CBC measurement without delay (Procedure 2). In addition, while there were significant variations (CV: 11.8-18.2%) in PLT reproducibility among H-Gas samples by Procedure 1, measurements utilizing the Procedure 2 resulted in much smaller variations (CV: 2.2-3.7%). Thus the CBC data obtained from H-Gas samples were equivalent to those from EDTA samples when the Procedure 2 was applied. These data suggest that H-Gas samples can be used for the accurate CBC measurement, including PLT, by applying the Procedure 2.