To compared the effects of sodium citrate anticoagulation, amikacin supplement, magnesium sulfate supplement and predilution method on the determination of platelets in EDTA-PTCP (Ethylene Diamine Tetraacetic Acid Dependent pseudobocytopenia).

After confirming the patients with EDTA-PTCP, whole blood samples were collected simultaneously in EDTA-K₂ and sodium citrate anticoagulated tubes. Amikacin (6.5 mg/mL) and magnesium sulfate (25 mg/mL) were added after aspiration of EDTA-K₂ treated whole blood. Samples anticoagulated with EDTA-K₂ and sodium citrate, supplemented with amikacin and magnesium sulfate were tested for their platelet counts at 0 h, 1 h, 2 h, 3 h and 4 h, respectively. Platelet aggregations were also confirmed by microscopic examination at 0 h, 1 h, 2 h, 3 h and 4 h, respectively. In addition, we collected the peripheral blood of patients with EDTA-PTCP for pre dilution mode testing and manual counting.

Thirty-three patients with EDTA-PTCP were confirmed in The Second Affiliated Hospital of Guangzhou Medical University from July 2019 to January 2020. Platelet aggregations disappeared in 3 of 20 sodium citrate treated samples. The platelet counts of sodium citrate group were higher than that in EDTA-K₂ group (P＜0.05) but were lower than manual counting (P＜0.01). Platelet aggregations disappeared in 17 of 32 patients after adding amikacin into EDTA-K₂ treated whole blood. There were statistical differences between amikacin supplement group and EDTA-K₂ group (P＜0.01). There was statistical differences between amikacin supplement group and manual counting (P＜0.05). The platelet counts in magnesium sulfate supplement group did not show a significant increase within 4 hours. No significant differences were found between magnesium sulfate supplement group and EDTA-K₂group (P＞0.05). The platelet counts of magnesium sulfate supplement group were much lower than manual counting (P＜0.01). The platelet counts in pre-dilution group showed a remarkably increase compared to EDTA-K₂ group (P＜0.01). There were no significant differences in platelet counts between pre dilution and manual counting (P＞0.05).

Sodium citrate anticoagulation and amikacin supplement were not always effective for correcting platelet counts in vitro. Amikacin supplement had better dissociative effects on platelet aggregations than sodium citrate anticoagulation. Magnesium sulfate supplement had a poor dissociation effect on correcting platelet counts. Pre-dilution was the most accurate method. When it is inconvenient to collect peripheral blood from the patient, amikacin supplement is recommended for venous blood.