sodium citrate and blood collection tubes

Blood collection tubes (blue-headed tubes) containing sodium citrate anticoagulant at a concentration of 3.2% (0.109 mol/L): sodium citrate acts as an anticoagulant by chelating calcium ions in the blood sample, and is available for most coagulation tests Sodium citrate anticoagulation, it contributes to the stabilization of factors V and VIII. In addition, the activated partial thromboplastin time (APTT) test using sodium citrate anticoagulated plasma is much more sensitive to heparin than oxalate anticoagulated plasma, when the APTT test is used to monitor patients receiving heparin therapy. This is very important in patients. Only 6 mg of sodium citrate can anticoagulate 1ml of blood. It is highly alkaline and is not suitable for blood tests or biochemical tests. Sodium citrate has little effect on MPV and other coagulation factors, and can be used for platelet function analysis.The aggregation of platelets increases with the decrease of the concentration of sodium citrate in plasma, so more anticoagulants should be added in patients with anemia than normal people. For blood coagulation tests, if the blood ratio is too low, the APTT time will be prolonged and the prothrombin time (PT) results will be significantly changed. PT determination, 3.8% of the anticoagulant was higher than the 3.2% international normalized ratio (INR) value, and the difference was generally between 0.7 and 2.7 INR units. Due to the low toxicity of sodium citrate, it is also used for blood preservation. At the same time, sodium citrate dissolves slowly in water, so it can only be formulated into a water solution instead of a powder. When the ratio of anticoagulant to blood is 1:9, it is mainly used in the fibrinolytic system (prothrombin time, thrombin time, activated partial thrombin time, fibrinogen). When collecting blood, pay attention to the amount of blood collected to ensure the accuracy of the test results. Immediately after blood collection, it should be inverted and mixed 5-8 times.