止血带不应扎得太紧，使用时间应尽量缩短。抽血时，见到回血应立即松开止血带，减少血行阻滞时间(也不应鼓励被抽血者长时间、用力攥拳)。
Tourniquets should not be tied too tightly, and the use time should be shortened as much as possible. When drawing blood, the tourniquet should be loosened immediately to reduce the time of blood block (and the person who is drawn should not be encouraged to hold the fist for a long time).
(1)血脂项目、凝血项目、血常规项目抽血时止血带使用应限定在1分钟以内。
(1) the use of tourniquet should be limited to within 1 minute when taking blood from blood lipid items, coagulation items and blood routine items.
(2)止血带束缚太紧、时间过长(如超过3分钟)，会造成血行阻滞时间过长，因溶血、血小板激活、纤溶系统激活等原因将使以上检验项目的结果产生偏差，甚至诱导错误诊治。
(2) the tourniquet binding is too tight and the time is too long (if more than 3 minutes), which will cause the blood block time to be too long. Due to hemolysis, platelet activation, fibrinolysis system activation and other reasons, the results of the above test items will be biased, and even lead to wrong diagnosis and treatment.
(3)需要重新采血时，在止血带束缚时间太长的情况下，应当在对侧手臂重新采血。
(3) when it is necessary to take blood again, when the tourniquet binding time is too long, the blood should be taken again in the opposite arm.