1、扎止血带的部位为穿刺点上方10厘米。距离太远，静脉充盈不好，太紧可造成血管破裂。
1. The location of the tourniquet is 10 centimeters above the puncture point. The distance is too far, the vein is not good enough, too tight can cause the blood vessel to break.
2、第一次消毒后在待干间隙扎止血带，进行第二次消毒后、待干、穿刺。扎止血带时间为40-100秒，松紧以一指为宜。时间大于120秒使静脉过度膨胀、挛缩，影响穿刺成功率。
2, after the first disinfection, the tourniquet was dried at the interval to dry, after second disinfection, dry and puncture. The time of tourniquet is 40-100 seconds. Over 120 seconds, the vein overexpanded and contracted, which affected the success rate of puncture.
3、见回血后，先松解止血带后固定。
3. After seeing the blood, loose the tourniquet before fixing it.