How to use the tourniquet

 The use of tourniquets is relatively simple, but the principles of use are more complicated. Only by accurately mastering these principles can we save lives and limbs, otherwise it will lead to amputation and disability.

1. Before the upper tourniquet, the injured limb should be raised first, so that the venous blood flows back to the body, thereby reducing blood loss.

2. The position of the upper tourniquet should be as close as possible to the bleeding site under the premise of effective hemostasis. However, the use of a tourniquet is forbidden in the middle of the upper arm, because the phrenic nerve passes through the surface of the tibia, and the compression of the tourniquet can cause damage to the phrenic nerve, which makes the function below the forearm difficult to recover in the future.

3. The tourniquet can not be directly tied to the limb. The area where the tourniquet is prepared should be padded with a soft cloth pad such as a dressing or towel to protect the skin.

4. When using a cloth or a handkerchief to make a cloth-like tourniquet, you should first stack it into a strip, about 5 cm wide, so that the force is even. It is strictly forbidden to use ultra-thin and inelastic items such as wires, wires, and strings as a tourniquet, because these items not only have an unsatisfactory hemostasis effect but also damage the skin, causing trouble for future treatment and rehabilitation.

5. When the hemostasis is tied, the tightness of the tourniquet should be just to suppress the bleeding of the artery. The upper belt is too tight to cause damage to the skin, nerves, blood vessels and muscles at the tourniquet, and even causes necrosis at the distal end of the limb, which is not conducive to the functional recovery of the injured limb in the future; the upper belt is too compressed to press the vein without pressing the artery. Blood can only go out, not only can not achieve the purpose of stopping bleeding, but it will aggravate bleeding. The criteria for success in the upper zone are that the distal arterial bleeding stops, the arterial pulsation disappears, and the extremities become white.

6. The wounded on the upper tourniquet should be clearly marked and clearly marked with time on or near the tourniquet. In order to prevent ischemic necrosis of the injured limb, relax the tourniquet for 1 to 2 minutes every 40 to 60 minutes. The action should be slow when loosening the belt, and the need to press the wound to reduce bleeding. If the injured person has poor general condition, a large wound, and a large amount of bleeding, the time interval for relaxing the tourniquet can be appropriately extended. However, the total time of the tourniquet should not exceed 5 hours, otherwise the distal limb is difficult to survive. If the injured person is still on the way to the hospital for more than 9 hours, then the tourniquet will not be relaxed at this time because the distal limb has no survival. Necrotic cells release toxic substances such as potassium ions, myoglobin and peptides. If the limbs are loosened at this time, these toxic substances will flow into the body with the veins, causing poisoning, which can lead to sudden cardiac arrest and sudden death. In the same way as this, in the first-aid of the earthquake-stricken area, if the wounded limb is buried for too long, tissue necrosis has occurred due to ischemia and hypoxia. To prevent the toxin from returning to the whole body, the limb should be quickly ligated with a tourniquet. Then remove the pressed object and send it to the hospital for further processing.