Tourniquets

Modified on 2009/07/23 11:11 by Ole Losvik — Categorized as: Circulation

We have seen hundreds of mine and war victims with severe limb injuries. They arrive at our clinics nearly dead from bloodloss with tourniquets placed by a relative or health worker in the field. We have also seen those who survived looking with sadness at the short arm or thigh stumps left after surgery. They ask: Why did they have to cut off so much of my leg? The mine wound was down here at my foot!

We have looked at standard books on emergency medicine and found that they recommend tourniquets to stop bleeding from limb injuries. We have seen the tourniquet recommended in ICRC and UN posters. But they are all wrong:

The problem in limb injuries

The victim is dying from oxygen starvation because of blood loss. We need to stop the bleeding to save his life.

The limb is dying from oxygen starvation because it does not get enough blood: At the wound, blood vessels are torn by fragments or the blast wave. Above the wound, arteries are destroyed by the blast wave. The swelling of “the hidden wound” traps muscles and collapses more blood vessels. To save as much as possible of the limb, stop the bleeding and get as much blood into the limb as possible.

There are two ways to do this. Let us compare them
  1. Packing and warming: Lift the limb. Press your hand on the main artery to the limb. Pack gauze or cloth into the wound. Put a tight dressing on the entire limb. Keep the patient warm. The aim of packing and warming is to reduce the blood flow in the injured limb. Pressure on the artery and pressure from the tight dressing make the blood run slower so that clots can form at the bleeding points.
  2. Tourniquet: A rope, leather belt or strip of cloth is tied around the limb and tightened as much as possible. The aim of the tourniquet is to stop blood flow to the injured limb. The theory is that if the tourniquet is tied tight enough, it will block all blood vessels to the limb, both veins and arteries. It will not bleed, but the limb is shut off from the oxygen supply system.

The tourniquet does not work

Bone marrow bleeding. The tourniquet cannot shut off the bloodstream inside the bone marrow. If it takes 6 hours to reach the hospital, lots of blood will be lost. However, if you pack gauze into compound fractures and bone amputations, and keep the patient warm, bleeding from the bone marrow will stop.

The arteries are hidden. The three main arteries below the knee are hidden between the bones (the tibia and fibula). Even the tightest tourniquet cannot block them. Below the elbow, the three main arteries are also hidden between the bones (the radius and ulna), So the tourniquet cannot work here either. Hence, in all injuries to the leg, and even injuries to the foot, the tourniquet must be placed at the thigh. In injuries to the arm, it must be placed above the elbow.

It increases bleeding. Strong adults have a lot of muscles in their thighs and arms, and the main arteries lie deep inside the muscles. A tourniquet made of rope cannot be tied tight enough to squeeze these deep arteries. However, the veins have thin walls and the tourniquet will block the veins. So the arteries which are still partially open pump blood into the injured limb, but the blocked veins cannot drain the blood – and bleeding increases. When the blood pressure has come down to below 90 mm Hg, the body naturally shunts blood away from the limbs. This is when the tourniquet may reduce bleeding. But it is too late! And what happens when you give IV infusions and take the blood pressure up towards normal? The limb starts bleeding again, despite the tourniquet.

Trapping of muscle. Trapped muscle in the amputation stump is a common reason for wound infections, and for cutting off too much of a limb. The trapping is caused by the swelling of muscle damaged by the mine blast wave. Entrapment is common in the muscles of the lower leg and forearm. Tourniquets, blocking the venous drainage from the hidden wound, promote swelling and speed up trapping of muscle. Using tourniquets is asking for entrapment problems.

Blood vessel injury. It injures blood vessels If the victim has had a tight tourniquet for more than 2 hours and you remove it, a disaster happens in the limb: Small arteries and veins become blocked due to a bodily response called re-perfusion damage which is well known by most surgeons. The longer the victim had the tourniquet on, the more the blood vessels become damaged when the tourniquet is removed.

In brief



Stop bleeding – in brief All limb bleeding can be stopped if you lift, press, pack, and put on compressive dressing. Always keep victims warm.

Tourniquets kill limbs, increase bleeding, and only work when the body has lost a lot of blood. That is too late.