Garrot

This article relates to the First aid, and the gestures to stop a Hémorragie.

---- First aid > Gestures of first urgency > Garrot ----

The garrot is a gesture intended to stop a Hémorragie of a member when no other method is effective. The technique consists in compressing the Artère of the member against the bone by using a broad bond of fabrics and nonelastic , it is a method known as of “remote compression”.

The installation of the garrot is not possible that with the arm (between the shoulder and the elbow) for the hemorrhages with the upper limb, and on the thigh (between the hip and the knee) for the hemorrhages with the lower extremity. It is important to note the hour of installation of the garrot on a paper pinned with clothing of the victim (this information will be invaluable for the medical team).

Why is it essential to note the hour of installation of a garrot?

During the installation of a garrot, one stops blood circulation in order to stop the hemorrhage. However the cells contain in their intracellular liquid, a concentration of K⁺ ions more important than in the extracellular medium, thus causing a gradient of K⁺ which leave in great number. This is explained in the following way:

potential of balance of the ion K⁺:

$E (K^+) = \ frac {R \ times T} {z^F} \ times ln \ left (\ frac {_ {extracellular}} {_ {intracellular}} \ right)$

Z being the load, F the number of Faraday, T the temperature, R a constant and concentration of K⁺

potential of membrane of the cell:

$VM = \ frac {G (Na) \ times E (Na) + G (K) \ times E (K)}{G (Na) + G (K)}$

G being the Conductance and the presence of Na being explained by the fact that both Cations being exchanged in the cell are Na and K, Na entering and K outgoing.

One thus notices that however extracellular increases, as in the case of a garrot since this ion cannot circulate. The danger is thus if one removes the garrot after 20 min i.e. time when K⁺ accumulated in a very strong way in the extracellular liquid. The increase in the concentration of K⁺ outside the cells will involve an increase in E (K) (cf formulates Ci above) and the latter involving an increase in VM (cf formulates). What will have for consequence, a balance of the ion K⁺ on both sides of the cellular membrane and thus an exit of the cell towards the outside less important of K⁺. However the exit of these ions have a big role in the repolarization of the cardiac cell. The less exit of K⁺ by balance on both sides of the membrane involves an effective repolarization month, a loss of Potentiel of action and thus the Cardiac arrest .

When the bleeding authorizes a point of compression, it is preferable with the garrot if the helps were to arrive after 20min. In a situation where the garrot is essential for the stop of the bleeding, this last will be withdrawn by the medical community only which, while simplifying, will gently loosen the garrot to allow a progressive irriguation of the private bodies in order to control the flow of K⁺ going up in the middle in order to preventing a stop cardic. an cardiac arrest caused by the K⁺ ions is irreversible!!

When is a garrot posed?

A garrot must be posed on a member who bleeds abundantly, after the protection, when one cannot stop the hemorrhage in another manner. The typical cases are:

the other techniques (direct manual support or Not of compression) appeared ineffective or impossible to realize, for example:

hemorrhage of the lower extremity on a person sitting in a vehicle,
direct compression is not possible (the wound is too large, or inaccessible, or there is an object planted inside), and the point of compression is ineffective;

the rescuer stopped the hemorrhage with a point of compression, but it must forsake the victim to deal with another vital distress or to go to prevent the helps; one will then pose the garrot before to slacken the point of compression;
the rescuer is vis-a-vis many victims, it parre urgently and poses a garrot in first intention to be able to deal as soon as possible with the others.

In the event of bite by a snake for example, one should not put garrot, as opposed to what many people believe.

Polemic around the garrot

The appropriateness of the installation of the garrot is evaluated in a different way according to the countries. The two extremes are represented by the the United States and the France:

in the United States, the gesture is reserved to the professional first-aid workers ( paramedics ), and only in the cases of extreme urgency (many victims or unverifiable hemorrhage even with a clamp ); the loss of the member is regarded as a main risk, and in particular a legal risk (risk to be continued by the victim or its family);
in France, the gesture is taught with the general public, the loss of the member is regarded as having little risk to occur (being given the speed of the helps), and it is the risk of death per hemorrhage which precedes; gesture is regarded as proportioned with risk and it is not very probable that continuations succeed (even if risk zero does not exist), the loss of the member being initially charged to the wound before being charged to the saving action.

Case of France

During many years, one said “the garrot must be absolutely avoided, there is a risk to lose the member” and “the garrot must be loosened every half-hour in order to continue to irrigate the member”. One in addition found garrots elastic in the cases of help.

One has since 1991 a completely different approach. Now, the installation of the garrot is a technique of stop of the hemorrhages like another, it is done with a nonelastic bond, and it should not be loosened under any pretext, for the following reasons.

The risk to lose the member is real, but occurs at the end of 6 H; in France, the victim will have been taken of load for a long time. In addition, medicine made progress, one can now react to toxins released by the death of the cells (Rhabdomyolyse, Syndrome of buried the known as “of Bywater”). On the other hand, not to pose a garrot can involve the Mort victim! The benefit ratio/risk leans clearly in favor of the installation of the garrot.

Concerning the elastic garrot: it is used at the time of the blood tests or for the injections, are role is to support the flow of blood, not to stop it…

So now one loosens the garrot, blood will flow towards the wounded member. However, this one being private of oxygen contribution, the muscles vasoconstricteurs, which limit circulation in the blood-vessels, are completely slackened (Vasodilatation), and a certain number of vessels are empty of blood. A great quantity of blood thus will pass from the remainder of the body in the member, which abruptly will make fall the pressure of blood on the level of the heart, and is likely to drain the cardiac pump (Hypovolémie relative). To loosen the garrot can thus cause in oneself a stop of circulation! In addition, that will make take again the bleeding (loss additional of blood), and the cells of the member being in deficit of dioxygene and in carbon dioxide excess, blood will set out again of member very low in dioxygene and very rich in carbon dioxide, which will involve on the one hand an acceleration of ventilation (to eliminate CO₂ and to bring of O₂), and on the other hand an acidosis of blood (reduction in pH).

The concept to loosen the garrot is sometimes taught in the countries where the structure of the helps does not allow a fast assumption of responsibility of the victim. This is completely out of matter in France, the people travelling in these countries are invited to require council of a doctor.

The guiding line in France given by the reforms of 1991 and 2001 are clear: one should not hesitate to pose a garrot so necessary, which will be a nonelastic broad bond and which must be maintained tight.

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