Medicine for the Outdoors
Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.See all posts »
Using a Tourniquet
Tourniquets have been a staple of emergency field care for centuries. The usual application of a constriction bandage to staunch the flow of bleeding is an emergency maneuver that takes the risk of losing a limb (from loss of circulation) in order to save a life. Other uses for constriction bandages generally involve severe envenomations, such as from venomous snakes or marine animals, in order to impede the distribution of life-threatening venom.
Again, a tourniquet is indicated only in a life-threatening situation and is best applied by an experienced person. Only in the case of torrential bleeding is a tourniquet more advantageous than continuous pressure, because pressure properly applied is very useful. The decision to apply a tourniquet is one in which a limb (hand, foot, arm, or leg) might be sacrificed to save a life.
A tourniquet should be applied to the limb between the bleeding site and the heart, as close to the injury as is effective to control the bleeding. The reason for placing it close to the bleeding is to preserve as much living tissue (which is "above" the tourniquet) as possible. The tourniquet should be tightened just to the point where the bleeding can be controlled with direct pressure over the wound. If you must leave the victim after applying a tourniquet, and therefore can no longer apply direct pressure, be certain to check that it is still effective after you have released pressure.
To construct a tourniquet, use a 2 to 4 inch (5 to 10 centimeter) bandage — not something thin (like a string, wire, or electric cord) that might cut through the skin. Wrap the bandage around the limb several times, then tie half or an entire square knot, leaving loose ends long enough to tie another knot on top of the first knot (as part of the next step). The next step is to place a stick or stiff rod over the first knot, then tie it firmly in place with the loose ends. Twist the stick until the bandage is tight enough to stop the bleeding, then secure it in place with another cloth, tape, or circular bandage.
If possible, the tourniquet should be loosened or released briefly every 10 minutes to see if it is still necessary. Some authorities recommend loosening it after 5 minutes, which might be all right if the bleeding is not torrential. If the bleeding can now be controlled with direct pressure, don't re-tighten the tourniquet, but keep a very close watch on the situation. If the original wound damaged or severed a very large blood vessel, it is likely that you will need to keep the tourniquet in place for more than 10 minutes. Always keep a tourniquet in plain view, so that it doesn’t get left in place longer than necessary just because someone didn’t know or forgot it was there.
For the benefit of EMS (emergency medical services providers, such as EMTs [emergency medical technicians] or paramedics), the question arises whether a tourniquet should be loosened prior to establishment of an intravenous (IV) line and fluid administration. I believe the guidelines above should suffice. If a person is in a very precarious position with respect to hemorrhage (low blood pressure or shock), then I would err on the side of caution and resuscitate with fluid prior to releasing the tourniquet. On the other hand, if the patient was "stable" (reasonable blood pressure, normal mental status, etc.), and I might save the limb by loosening the tourniquet, I might opt to follow that pathway. It is a judgement call made at the scene by someone willing to accept responsibility for the outcome.
Tags: tourniquet, bleeding, hemorrhage, physician, health, wilderness medicine, outdoor medicine, healthline
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