EMS Recap: Tourniquets

A tourniquet could be the difference between whether a patient with extremity hemorrhaging lives or dies

Today, medics involved in tactical operations, mass casualty events, disasters or working in rural communities should consider the tourniquet as another method to prevent extremity exsanguinations.1 Tactical operations, disasters and mass casualty events offer medics performing triage in the prehospital environment opportunities to use tourniquets to save more lives during that first round of triage. Tourniquets should be considered another treatment modality and not a treatment of last resort.2 Applying a tourniquet to stop a severely bleeding extremity wound3 in the prehospital environment prior to the onset of poor perfusion is associated with positive patient outcomes.4

Tourniquet Application

Elimination of distal artery flow is the primary purpose of a tourniquet. Any tourniquet that cannot stop arterial flow is not effective.1 One precursor to the tourniquet was the use of tight bandages placed proximal to the point of surgical amputation.5 Most commercially manufactured tourniquets are designed for quick application, usually within 60 seconds. A tourniquet replaces the need for direct pressure, additional bandages or a second care provider during transport. A properly trained medic should be able to effectively stop extremity hemorrhage, accomplish multiple interventions and initiate immediate transport without the need for additional responders.2

Currently, most medics are trained to place the tourniquet just above the sight of the injury while avoiding placement over a joint. Placing the tourniquet more proximally to the injury on the thickest portion of the extremity helps to limit damage to the underlying tissue and prevent any minor bleeds near the injury.2 Once positioned, tourniquet tightness requirements will increase with the size of the limb. There is an inverse relationship between the width of the tourniquet and the pressure needed to halt arterial blood flow. Complete occlusion of arterial flow on the lower extremities is extremely difficult, if not impossible, with a one inch wide tourniquet. A wide tourniquet will be more effective on a lower extremity, as there is less pressure needed on the greater surface area to successfully occlude arterial blood flow, and less tissue damage will occur.1

The original strap tourniquets and their manufacturers were not subject to FDA testing and approval as of 2005, so the military developed minimum effectiveness standards for testing. All military tourniquets must achieve distal artery occlusion for thigh applications at least 80% of the time to be considered effective. Testing revealed the need for a windlass or another type of mechanical advantage to effectively tighten the tourniquet.1

You should be reluctant to use an improvised tourniquet, as most of them will not be effective at occluding arterial blood flow. If an improvised tourniquet is the difference between your patient living or dying, the best improvised tourniquet in your arsenal is the manual blood pressure cuff.2 Regardless of the type of tourniquet used, once applied, do not remove it if the patient is in shock, the limb was amputated, there are obvious arterial disruptions, the tourniquet has been on for an extended period, or you will be transferring care and can no longer observe the patient.3 The tourniquet may need to be tightened after initial application as the arterial pressure increases from sympathetic nervous system response to pain and injury or air has leaked from the manual blood pressure cuff.6

Two hours is considered the length of time a tourniquet can be in place before neuromuscular injury and functional loss begin. For applications longer than 2 hours, cooling the limb may help delay injury and loss of function. The best method to save a limb is rapid transport and converting to a less-damaging means of hemorrhage control as soon as practicable.3

This content continues onto the next page...