Use of Tourniquets
Never has any one subject caused so much debate in First Aid than the use of tourniquets: Whilst it is widely accepted that tourniquets have saved countless lives, their use - especially amongst civilians - is still debated with no consistent guidelines.
The following practices are suggested for use by those with relevant training and experience. As with all of our articles, reading alone does not make anyone proficient in any practical skill.
There is no doubt that tourniquets provide an effective means to stop 'catastrophic haemorrhage' - serious bleeding wounds to the extent that death is imminent due to blood loss. tourniquets are commonly used by the military worldwide, by Emergency Services in the US and - to a lesser extent - in the UK.
There is also, however, evidence to support the negative consequences of inappropriate or prolonged use of tourniquets, including, but not limited to, nerve damage, tissue death and blood clots.
And this is the crux of the argument; tourniquets are effective and appropriate but only if their use is warranted and the person applying the tourniquets understands what they are doing, how to do it and why.
Related article: Duty of Care and The Law
Military versus Civilian settings
UK and US military protocols prescribe the use of tourniquets as the initial treatment for catastrophic haemorrhage:
- The US Tactical Combat Casualty Care - Tactical Field Care guidelines (1) state; 'If not already done, use a CoTCCC-recommended tourniquet to control life-threatening external hemorrhage...'
- UK JSP 999 Clinical Guidelines for Operations (2) state: 'consider tourniquet for catastrophic bleeding'.
Tourniquet use is not without its problems this is why their use must be appropriate; only if necessary and in the correct manner.
Continuous application for longer than 2 hours can result in permanent nerve injury, muscle injury, vascular injury and skin necrosis (3). Muscle damage is nearly complete by 6 hours (4). The majority of these studies are from pneumatic tourniquets applied in elective operations on normovolaemic patients. There are very few studies on hypovolaemic casualties treated with emergency tourniquets.
Reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. The absence of oxygen and nutrients from blood during the ischemic period creates a condition in which the restoration of circulation results in inflammation and oxidative damage through the induction of oxidative stress rather than restoration of normal function.
Compartment syndrome is a serious condition which can affect both life and limb. Raised pressure within the compartment such as the arm, leg or any enclosed space within the body and leads to nerve damage because of the lack of blood supply. Prolonged or inappropriate use of a tourniquet can lead to compartment syndrome, especially if venous blood flow is impeded but not arterial, thereby allowing arterial blood into an area but not allowing venous return.
Tourniquets should be tightened until the distal pulse is no longer felt. (5,6)
A policy of periodic loosening of a tourniquet in an attempt to reduce limb ischaemia has often led to incremental exsanguination and death. (7)
A properly applied tourniquet is painful; a casualty may require significant pain release to apply the tourniquet to the appropriate pressure.
Rationale for Tourniquet use in a civilian setting
Despite the relative low incidence of catastrophic haemorrhage from limb injury in a civilian setting there are occasions where the use of a tourniquet is warranted:
High-hazard settings such as industrial environments experience similar injuries to those seen in hostile environment; principally traumatic amputation and blast injuries.
Mass casualty incidents such as industrial accidents and terrorist attacks result in multiple casualties with serious limb injuries without the resources to treat all casualties with direct pressure.
A casualty with multiple injuries, including serious bleeding limb injuries may be effectively managed by the immediate application of a tourniquet as a temporary measure to stop bleeding whilst Airway and Breathing are assessed and managed. Following successful management of the Airway and Breathing, the tourniquet may be removed under the assessment of Circulation where the bleeding wounds may be more appropriately treated with more basic measures.
Where a casualty is trapped and direct pressure may not be applied to the limb injury because of lack of access a tourniquet may be appropriate as the only remaining method of controlling the bleed.
The risks of hypovolaemic shock greatly outweigh the potential damage to the limb beyond the point of tourniquet application in the case of an amputation.
Principles of Tourniquet Application
If it is deemed necessary to apply a tourniquet either because the necessity of the situation dictates or because the simple measures are not sufficient; it is imperative that the tourniquet is applied appropriately.
- Use a dedicated tourniquet - improvised tourniquets often time too long to fabricate and their inefficiency can lead to an increased risk of complications. The US Dept of Defence Committee of Tactical Combat Casualty Care (8) advocate the use of the Combat Application Tourniquet.
- The tourniquet should be applied onto bare skin to prevent slipping.
- Single and double bone compartments:
Traditional teaching has avoided placement of a tourniquet over a double bone compartment (lower leg or lower arm) as the twin bones in these areas may protect the blood vessels from adequate compression from a tourniquet. Although there is little evidence to contradict this theory, recent anecdotal evidence from Iraq and Afghanistan challenge it. (9)
- Tighten the strap fully before tightening the windlass.
- Write the Time and Date on the tourniquet and mark the casualty with a T on their cheek (easier to see than on the forehead if they are wearing a helmet and more likely to remain clear because of less sweat).
The time and date of the tourniquet application should be mentioned in the communication and handover. Any casualty who has a tourniquet applied is classed a "1 - Immediate" on any triage sieve.
There is conflicting information in tourniquet placement:
- Lee et al (10) advocate “…placement of the tourniquet as distal as possible, but at least 5 cm proximal to injury; sparing joints as much as possible. If it is ineffective…the health care provider may consider a second tourniquet placed just proximal to the first. (p.586)
- RCS Faculty of Pre Hospital Care (9) state “The first is mid point (if possible) over a single bone and if bleeding is not controlled, then the second tourniquet is sited just below this. The distal one will effectively be in a lower pressure zone.”
“If the wound is to a distal part of the limb [lower limb injury] and blood loss is well controlled then consideration should be given to the application of a second tourniquet about two inches proximal to the edge of this wound”
- JRCALC Guidelines (11) state “Apply the tourniquet on the limb over a single bone compartment as close to the joint as is practical” If bleeding is uncontrolled “Apply a second tourniquet just below the first”. (p.205) This is clearly contradictory.
- The 1st tourniquet always goes on an upper part of the limb - on the thigh or upper arm. These are single-bone compartments where the blood vessels can be effectively compressed against bone.
- The tourniquet is placed as low down as possible - close to the wound or just above the joint - to preserve as much healthy tissue as possible.
- If a 2nd tourniquet is needed, this is placed above the 1st.
- A second tourniquet can be applied above the first or at the end of the limb. A double-bone compartment (lower leg or forearm) is not the most effective place for a tourniquet as some of the blood vessels are protected from compression between the bones. It is now thought that if a 2nd tourniquet is needed it can go just above the wound in an extremity amputation as the blood pressure will already be vastly reduced following the application of the first tourniquet higher up the limb.
Releasing the Tourniquet
If the civilian First Aider has applied a tourniquet as an interim measure due to multiple injuries or because of limited resources, there may be merit in 'downgrading' the treatment for serious bleeding under Circulation of the ABC protocol or once the situation has been managed, other injuries have been stabilised or after additional resources have been sourced.
Releasing the tourniquet once the casualty has been stabilised will, theoretically, avoid or limit the complications of prolonged use of a tourniquet, listed above.
Alternatively, after a period of time of reduced arterial flow from tourniquet use, clotting may have occurred sufficiently, allowing simpler methods of haemorrhage control to be effective
The argument against removing a tourniquet once applied is that it may:
- increase blood pressure and perfusion into the limb which may disturb the clot which is forming at the site of the injury, causing further bleeding or
- releasing toxins into the circulatory system which have built up in the injured limb beyond the site of the tourniquet - rhabdomyolysis.
The tourniquet should remain in place if (10):
- The transit time to definitive care is less than one hour.
- The casualty has other life threatening injuries.
- The casualty has unstable vital signs.
Before release of the tourniquet secure wound packing / haemostatic and application of direct pressure.
If careful release of the tourniquet then results in a return of uncontrollable external haemorrhage, the tourniquet should be replaced and not removed until the patient is in the operating theatre.
Military medics and Emergency Services personnel should follow their current protocols regarding the release of tourniquets.
Tourniquets are an effective method of controlling serious bleeding which may not otherwise be controlled by simple measures but only if applied effectively.
The use of tourniquets includes serious complications especially if applied inappropriately or for extended periods of time.
- Catastrophic Bleeding: In all military situations a tourniquet is proposed as the initial treatment. In a civilian setting this is not openly or universally directed but where appropriate this could be applied in the first instance. After Airway and Breathing have been managed and upon reassessment of bleeding wounds under Circulation, the tourniquet may be able to be replaced by simpler means.
- Non-Catastrophic Bleeding: tourniquets form part of a hierarchical approach to treating all bleeding wounds which may not controlled by simpler means.
- 1st tourniquet always goes as low down an upper part of the limb as possible - above the wound or above the joint.
- The 2nd tourniquet is placed just above the first. If an extremity amputation, the 2nd tourniquet can be placed just above the wound.
- The tourniquet is tightened with the aim of stopping a distal pulse.
- The casualty is clearly marked including time and date. This is clearly communicated at handover and the casualty is elevated to "Immediate" in triage.
- The casualty DOES NOT have an amputation and
- Dangers at the scene have been stabilised and
- Bleeding has stopped and
- The casualty’s vital signs are normal and stable and
- Transfer time to definitive care is greater than one hour
Method of removal:
- Before release of the tourniquet secure wound packing / haemostatic and apply direct pressure.
- If careful release of the tourniquet then results in a return of uncontrollable external haemorrhage, the tourniquet should be replaced and not removed until the patient is in the operating theatre.
- Bellamy RF. "Combat trauma overview". In: Zajtchuk R, Grande CM, eds. (2005) Textbook of military medicine part IV: surgical combat casualty care. Office of the Surgeon General, US Army.
- Lakstein D, Blumenfield A, Sokolov T, et al. (2003) "Tourniquets for hemorrhage control on the battlefield: a 4 year accumulated experience." Journal of Trauma. 54(5 Suppl):S221–5.
- Clifford CC. (2004) "Treating traumatic bleeding in a combat setting." Military Medicine. 169(12 Suppl):8–10.
Faculty of Pre Hospital Care (2015) “Interim position statement on the Site of application of Tourniquets” Royal College of Surgeons.
- Lee, C. Porter, K.M. and Hodgetts, T.J. (2007) "Tourniquet use in the civilian prehospital setting". Emergency Medical Journal. 24:8 584-587
- Joint Royal Colleges Ambulance Liaison Committee. (2015). UK Ambulance Service Clinical Practice Guidelines. Warwick: JRCALC