What Is a Tourniquet?

Tourniquete is a medical device specially designed for emergency hemorrhage control. By applying strong compression to the proximal end of an injured limb (the end closer to the torso), it mechanically blocks arterial bleeding. It is typically used in cases of severe trauma with massive bleeding that cannot be controlled by direct pressure.

Its core function is to temporarily prevent blood loss and buy time for subsequent medical rescue especially critical in battlefield first aid, natural disasters, or accident scenes.

Tourniquets are usually made of high-strength medical materials; unlike improvised substitutes (such as belts or strips of cloth), they allow precise control of applied pressure to minimize the risk of tissue damage.

Common materials used in tourniquets include:

● Hook-and-loop straps or inflatable cuffs—to provide rapid fixation and maintain stable pressure

● Ratchet or windlass locking mechanisms—to achieve progressive tightening and prevent slippage

● High-elasticity silicone/rubber bands—for both extensibility and tensile strength, distributing pressure evenly when wrapped

● Nylon webbing base—as the main load-bearing component, meeting waterproof, tear-resistant, battlefield-grade durability standards

When Should a Tourniquet Be Used?

Life-threatening hemorrhage

Consider a tourniquet when bleeding spurts or flows uncontrollably, or when 10 minutes of direct pressure fails to stop it. Such situations commonly involve deep arterial injuries in the neck, axilla, or groin, where blood loss can induce shock within minutes.

Amputation or large open wounds

When a limb is partially or completely severed, muscle tissue is exposed, and blood vessels are transected, a conventional pressure dressing cannot cover the wound. A tourniquet must be applied 5-7 cm proximal (toward the heart) to the injury to control bleeding.

Multiple casualties in high-risk environments

In battlefield, explosion, or major traffic accident scenarios with multiple wounded and limited resources, a tourniquet can quickly stop bleeding, ensuring patient survival and buying time for medical teams to triage.

Different Types of Tourniquets

1. By Intended Use

Military Tourniquet

· CAT (Combat Application Tourniquet): Integrated plastic ratchet design allows single-handed rapid tightening; webbing is tear-resistant—suitable for mid-limb application on arms or legs.

· SOF-T (Special Operations Forces Tourniquet): Steel windlass with elastic webbing; non-elastic base reduces slippage—can be applied proximally on thigh or under the axilla where tension is high.

· SAM-XT: Adjustable width, suitable for pediatric patients or those with slender limbs.

Medical Tourniquet

· Venous tourniquet for infusion or phlebotomy: Temporarily occlude superficial veins, typically made of latex or TPE; gentle constriction without pain.

· Surgical tourniquet: Pneumatic cuff with pressure regulator to ensure a clear surgical field, some include sensors to prevent prolonged ischemia.

· Obstetric-gynecologic tourniquet: Specialized pneumatic devices to control massive uterine bleeding, precisely conform to pelvic vascular anatomy.

Outdoor/Sports Emergency Tourniquet

Improvised using backpack straps, triangular bandage, etc., paired with a rigid windlass (e.g., a stick or pen). Folding tactical tourniquet substitutes are common in mountaineering packs.

2. By Usage Characteristics

· Disposable tourniquet: Prevent cross-infection, common in routine hospital procedures; low-cost and easy to discard.

· Reusable tourniquet: Typically silicone or nylon, resistant to aging and disinfectants; require periodic inspection for elasticity and wear.

3. By Structure and Fastening Method

· Velcro tourniquet: Rapid adhesion, suitable for one-handed operation, though adhesion may weaken when cold or wet.

· Buckle-type tourniquet: Metal hook-lock reinforcement, robust in battlefield conditions, operable with gloves.

· Pneumatic tourniquet: Inflatable cuff with pressure gauge, used to exsanguinate limbs before surgery, surgical-grade products require pressure error < 10 mmHg.

4. By Material

· Latex rubber tourniquet: High resilience but may cause allergies, prolonged use can adhere to skin.

· TPE tourniquet: Good biocompatibility, soft and non-irritating—ideal for children or sensitive skin.

· Silicone tourniquet: Heat-and corrosion-resistant; autoclavable at 121 °C for repeated use.

· Nylon webbing tourniquet: Military-spec durability; remains tough at -40 °C.

How to Use a Tourniquet

1.Assess the situation

Deploy a tourniquet only for arterial bleeding—bright red, spurting blood unresponsive to direct pressure. Prioritize injuries in the neck, groin, or other areas where direct compression is ineffective.

2.Position the tourniquet

Place it at least 5-8 cm proximal to the bleeding site, avoiding joints or bony prominences. If the wound is near a joint, position the tourniquet above the joint.

3.Tighten the tourniquet

Standard tourniquet: Pull the strap evenly until the distal pulse disappears or bleeding stops.

Military tourniquet: Wind the ratchet or windlass until it can no longer turn, or the windlass locks fully.

Complete this step within 15 seconds; the patient may experience severe pain—do not loosen.

4.Secure the tourniquet

Fasten the strap end with hook-and-loop or buckle; ensure the ratchet or windlass cannot shift.

Mark the time of application on the patient's forehead or adjacent to the tourniquet with a marker.

5.Monitor the casualty

Every 10-15 minutes, check the distal limb for cyanosis or worsening swelling. Do not cover the tourniquet or conceal it with clothing.

Under non-extreme conditions, limit tourniquet use to 2 hours (up to 4 hours in cold environments).

6.Obtain emergency assistance

Contact EMS immediately, specifying tourniquet application time and patient response.

If transport exceeds 1 hour, trained medical personnel should evaluate the need for intermittent loosening.

How to Choose the Right Tourniquet

Consider training level

Untrained users: Choose color-coded, text-guided clamp-style tourniquets (e.g., SAM-XT) to avoid complex manual windlass operation.

Regularly trained users: Prefer military-grade windlass models (e.g., CAT Gen7 or SOF-T Wide) for single-handed rapid locking and higher load capacity.

Assess risk environment

High-risk settings (battlefield, wilderness): Carry two NATO-certified tourniquets, at least one with night-reflective stripes.

Everyday first-aid kit: Choose a wide elastic model that also supports fracture stabilization; avoid narrow straps that may cut into skin.

Cost considerations

Basic models: Rubber or nylon buckle types—suitable for short-term emergencies but require replacement every six months.

Professional models: Full-metal ratchet systems (CAT series)—tear-resistant with a service life over five years.

Quality assurance

Certifications: Surgical tourniquets should bear FDA or CE marks; tactical models should comply with TCCC guidelines.

Strength testing: Genuine products can suspend 100 kg for 30 seconds without deformation; stitching should be smooth.

Authorized channels: Verify dealers via military-partner brand websites; beware of "loose" packaging without seals.

When Not to Use a Tourniquet

Minor bleeding

For oozing or slow seepage that only soaks through half a gauze pad, apply direct palm pressure for 10 minutes—tourniquets may tear tissue and worsen injury.

Unclear bleeding type

For dark, slow venous bleeding or capillary ooze (abrasions), use an elastic bandage. Misapplication of a tourniquet can lead to repeated seepage and delayed care.

Constrained locations

Gunshot wounds to the neck, groin, or torso cannot be effectively controlled by a limb tourniquet; forcing one may compress airway or organs. Use hemostatic dressings instead.

Severely mangled limbs

Irregular amputations or exposed bone shards prevent even pressure; consider vascular clamps or hemostatic powder.

Excessive time risk

If professional help is more than 2 hours away (e.g., remote mountain areas), continuous tourniquet use risks limb necrosis. Instead, use local pressure with limb elevation.

Specific contraindications

· Tourniquet on frostbitten or burned tissue may strip skin.

· Diabetic patients with poor circulation risk nerve damage after 30 minutes of application.

· After venomous snakebite, tourniquets may concentrate toxin; use suction and topical agents instead.