II. Indications: Extremity Hemorrhage
- Indicated for rapid extremity bleeding not controlled with direct manual pressure
III. Precautions
- Tourniquets are a last resort when rapid bleeding cannot be controlled with direct manual pressure
- Tourniquets can be life saving but have significant risks associated with use (see below)
- Temporizing only until surgical intervention within 1-2 hours
- Tighten Tourniquet enough to obstruct both venous and arterial flow
- Otherwise, increased risk of venous Tourniquet (with continued bleeding, Compartment Syndrome)
IV. Preparations
- Pneumatic Tourniquet (92% effective)
- Cuff (3.5 inch wide) is inflated in similar fashion to Blood Pressure cuff
- Inflate to minimum pressure needed to control active bleeding
- Windlass Tourniquet (79% effective)
- Strap tightened by winding a rod
- Apply Tourniquet and rotate the windlass 1-2 complete turns until arterial bleeding stops
- Improvised Tourniquet (67% effective)
- Use A band of fabric at least 3 inches wide
- Wrap the band snugly around the limb and tie a half knot
- Insert a rigid cylinder (metal bar or stick) as a windlass above the half knot
- Tie a full knot over the cylinder
- Rotate the cylinder 1-2 complete turns until arterial bleeding stops
- Secure the cylinder in its rotation
- Risk of secondary injury due to sharp edges on improvised devices
- Unevenly distributed pressure with lower efficacy than professionally produced Tourniquets
- Replace improvised Tourniquet with professionally produced Tourniquets as soon as available
- Use A band of fabric at least 3 inches wide
V. Protocol
- Notify Trauma surgery of emergent surgical intervention for rapid, uncontrolled bleeding
- Apply Tourniquet to appropriate site
- Avoid applying over the top of wounds of in junctional locations (see contraindications below)
- Apply directly to skin (without interceding clothing or material)
- Apply 2-3 inches above any wound and 2-3 inches above a joint
- Mark time of application on Tourniquet and on easily visualized tag
- Two side-by-side Tourniquets may be applied if one is insufficient
- Wider Tourniquets are more effective than 2 single Tourniquets
- Two Tourniquets should be applied immediately adjacent without a gap
- Gap between Tourniquets creates a localized Compartment Syndrome
- Tourniquet should remain in plain site and never covered
- Tourniquet up-time should be reviewed frequently
- Conscious patients should be asked to remind providers of Tourniquet's presence
- Prolonged Tourniquet (delayed intervention or transport)
- Consider deflation intervals every 30 minutes (unclear efficacy in limb salvage)
- Reposition Tourniquet closer to bleeding site (if initial one is too proximal)
- Apply a second Tourniquet loosely 2-3 cm above the wound
- Release first Tourniquet and observe for recurrent uncontrolled arterial bleeding
- If bleeding persists, tighten the new, most distal Tourniquet
- If bleeding still persists, re-tighten the initial proximal Tourniquet without a gap between 2 Tourniquets
VI. Contraindications
- Obviously unusable at the neck and trunk
- Ineffective in junctional sites (e.g. axilla, groin)
- Ineffective at adductor canal (Hunter canal)
- Canal runs through medial aspect of the distal one-third of the thigh
- Carries femoral artery, femoral vein and femoral nerve
VII. Adverse Effects
- Metabolic disturbance (local accumulation with systemic release)
- Lactic Acidosis
- Hyperkalemia
- Increased Creatinine phospokinase (CPK) with Renal Failure risk
- Local injury
- Peripheral Nerve palsy
- Post-Tourniquet Syndrome
- Extremity ischemia, infarction, necrosis and gangrene
- Tourniquet for 1 hour: Safe without significant longterm complications
- Tourniquet for >2 hours: Significantly increased risk of longterm sequelae
- Tourniquet for >3 hours: Amputation required in >62% of cases
- Tourniquet for >6 hours: Amputation required in 100% of cases
VIII. Efficacy
- Tourniquet application has resulted in dramatic mortality benefit (96% vs 4% survival)
- Tourniquet effectiveness in relation to limb circumference
IX. References
- McCollum and Knight (2023) EM:Rap 23(9)
- Swaminathan and van de Leuv (2013) Crit Dec in Emerg Med 27(8): 11-17
- Kragh (2008) J Trauma 64(2 suppl): S38-49 [PubMed]