What is exsanguination?

What is Exsanguination

Exsanguination is severe, life-threatening blood loss that leads to circulatory collapse and death if not immediately controlled. 1, 2

Definition and Clinical Characteristics

Exsanguination represents a critical state of hemorrhagic shock where blood loss overwhelms the body's compensatory mechanisms. The term specifically describes:

• Massive hemorrhage causing profound hypotension unresponsive to rapid crystalloid infusion or sudden hemodynamic deterioration 1
• Blood loss requiring massive transfusion, typically defined as needing ≥10 units of packed red blood cells within 24 hours or ≥1,500 mL during initial resuscitation 3
• Estimated blood loss exceeding 2,000 mL during trauma operations 3
• Bleeding rate >15 mL/minute that predicts mortality 3

Physiological Impact

Exsanguinating hemorrhage triggers the "bloody vicious cycle" characterized by:

• Profound acidosis (pH ≤7.2 predicts mortality) 3
• Hypothermia (temperature <34°C predicts mortality) 3
• Coagulopathy that develops in approximately one-third of severe trauma patients upon hospital arrival 1
• Hemodynamic instability with systolic blood pressure <90 mmHg and heart rate >120 bpm 4

Common Sources

Exsanguinating hemorrhage most frequently results from:

• Penetrating torso trauma affecting cardiopulmonary and vascular systems, with overall survival rates of only 8.8% after emergency thoracotomy (16.8% for stab wounds, 4.3% for gunshot wounds) 1
• Vascular damage in the head, neck, torso, or proximal extremities causing life-threatening hemorrhage 1
• Pelvic fractures with arterial bleeding requiring angiographic embolization 1
• Abdominal injuries with profound hemorrhage requiring damage control surgery 1

Critical Time Factors

Exsanguination is the leading cause of early preventable trauma deaths, with 74.3% of hemorrhagic deaths occurring either prehospital or within the first hour of hospital arrival. 5 The mortality risk increases by:

• 1% per minute of prehospital scene time 4
• 2% per minute of prehospital response time in penetrating trauma 4

Recognition in Clinical Practice

Identifying exsanguinating patients requires synthesizing:

• Trauma mechanism (penetrating versus blunt) 2
• Injury patterns and anatomic locations 1
• Vital signs showing profound shock 3
• Response to resuscitation: patients who are transient responders or non-responders to initial fluid therapy have exsanguinating injuries requiring immediate surgical intervention 2, 1

Immediate Management Priorities

All exsanguinating patients require immediate intervention (surgery and/or interventional radiology) for bleeding control without delay. 1 The treatment goals are:

• Stop the bleeding through surgical or radiological hemorrhage control 2
• Restore blood volume using massive transfusion protocols with predetermined ratios of blood components 6
• Reverse coagulopathy with aggressive component therapy 2
• Minimize time to definitive care, as delayed transfer to the operating room is a preventable cause of death 1, 4

Prognosis

Without immediate hemorrhage control, exsanguination is rapidly fatal. Predictive factors for mortality include:

• pH ≤7.2 3
• Temperature <34°C 3
• Operating room blood replacement >4,000 mL 3
• Total fluid replacement >10,000 mL 3
• Estimated blood loss >15 mL/minute 3

More than 50% of fatal trauma outcomes occur within 24 hours, with 34.5% classified as potentially preventable by early hemorrhage control. 5