Hemorrhage Control and Hemostasis

Hemorrhage control is the stopping of bleeding after injury, and hemostasis is the body's own process of forming and stabilising clot. Because hemorrhage is the leading cause of potentially preventable death after trauma, early control of bleeding, by mechanical means and by supporting clotting, is a defining priority of the circulation step of the primary survey.

Definition

Hemorrhage control comprises the measures used to stop bleeding after injury, ranging from direct pressure and tourniquets for external bleeding to definitive surgical or interventional source control for internal bleeding; hemostasis refers to the physiological clotting process these measures aim to achieve and protect.

Scope

This topic covers the concepts of external and internal hemorrhage control, the principle of source control, trauma-induced coagulopathy, and the supportive role of antifibrinolytic therapy. It is a reference description of how the field thinks about stopping bleeding and supporting clot; it does not give techniques, drug doses, timing windows, or individualised procedural or treatment instruction.

Core questions

• How does the approach to external bleeding differ from that to internal (compartment) bleeding?
• What is trauma-induced coagulopathy, and why does it matter for hemorrhage control?
• Why is the timing of measures that support clotting important?

Key concepts

• External hemorrhage control (direct pressure, tourniquets, wound packing)
• Source control for internal hemorrhage
• Trauma-induced coagulopathy
• Fibrinolysis and antifibrinolytic therapy
• The lethal triad (hypothermia, acidosis, coagulopathy)
• Damage-control surgery

Mechanisms

Bleeding is controlled either by directly occluding the bleeding vessel, mechanically through pressure, packing, a tourniquet, or surgery, or by supporting the clotting that seals it. Severe injury can disturb clotting itself: tissue trauma and shock can trigger an early trauma-induced coagulopathy, which dilution from fluids, acidosis, and hypothermia further worsen, so that bleeding becomes harder to stop. Excessive breakdown of formed clot (hyperfibrinolysis) can also drive ongoing loss, which is the rationale for antifibrinolytic therapy in selected bleeding patients. Definitive control of an internal source frequently requires surgery or interventional radiology, sometimes staged as damage-control surgery, because external measures cannot reach a deep bleeding site.

Clinical relevance

Stopping hemorrhage is among the highest-yield actions in trauma care and is central to civilian and prehospital bleeding-control initiatives, so its principles are important for clinicians and for appraising trauma evidence. This entry presents those principles conceptually and is not a source of techniques, drug doses, timing thresholds, or individualised treatment decisions.

Epidemiology

Hemorrhage is the most common cause of potentially preventable death after injury. Analysis of combat fatalities by Eastridge et al. (2012) found that the great majority of potentially survivable deaths were attributable to hemorrhage, a finding that has strongly shaped the prominence of early bleeding control in both military and civilian trauma systems.

History

Direct measures to arrest bleeding are ancient, but the modern emphasis on rapid hemorrhage control was reinforced by twenty-first-century military experience, which revived widespread use of tourniquets and wound-packing agents and informed civilian prehospital bleeding-control programmes. The CRASH-2 trial (2010) provided large-scale evidence on antifibrinolytic therapy in trauma hemorrhage, and growing recognition of trauma-induced coagulopathy reshaped how early bleeding is understood and managed.

Debates

How should antifibrinolytic therapy be targeted in trauma hemorrhage?

CRASH-2 showed a mortality reduction overall, with analyses suggesting the timing of administration influences benefit and possible harm; how best to select patients and timing, including the role of viscoelastic testing, remains discussed.

Seminal works

• crash2-2010
• eastridge-2012
• rossaint-2023

Frequently asked questions

What is trauma-induced coagulopathy?

It is an impairment of the blood's ability to clot that can begin early after severe injury, driven by tissue trauma and shock and worsened by dilution, acidosis, and hypothermia, making bleeding harder to control.

Why is hemorrhage control such a high priority in trauma?

Hemorrhage is the most common cause of potentially preventable death after injury, so stopping bleeding early, by mechanical means and by supporting clotting, is one of the highest-yield interventions in trauma care.