Trauma remains a leading cause of potentially preventable death in modern warfare. While advances in haemorrhage control, resuscitation strategies, and evacuation platforms have significantly improved survival, a substantial proportion of casualties still deteriorate due to physiological failure rather than anatomical injury. Central to this failure is the Trauma Triad of Death – hypothermia, metabolic acidosis, and trauma-induced coagulopathy, a self-reinforcing cycle strongly associated with increased morbidity and mortality (Remondelli et al., 2025).

In contemporary and future operating environments – defined by dispersed forces, contested evacuation, and prolonged field care (PFC) – management of the trauma triad is no longer confined to Role 2 or Role 3 facilities. This article describes how prevention of the triad is a core Role 1 responsibility, embedded within correct execution of Tactical Combat Casualty Care (TCCC) and the MARCH algorithm (Massive Haemorrhage, Airway, Respiration, Circulation, and Hypothermia/Head injury).

The Trauma Triad of Death: A Contemporary Understanding

Modern trauma research demonstrates that hypothermia, acidosis, and coagulopathy develop early and concurrently, often within minutes of injury, particularly in the presence of uncontrolled haemorrhage and shock (Moore et al., 2021). These processes do not occur in isolation; each worsens the others, accelerating physiological collapse.

Crucially, the trauma triad is not something treated after MARCH, it is prevented through the disciplined application of MARCH from the first intervention.

Hypothermia

Trauma-related hypothermia is frequently shock-driven and iatrogenic (meaning accidental hypothermia because of interventions such as medication administration including but not limited to anaesthetics, beta-blockers and clonidine as well as cold fluid administration), rather than purely environmental. Haemorrhage reduces metabolic heat production, while exposure during assessment, wet clothing, wind, and unwarmed fluids accelerate heat loss. Even mild hypothermia impairs platelet function and coagulation enzyme activity, increasing bleeding and mortality risk (Bennett et al., 2020).

Prevention and Treatment (MARCH / TCCC)

Although listed last in the MARCH sequence, hypothermia prevention must occur throughout all phases of care:

M (Massive Haemorrhage): Early haemorrhage control limits shock-related heat loss.

A/R (Airway / Respiration): Rapid, exposure-minimising airway and respiratory interventions.

C (Circulation): Avoidance of excessive crystalloid. Use of warmed blood products where available.

H (Hypothermia / Head Injury): Immediate insulation from ground and wind, hypothermia prevention kits or thermal blankets, minimised exposure, and active warming where possible.

TCCC doctrine identifies hypothermia prevention as life-saving treatment, not comfort care, and mandates early intervention in all climates (Committee on Tactical Combat Casualty Care, 2024).

Metabolic Acidosis

Metabolic acidosis results from inadequate tissue perfusion and oxygen delivery, leading to anaerobic metabolism and lactate accumulation. Persistent acidosis reduces myocardial contractility, diminishes catecholamine responsiveness, and directly impairs coagulation factor activity (Moore et al., 2021). Acidosis is therefore a marker of unresolved shock, not a primary biochemical disorder.

Simply put, when the body doesn’t receive enough blood flow and oxygen, its cells are forced to produce energy in an inefficient way. This causes acids to build up in the bloodstream. If this acidic state continues, it weakens the heart’s ability to pump, makes the body’s stress responses less effective, and interferes with normal blood clotting.

As a result of this, acidosis should be seen as a warning sign that shock or poor circulation has not yet been fixed, rather than a problem on its own.

Prevention and Treatment (MARCH / TCCC)

Preventing acidosis is about fixing blood flow and oxygen delivery to the body, not about trying to “neutralise” the acid with chemicals:

M (Massive Haemorrhage): Tourniquets, haemostatic dressings, and pelvic stabilisation preserve circulating volume.

A/R (Airway / Respiration): Effective airway management and treatment of thoracic injury optimise oxygen delivery.

C (Circulation): Permissive hypotension (where appropriate), avoidance of excessive crystalloid, and early use of blood or blood products.

Pharmacological buffering has no Role 1 application without correction of perfusion deficits (Remondelli et al., 2025).

Trauma-Induced Coagulopathy

Trauma-induced coagulopathy (TIC) is the body’s early reaction to serious injury, where the normal ability of the blood to clot is disrupted. It is triggered by damage to tissues, poor blood flow, injury to blood vessels, and problems with the body’s system for controlling bleeding.

When the body also becomes cold or too acidic, clotting works even less effectively, which increases bleeding and makes shock worse (Moore et al., 2021).

Prevention and Treatment (MARCH / TCCC)

Prevention of TIC begins at the point of injury:

M (Massive Haemorrhage): Immediate haemorrhage control prevents clot consumption.

C (Circulation): Damage Control Resuscitation principles. Minimal crystalloid, early blood or whole blood, balanced component therapy where available.

C/H (Circulation / Hypothermia): Aggressive hypothermia prevention preserves enzymatic clotting function.

C (Circulation): Early administration of tranexamic acid (TXA) within guideline timeframes.

These interventions directly target the physiological drivers of TIC and are achievable, at least in part, even in austere Role 1 environments (Committee on Tactical Combat Casualty Care, 2024; Remondelli et al., 2025).

Teaching Aid: MARCH and the Trauma Triad of Death (Role 1 Quick Reference)

Key Principle: The trauma triad is not treated later; it is prevented through disciplined MARCH execution.

M – Massive Haemorrhage: Stops the driver of shock, limits acidosis, preserves clotting, reduces heat loss.

A – Airway: Maintains oxygen delivery, preventing hypoxic acidosis.

R – Respiration: Corrects hypoxia, supporting cardiac and coagulation function.

C – Circulation: Preserves physiology through permissive hypotension, blood-based resuscitation, and TXA.

H – Hypothermia: Continuous insulation and warming prevent clotting failure and physiological decline.

Role 1 Vignette: Preventing the Triad Forward

A dismounted infantry patrol sustains an IED strike during limited visibility operations. One soldier presents with a traumatic lower-limb amputation and suspected pelvic injury. Enemy activity delays evacuation.

Role 1 Actions: A tourniquet is applied immediately, followed by pelvic stabilisation and haemostatic dressings. Recognising early shock, the team avoids unnecessary exposure, deploys a hypothermia prevention kit, and insulates the casualty from the ground.

Crystalloid use is avoided. Permissive hypotension is maintained while monitoring mental status and pulse quality. Active warming continues throughout.

Outcome: When evacuation becomes available hours later, the casualty arrives normothermic, with haemorrhage controlled and shock partially mitigated. Demonstrating how Role 1 prevention of the trauma triad directly influences survivability.

Key Lesson: Role 1 clinicians are not passive stabilisers but active preventers of physiological collapse. Early, disciplined interventions can halt progression into the full trauma triad long before surgical care is available.

Prolonged Field Care (PFC) Implications

In PFC scenarios, early interruption of the trauma triad may be temporary. Hypothermia, acidosis, and coagulopathy can recur if warming, perfusion, and haemostasis are not sustained (Remondelli et al., 2025). This reinforces the need for ongoing reassessment and sustained physiological support at Role 1 and Role 2.

Conclusion

The trauma triad of death remains a dominant mechanism of battlefield mortality. Hypothermia, acidosis, and coagulopathy are early, interdependent threats, best prevented (not reacted to) through disciplined application of TCCC and the MARCH algorithm.

In future conflicts characterised by delayed evacuation and prolonged care, the ability of Role 1 teams to recognise and prevent the trauma triad will remain a decisive determinant of combat survivability.