Blast Injury Management: Triage and Treatment Principles for Australian First Responders

A blast event produces a pattern of injury unlike almost anything else first responders encounter. A single explosion can generate blunt trauma, penetrating trauma, burns, crush injury, and barotrauma simultaneously, in the same patient, often before the scene is fully secured. For Australian paramedics, police, and emergency services personnel, blast events are thankfully rare, but the injury patterns and triage discipline they demand are directly relevant to bombings, industrial explosions, gas incidents, and even large-scale vehicle or workplace accidents involving pressurised systems.

Military and disaster medicine research has spent two decades refining how blast injuries should be classified, triaged, and treated, driven largely by the intensity of combat and terrorism-related casualty data from the past twenty years. Much of that evidence now directly informs civilian mass casualty planning, including Australian emergency management frameworks. Understanding the mechanism-based classification of blast injury, and applying triage systems suited to a scene where the threat may not yet be over, are core skills for any responder who could plausibly face a mass casualty incident.

This article works through the classification of blast injuries, the clinical features of each category, triage approaches suited to blast and mass casualty scenes, and the treatment priorities that make the greatest difference to survival. It draws on Department of Defense blast injury taxonomy, peer-reviewed emergency medicine literature, and disaster medicine guidance relevant to Australian first responder practice.

The Five Categories of Blast Injury

The current framework used across defence and emergency medicine internationally, including by the Blast Injury Research Coordinating Office, divides blast injuries into five categories based on mechanism (BIRCO):

Category	Mechanism	Typical injuries
Primary	Blast overpressure wave	Blast lung (pulmonary barotrauma), tympanic membrane rupture, abdominal haemorrhage and perforation, globe rupture, concussion
Secondary	Fragments and debris propelled by blast wind	Penetrating fragmentation wounds, eye penetration, open or closed brain injury
Tertiary	Body displacement by blast wind and pressure gradients	Blunt trauma similar to falls or vehicle collisions, fractures, traumatic amputation
Quaternary	All other explosion-related effects	Burns, crush injury, toxic gas or dust inhalation, exacerbation of chronic illness
Quinary	Additives in the explosive device (bacteria, chemicals, radiological material)	Hyperinflammatory states, contamination-related illness

Primary blast injury is unique to explosive mechanisms and does not occur from any other trauma type, which is why it is worth understanding in detail even for responders who rarely encounter blast events.

Why Primary Blast Injury Deserves Special Attention

Air-filled and gas-containing organs are disproportionately vulnerable to the overpressure wave of an explosion. The lungs, middle ear, and bowel are the classic sites of primary blast injury, and blast lung in particular can present with a delayed or evolving clinical picture (PMC — Blast Injuries).

Clinical features of blast lung (pulmonary barotrauma) include:

• Dyspnoea and tachypnoea
• Cough, ranging from dry to productive with frothy or blood-streaked sputum
• Chest pain, typically retrosternal
• Reduced breath sounds, dullness to percussion, or coarse crepitations
• Signs of pneumothorax or haemopneumothorax
• Subcutaneous emphysema or retrosternal crunch, suggesting pneumomediastinum

Any patient evacuated from close proximity to an explosion should be assessed for pulmonary, otological, and abdominal effects of primary blast injury even in the complete absence of visible external wounds. This is a critical and frequently underappreciated point: the absence of obvious trauma does not mean the absence of primary blast injury.

Chest imaging in a hospital setting will typically show diffuse infiltrates that progress over 24 to 48 hours, and a delayed deterioration beyond 48 hours can indicate complications such as acute respiratory distress syndrome or pneumonia (PMC — Blast Injuries). Prehospital management centres on high-flow oxygen and careful, judicious fluid administration, since aggressive fluid resuscitation can worsen pulmonary oedema in a lung already compromised by barotrauma. If tension pneumothorax develops, immediate decompression is required.

The Two Deadliest Categories: Head Injury and Extremity Haemorrhage

Retrospective analysis of fatal injuries from improvised explosive devices provides a sobering picture of where blast deaths actually occur. A cohort study of IED fatalities found that in dismounted casualties (those on foot at the point of wounding), the leading causes of death were extremity haemorrhage (42.6 percent of fatal injuries), junctional haemorrhage (22.2 percent), and traumatic brain injury (18.7 percent) (Kotwal et al., BMJ Open). In mounted casualties (in-vehicle at the point of wounding), traumatic brain injury dominated, accounting for around half of fatal injuries.

This matters because it identifies where prehospital intervention has the greatest leverage. Extremity and junctional haemorrhage are largely treatable at the point of injury, whereas severe traumatic brain injury generally is not. The same research found that roughly two-thirds of dismounted fatalities died from haemorrhage that may have been anatomically amenable to prehospital intervention, underscoring why haemorrhage control remains the single highest-value skill a first responder can bring to a blast scene.

The Evidence for Early Tourniquet Application

The survival data on tourniquet timing is unusually clear for a field where clean outcome studies are hard to obtain. Analysis cited in the U.S. Army Medical Center of Excellence extremity injury guidance found that tourniquet placement before the onset of shock is associated with 96 percent survival, compared with only 4 percent survival when application is delayed until after shock has developed (MEDCoE Extremity Injury). The same source notes that early prehospital tourniquet application saves approximately 11 percent more lives compared with delayed in-hospital application.

A separate prospective study of casualties requiring tourniquets found that when shock was absent at the time of application, survival was 90 percent, compared with 10 percent when shock was already present. Critically, the five casualties in that study who were indicated for a tourniquet but did not receive one had a 0 percent survival rate, compared with 87 percent survival among those who did (tourniquet outcomes study). No limbs were lost as a direct result of tourniquet use in that cohort.

This evidence base is the foundation for why products such as the TRUST Tactical Ratchet Tourniquet are designed for rapid, one-handed application — speed to control is directly linked to survival, and a tourniquet that can be applied correctly in under 10 seconds by a stressed, possibly injured responder has genuine clinical value beyond convenience.

Current guidance recommends tourniquet reassessment within two hours of application, since prolonged application carries its own risks of ischaemia-reperfusion injury, nerve palsy, and, in extreme cases, compartment syndrome. Conversion from a tourniquet to a wound-packing and pressure dressing approach should follow local protocol once bleeding control allows for it.

Triage in a Blast or Mass Casualty Scene

Routine trauma triage assumes adequate resources to treat the patient in front of you. Mass casualty and blast triage inverts that assumption: the objective becomes doing the greatest good for the greatest number of casualties, which sometimes means withholding resource-intensive care from patients unlikely to survive so that resources remain available for salvageable casualties (Journal of Trauma and Acute Care Surgery).

Common Triage Categories

Most systems, including START (Simple Triage and Rapid Treatment) and SALT (Sort, Assess, Life-saving Interventions, Treatment/Transport), sort casualties into four broad categories:

Category	Description	Typical time to treatment
Immediate (Red)	Airway compromise, uncontrolled haemorrhage, open chest wounds, hypotension	Within 1 hour
Delayed (Yellow)	Serious but not immediately life-threatening — open fractures, vascular injury without active exsanguination	4–6 hours
Minimal (Green)	Walking wounded, minor soft tissue injury	As resources allow
Expectant (Black)	Injuries incompatible with survival given available resources — severe head injury, cardiac arrest, extensive burns	Not prioritised for resource-intensive care

START uses a simple physiological sieve: can the patient walk, are they breathing, what is their respiratory rate, do they have a radial pulse, and can they follow simple commands (mass casualty triage review). Neither START nor SALT is scientifically proven superior in all situations, and current guidance emphasises that regular training and familiarity with a chosen system matters more than which specific algorithm is used (systematic review of MCI management).

Tactical Triage in an Active or Uncertain Threat Environment

Blast scenes, particularly those involving deliberate attacks, introduce a complication that standard triage systems were not designed for: the threat may not be over. The Committee for Tactical Emergency Casualty Care notes that current triage tools are largely inadequate for this "warm zone" setting, where responder stress is high and the security situation is not yet controlled (C-TECC triage guidance).

In this environment, the Hartford Consensus recommends the THREAT framework for first responders:

1. Threat suppression
2. Haemorrhage control
3. Rapid extrication to safety
4. Assessment by medical providers
5. Transport to definitive care

This sequencing reflects a hard-won lesson from complex, coordinated attacks: casualty care in an active threat zone must be rapid, simple, and focused overwhelmingly on haemorrhage control, deferring detailed assessment and secondary triage until casualties reach a controlled casualty collection point.

Secondary Devices and Scene Safety

Bombing incidents have a documented history of secondary devices deliberately placed to target first responders, rescue personnel, and returning casualties. Disaster medicine literature explicitly recommends establishing triage sites away from the original blast scene, and maintaining awareness of the possibility of a second device throughout the response (Journal of Trauma and Acute Care Surgery). This is not an abstract precaution — it is a recurring feature of real-world bombing incidents and should be built into scene management from the first radio call.

Treatment Priorities After Triage

Once triage has occurred and immediate-category casualties are identified, treatment priorities at the point of injury and casualty collection point generally follow this order:

1. Control external haemorrhage — tourniquet for extremity bleeding, wound packing and haemostatic dressing for junctional or difficult-to-tourniquet sites.
2. Manage the airway — clear obstruction, consider positioning, use airway adjuncts as trained.
3. Address chest injuries — decompress suspected tension pneumothorax, seal open chest wounds, monitor for evolving blast lung.
4. Splint fractures and cover wounds — reduces pain and further bleeding, and prepares the casualty for movement.
5. Reassess primary blast injury indicators — ears, chest, and abdomen, even without visible external trauma.
6. Prepare for evacuation — prioritise by triage category, not by order of arrival at the collection point.

Extensive or definitive treatment is deliberately deferred at this stage. The priority is stabilisation sufficient for evacuation, not resolution of every injury.

Comparing Blast Injury Categories at a Glance

Category	Time course	Detectability	Key first responder action
Primary (blast lung, TM rupture)	May be delayed 24–48 hours	Often no external signs	High-flow oxygen, judicious fluids, monitor respiratory status
Secondary (fragmentation)	Immediate	Usually visible	Haemorrhage control, wound coverage
Tertiary (blunt trauma from displacement)	Immediate	Often visible, may be occult (internal)	Standard blunt trauma assessment, spinal precautions where indicated
Quaternary (burns, crush, inhalation)	Immediate to delayed	Usually visible	Burn management, crush syndrome awareness, airway protection from inhalation injury
Quinary (contamination)	Delayed	Not visible without testing	Decontamination protocols, hazard awareness, PPE

Frequently Asked Questions