In major trauma, the first problem you notice is not always the problem most likely to kill. A patient may be talking while losing a dangerous volume of blood. They may have an airway that looks clear while an evolving chest injury is restricting ventilation. The MARCH algorithm gives you a deliberate order of priorities when time and information are limited.
MARCH is used throughout Tactical Combat Casualty Care (TCCC) education and has strong relevance for prehospital teams, police, rescue personnel and trained first responders. It is not a replacement for your service protocol, clinical governance or judgement. It is a practical framework that helps you find and manage immediate threats, then reassess them as the patient’s condition changes.
This guide covers the five core stages only: Massive Haemorrhage, Airway, Respiration, Circulation and Hypothermia. You will learn what each stage means, why the order matters and how to build a disciplined MARCH assessment into your trauma response.
We recommend a MARCH-PAWS Cognitive Aide for field use.
Key Takeaways
- MARCH prioritises catastrophic bleeding before airway management because uncontrolled external haemorrhage can become fatal within minutes.
- The sequence is M — Massive Haemorrhage, A — Airway, R — Respiration, C — Circulation, H — Hypothermia.
- A limb tourniquet belongs high and tight when the wound is not visible in an unsafe setting; when the wound is exposed, place it 2–3 inches above the wound, never over a joint, and record the time.
- Airway and chest problems can deteriorate quickly. Treat, monitor and reassess after every intervention and movement.
- Shock care is more than fluid. It includes controlling bleeding, protecting perfusion, using IV/IO access and blood products under protocol, and considering TXA when indicated.
- Hypothermia prevention starts immediately, even in warm Australian conditions. A trauma patient can lose heat before they look cold.
What Is the MARCH Algorithm?
The MARCH algorithm is a trauma assessment and treatment sequence. It directs you to address the most immediate, reversible threats to life in a set order. It arose from USSOCOM tactical trauma protocols and is taught in the TCCC ecosystem, including NAEMT education. NAEMT describes MARCH as a guide to treatment priorities: control life-threatening bleeding, establish a patent airway, address respiratory threats, manage circulation, then prevent or treat hypothermia. NAEMT’s TCCC instructor material uses this same five-stage sequence.
| Letter | Stage | Primary Threat |
|---|---|---|
| M | Massive Haemorrhage | Exsanguination from life-threatening external bleeding |
| A | Airway | Obstruction or loss of a patent airway |
| R | Respiration | Tension pneumothorax, open chest wound, ventilation failure |
| C | Circulation | Shock, ongoing bleeding and inadequate organ perfusion |
| H | Hypothermia | Heat loss that worsens coagulopathy and trauma physiology |
You may know the older ABC approach: Airway, Breathing, Circulation. ABC remains useful in many medical presentations. MARCH changes the priority in trauma because a patient with catastrophic external bleeding can die before airway interventions can change the outcome. TCCC guidance therefore makes massive haemorrhage the first medical priority when it is tactically feasible to treat. Current TCCC guidance also emphasises that airway care may be deferred until the situation is safer and life-threatening bleeding is addressed.
Think of MARCH as a loop, not a checklist you complete once. A dressing can fail. A chest seal can need releasing. A conscious patient can become obtunded. When the scene changes, when you move the patient or when their observations change, return to MARCH.
M — Massive Haemorrhage
Massive haemorrhage comes first because blood loss has a short clock. Uncontrolled arterial bleeding can become fatal in less than three minutes. Look deliberately: scan the patient, their clothing, the ground and any obvious blood loss. Do not let distracting wounds pull your attention away from the largest threat.
For life-threatening bleeding from a limb, use a purpose-designed tourniquet. If you cannot see the wound in an immediate threat environment, apply it high and tight on the injured limb and move to a safer position. Once you can expose the wound, apply the tourniquet directly to skin 2–3 inches above the wound, avoid joints, tighten until bleeding stops and record the application time. If bleeding continues, tighten further or apply a second tourniquet side-by-side in accordance with your training and protocol. Never periodically loosen a tourniquet to “let blood through”.
For one-handed limb haemorrhage control, consider the TRUST Tactical Ratchet Tourniquet as part of a properly selected and practised trauma kit. The device is not the skill. You need to be able to identify life-threatening bleeding, apply it effectively and confirm that the bleeding has stopped.
The civilian evidence supports prompt, trained tourniquet use. A 2018 systematic review of 3,028 civilian tourniquet placements reported effectiveness rates of 78–100% and rare reported complications, under 2%. Read the PubMed record for the review. The authors also noted that the evidence base was low quality, which is a useful reminder to follow current local protocols and keep training.
Not every wound can take a limb tourniquet. Junctional wounds in the groin, axilla or neck, and other bleeding sites not amenable to a limb tourniquet, may require direct pressure and wound packing within your scope of practice. Find the source, pack gauze firmly and directly into the wound cavity, apply sustained direct pressure, secure the dressing and reassess for ongoing bleeding. A haemostatic gauze such as QuikClot Combat Gauze LE is designed for this role when used according to training and manufacturer instructions.
A systematic review of prehospital haemostatic dressings included 17 studies and 809 patients. It found QuikClot Combat Gauze was the most frequently applied dressing and reported a median bleeding-cessation rate of 90.5%; the review also found important limits in study quality. PubMed PMID 29728411 provides the full study details. That is useful evidence, not permission to pack blindly. You still need to expose, locate the bleeding source, pack effectively and check that the intervention is working.
A — Airway
After immediate catastrophic bleeding is controlled, assess the airway. Trauma can obstruct it with blood, vomit, secretions, loose tissue, swelling or altered anatomy. A patient who can speak clearly has a patent airway at that moment, but this can change quickly. Listen for gurgling, snoring or stridor. Watch for facial trauma, pooling secretions, reduced consciousness and escalating work of breathing.
Start simply and work within your scope. Use positioning, suction where available and appropriate, a chin lift or jaw thrust. A conscious patient may protect their airway best when sitting up or leaning forward. Place an unconscious patient who is breathing in the recovery position where this is appropriate to the situation. An NPA or OPA can assist selected patients when the responder is trained to use it and it is clinically appropriate.
Advanced airway decisions sit with appropriately trained clinicians. For intensive care paramedics (ICPs), HEMS and retrieval teams, video laryngoscopy can support difficult-airway management. The IntuBlade video laryngoscope is TGA registered (ARTG 529608), single-use and includes integrated lens clearing. Device familiarity, team preparation, oxygenation and a clear backup plan remain more important than any single piece of equipment.
R — Respiration
Respiration is about more than counting breaths. In trauma, actively look for tension pneumothorax, open chest wounds and haemothorax. A tension pneumothorax may present with severe or progressive respiratory distress, tachypnoea, reduced or absent breath sounds on one side, falling oxygen saturation, shock or traumatic cardiac arrest in the context of chest trauma. These signs are not exclusive, so use the whole clinical picture and your organisation’s protocol.
Seal an open or sucking chest wound promptly with a vented chest seal where available. Continue to monitor after the seal is applied. A deteriorating patient with chest trauma needs immediate escalation. Chest decompression is an advanced intervention and should only be performed by clinicians authorised, equipped and practised to do it.
If ventilation support is required, use a bag-valve-mask (BVM) with careful attention to airway position, seal, rate, chest rise and oxygenation. Good BVM ventilation is a skill that benefits from deliberate practice rather than a skill you first attempt under pressure. Sotair and SotairIQ support training scenarios that help teams recognise the effect of technique, timing and ventilation quality before a real emergency.
C — Circulation
In MARCH, circulation means identifying shock, restoring perfusion and checking that your earlier haemorrhage interventions are still effective. Assess mental state, skin signs, pulse quality and blood pressure where available. Look again for concealed or renewed bleeding. A controlled scene does not mean the patient is controlled.
Establish IV access when indicated and within scope. If IV access is required but cannot be obtained promptly, clinicians may use intraosseous access under their protocol. In haemorrhagic shock, current TCCC guidance prioritises blood products where available and protocolled, rather than indiscriminate crystalloid. The TCCC guidelines set out access, resuscitation and reassessment principles in detail.
For penetrating trauma without suspected traumatic brain injury (TBI), many trauma protocols use permissive hypotension while definitive bleeding control is pending, commonly aiming for a systolic pressure of about 80–90 mmHg or a palpable radial pulse. This approach is not for every patient. In suspected TBI, hypotension worsens outcome risk; current TCCC guidance targets a systolic pressure above 100 mmHg. Follow your local protocol, patient condition and senior clinical direction.
Tranexamic acid (TXA) may be indicated for patients in or at risk of significant haemorrhagic shock. It is time-sensitive. TCCC guidance advises giving TXA as soon as possible and no later than three hours after injury when indicated. It must be used under your approved protocol. While you are managing circulation, reassess every tourniquet, packed wound and pressure dressing. Continued bleeding is a circulation problem even if you treated it earlier.
H — Hypothermia
Hypothermia is not a later comfort measure. It is an early trauma intervention. Heat loss contributes to the lethal triad of hypothermia, acidosis and coagulopathy. As a patient becomes cold, clotting function can worsen. More bleeding drives shock and acidosis, which in turn makes clotting harder. The cycle is dangerous and self-reinforcing.
Begin prevention as soon as you can. Remove wet clothing when practical, protect the patient from wind and rain, place insulation between them and the ground, and use a casualty blanket or hypothermia system. Protect the head and keep the patient dry. Consider warmed fluids and active warming only within your service capability and protocol.
Do not wait for shivering or a low thermometer reading. Shock, exposed skin, wet clothing, rain, cold ground and helicopter wash can all strip heat quickly. TCCC guidance calls for early, aggressive prevention of further heat loss, including insulation from cold surfaces and protection from wind and precipitation.
MARCH PAWS: When the Assessment Extends Beyond MARCH
For clinicians and responders operating in prolonged field care or civilian tactical environments, the MARCH algorithm is often extended to MARCH PAWS — adding Pain management, Antibiotics, Wound reassessment, and Splinting. Read our full guide: MARCH PAWS — Tactical Trauma Assessment Framework Explained
MARCH remains the immediate five-stage framework in this article. Once those life threats are addressed, a prolonged-care setting may require further structured work. That is why you should understand the distinction rather than treating the acronym as one fixed, once-only checklist.
Training to Execute MARCH Under Pressure
Knowing the words is not the same as performing under pressure. Noise, poor light, gloves, blood, cramped access and a deteriorating patient all change how a procedure feels. Simulation builds automaticity. It helps you make the sequence familiar before cognitive load rises.
Build short, repeated scenarios around one decision at a time. Identify the bleed. Apply the tourniquet. Record the time. Recheck it after a patient move. Pack a wound while a colleague manages airway positioning. Apply a chest seal, then reassess when respiratory distress changes. Finish every scenario with a verbal MARCH handover.
For realistic haemorrhage-control practice, the Slishman Tourniquet Conversion Trainer lets learners practise the decision-making and hand skills involved in tourniquet conversion. The Tourniquet Conversion Training Bundle groups training resources for structured sessions. For airway and respiration practice, SotairIQ can support measurable manual-ventilation training.
Use simulation to test your team, not just your equipment. Clarify roles, call out findings, document key times and practise when to escalate. Then train again. That is how MARCH becomes a reliable clinical habit rather than a poster on a wall.
Frequently Asked Questions
What does MARCH stand for in first aid?
MARCH stands for Massive Haemorrhage, Airway, Respiration, Circulation and Hypothermia. It is a trauma-priority framework used in TCCC and related prehospital settings. It directs you to manage catastrophic external bleeding first, then address airway, breathing, shock and heat loss while reassessing throughout.
Why does MARCH address haemorrhage before airway?
MARCH puts massive haemorrhage first because a patient can lose a fatal amount of blood in minutes from uncontrolled external bleeding. When catastrophic bleeding is present, a tourniquet, wound packing or direct pressure may be the most time-critical intervention. Airway assessment follows as soon as that immediate bleeding threat is controlled or the situation allows.
What is the difference between MARCH and MARCH PAWS?
MARCH is the core five-stage immediate trauma assessment: Massive Haemorrhage, Airway, Respiration, Circulation and Hypothermia. MARCH PAWS extends care for prolonged or tactical environments by adding Pain management, Antibiotics, Wound reassessment and Splinting. MARCH comes first; the extension does not replace the immediate priorities.
Is the MARCH algorithm used in Australia?
MARCH is widely recognised in Australian tactical, prehospital, rescue and trauma-training contexts, particularly where TCCC principles influence training. Its use in a specific service depends on that organisation’s clinical governance, protocols, scope of practice and medical direction. Use the framework alongside, not instead of, your local system.
What tourniquet should I use for MARCH haemorrhage control?
Use a purpose-designed commercial limb tourniquet that is approved or accepted by your organisation and that you have practised using. Selection should consider current evidence, procurement standards, your operating environment and governance. For an example of a purpose-built option, see the TRUST Tactical Ratchet Tourniquet.
What is wound packing and when is it used?
Wound packing is the process of placing gauze firmly into a bleeding wound to put direct pressure on the bleeding source. It is used for selected external wounds not amenable to a limb tourniquet, such as junctional wounds, by trained responders working within protocol. It does not treat internal bleeding or replace urgent evacuation and definitive surgical care.
What are the signs of tension pneumothorax?
Suspect tension pneumothorax after significant chest trauma or blast injury when there is severe or worsening respiratory distress, rapid breathing, markedly reduced breath sounds on one side, low oxygen saturation, shock or traumatic cardiac arrest. These are high-risk signs that need urgent escalation and treatment under the applicable clinical protocol.
How does hypothermia affect trauma patients?
Hypothermia can impair clotting and worsen the trauma cycle of bleeding, shock and acidosis. A patient may become hypothermic even in a temperate climate because of exposure, wet clothing, blood loss and cold surfaces. Start insulation and heat-loss prevention early rather than waiting for visible signs of cold stress.
This article is for educational purposes only and does not constitute medical advice. MARCH algorithm skills must be practised and applied within your scope of clinical practice and under your organisation's clinical governance and protocols.