MARCH is a priority scheme for assessing and treating life-threatening injuries. The letters stand for Massive haemorrhage, Airway, Respiration, Circulation and Hypothermia/Head injury. In tactical casualty care, the scheme helps identify and treat problems that can rapidly cause death. During military isolation, the threat, the casualty’s remaining ability to act and the means actually available determine which interventions are possible.
Threat and phase of care
Under fire, inside a burning vehicle or in a comparable immediate danger, a detailed examination can expose people to further injury. During Care Under Fire/Threat, cover, moving out of the immediate danger and tactically feasible control of life-threatening external bleeding therefore take priority. A casualty who can still act moves to cover and begins self-aid with accessible means. Buddy aid requires a helper who can actually reach the casualty and perform an intervention or move them.
During Tactical Field Care, the reduction in immediate threat allows a more systematic examination. A life-threatening problem identified during that examination is treated immediately before proceeding. Heat-loss prevention can also begin during other interventions. If the threat changes again, the extent of care must change with it.
M – Massive haemorrhage
Severe bleeding removes both circulating volume and oxygen-carrying blood. Blood flow to the brain and other organs falls; the casualty may lose the ability to provide self-aid before a complete examination could be finished. Rapidly accumulating blood, a large pool of blood or uncontrolled bleeding from an injured arm or leg therefore demands early bleeding control. Massive bleeding need not visibly spurt.
If an external bleeding site is accessible and can be compressed, apply firm, sustained hand pressure to the wound, preferably through a clean dressing or available clean fabric. If dressings are absent, pressure with the casualty’s own hand may be the immediately available measure. Repeatedly lifting the material to inspect the wound, or washing a heavily bleeding wound, interrupts bleeding control. An embedded object stays in place; apply pressure around it. Once bleeding has been controlled, a suitable pressure dressing can maintain pressure. Its actual effect must then be checked.
For life-threatening arm or leg bleeding, a suitable tourniquet performs a different task: it interrupts blood flow to the injured limb. The trained application places it above the wound, between the injury and the torso, clear of a joint, and must stop the bleeding. Under immediate threat, rapid application over clothing is possible. A limb tourniquet does not go around the neck or torso. Haemostatic gauze supports local bleeding control in suitable compressible wounds together with direct pressure; packing it requires the specific trained technique. Both devices must be present and accessible. Mark an applied tourniquet with its application time and do not periodically loosen it on your own: bleeding can restart immediately.
A – Airway
The airway is the passage through which air reaches the lungs. Blood, damaged tissue or swelling after face and neck injuries can narrow or block it. Clear speech means air is currently passing through that passage; it does not rule out later deterioration. Response, voice and the passage of air therefore remain under observation after the first check.
A conscious casualty may adopt the position that best protects the airway. After a facial injury, sitting or leaning forwards may help blood drain. In tactical care, a capable helper places an unconscious casualty with normal spontaneous breathing in the recovery position, with the head tilted back and the chin away from the chest. Breathing must continue to be checked. Absent breathing or isolated gasps are not adequate spontaneous breathing. They require immediate reassessment of airway and breathing, together with trained support of breathing appropriate to the tactical situation. The recovery position alone does not correct this problem.
An airway obstruction that cannot be managed because of severe injury exceeds simple self-aid. Suction, airway adjuncts and a surgical airway are distinct procedures, each with its own training and equipment requirements. As consciousness declines, a lone injured person also loses the ability to maintain their own position reliably.
R – Respiration
An open airway does not establish whether the lungs are being ventilated adequately. After a chest injury or explosion, worsening breathlessness, unusually rapid breathing and visible effort to breathe are warning signs. An open chest wound can allow air to enter the space around the lung. Increasing air accumulation and pressure can prevent the lung from expanding and ultimately impair circulation as well. Airway and breathing are therefore assessed separately.
A helper trained for the procedure can treat an open chest wound with an actually available chest seal. Tactical care favours a purpose-made vented seal; observation is still required after application. Blood or clots can block the air outlet. If breathing becomes progressively worse after sealing the wound, care must be reassessed. Trained lifting or removal of the seal can allow trapped air to escape. Further decompression of the chest with a needle is a separate invasive intervention, not an improvised extension of that measure.
If the appropriate dressing and the ability to apply and monitor it are absent, do not close an open chest wound with an improvised airtight plastic construction. Such closure can worsen the pressure problem. Breathing effort and level of consciousness remain observable without a measuring device, although they cannot establish the precise injury inside the chest. Increasing breathlessness despite an open airway remains a life-threatening problem.
C – Circulation
C concerns remaining blood flow and missed or recurring blood loss. A weak or absent pulse at the wrist and a new change in consciousness can indicate haemorrhagic shock. Pallor, cold skin and dizziness strengthen that suspicion in the appropriate injury context. Confusion can also result from head injury or oxygen deficiency. It prompts another check of bleeding, airway and breathing rather than a premature assumption that the casualty is having an emotional reaction.
Check visible bleeding control: is blood flowing again beneath a dressing, is the tourniquet effective, is there a second wound previously hidden from view? Severe torso or pelvic injuries can also involve internal blood loss that does not form a visible pool. Pressure on an external wound does not stop that internal bleeding. Circulation can therefore continue to deteriorate after successful initial bleeding control.
When haemorrhagic shock is suspected, preventing further blood loss, rechecking breathing and starting heat-loss prevention are tasks that may be within reach. A drink does not replace lost blood. Clinical restoration of circulation with blood products requires actual suitable products, qualified personnel and the prescribed procedures. Without those means, severe internal bleeding or progressive shock remains beyond self-care.
H – Hypothermia and head injury
Hypothermia threatens a severely injured casualty even in a warm climate. Blood loss, reduced heat production, wet clothing and lying on a cold surface promote cooling. Cooling in turn impairs clotting and can contribute to further blood loss. Heat-loss prevention therefore begins early while other problems are being treated. The last letter does not mean leaving a casualty unprotected until that point.
Available clothing, a blanket or other suitable insulation protects the body and its contact with the ground; an outer wind and rain barrier limits further heat loss. A thin emergency foil blanket alone provides little ground insulation. Replace wet clothing only when dry clothing or a suitable dry thermal enclosure is ready. Without a replacement, retain the wet layers and add an appropriate vapour barrier and further insulation. An available suitable active heat source can warm the torso, but it must be used according to its instructions and protected against direct skin contact. Check the skin regularly for burns. Do not add active heat to a casualty with heat illness.
Head injury directs attention to injury of the head and changes in brain function. After a blow to the head or an explosion, increasing drowsiness, confusion or inability to follow a simple instruction must be taken seriously. A capable buddy can request a simple hand movement and later check the same response again. Oxygen deficiency and inadequate blood flow can cause additional injury to an already injured brain; A, R and C therefore remain decisive even with an obvious head injury. Do not attribute deteriorating consciousness solely to the head while blood loss or a breathing problem is also possible.
For an isolated casualty, impaired brain function also means worse orientation and less reliable self-aid. Limit further exertion; a continuing immediate threat may still force necessary movement. Do not routinely elevate the head and torso when shock is also present. Care considers airway, breathing and circulation together rather than a single suspected injury.
Meaning of the variants
The expression Hypothermia/Head injury groups two tasks under H: preventing heat loss and considering possible brain injury and changes in consciousness. The British Combat Life Saver model uses MARCH in place of the earlier CABC – Catastrophic haemorrhage, Airway, Breathing, Circulation. Critical bleeding remains first, while heat loss and head injury are explicitly included in the mnemonic.
MARCH is also used for care under cover in the German Wachbataillon’s homeland defence training; H is explained there as protection against cooling. The airway adjuncts or invasive interventions a soldier is trained and authorised to perform depend on their actual training and care system. The shared mnemonic therefore corresponds to different sets of feasible interventions for a lone casualty, a trained buddy and a combat medic.
Reassessment whenever conditions change
After an intervention, check whether it has actually improved the problem identified. After movement, repositioning or new deterioration, revisit the life-threatening problems: bleeding, airway, breathing, circulation and consciousness. Dressings can move, a wound can start bleeding again and initially adequate breathing can deteriorate. Heat-loss prevention and observation continue throughout. A controlled bleed does not remain controlled merely because M has already been completed.
A lone casualty must start with accessible means while their hands and consciousness still allow action. Sustained manual pressure can substantially restrict the use of a hand and therefore movement or equipment operation. If a casualty card or another portable means of recording information is available, record findings, application times and changes on it and keep it with the casualty. If a real communication link or recovery opportunity later becomes available, those details are ready for handover. Until further care is actually possible, recognising recurrent bleeding or deterioration and maintaining the measures that remain effective are essential.