The M.A.R.C.H. algorithm is a systematic, prioritized method for trauma care, providing a structured approach to address immediate, life-threatening injuries. This mnemonic device originated from Tactical Combat Casualty Care (TCCC) principles, developed for use by first responders and medical personnel in high-threat environments. The core purpose of M.A.R.C.H. is to sequence interventions based on the speed at which an injury can cause death, ensuring the most rapidly fatal conditions are addressed first.
Massive Hemorrhage Control
The M stands for Massive Hemorrhage, placed first because a patient can bleed to death from a major artery in as little as 60 to 120 seconds. Uncontrolled external bleeding is the most preventable cause of death in trauma. Immediate action to stop blood flow takes precedence over assessing a patient’s airway or breathing, as a clear airway is irrelevant without circulating blood to oxygenate.
For severe, life-threatening bleeding on the arms or legs, the immediate application of a commercial tourniquet is the recommended intervention. Tourniquets must be applied high and tight, two to three inches above the wound directly on the skin, and tightened until the bleeding stops completely and the pulse below the device is absent. For bleeding in areas where a tourniquet cannot be placed, such as the neck, armpit, or groin (known as junctional areas), specialized hemostatic dressings are used. These dressings, often impregnated with clotting agents like kaolin, must be packed directly into the wound and held with firm pressure for a minimum of three minutes to encourage clot formation and staunch the bleed.
Airway Management
Once massive external bleeding is controlled, the A directs attention to Airway Management. Securing a patent passage for air is the next life-saving step, as a patient with a compromised airway quickly becomes hypoxic. Asking if the patient can speak is a simple assessment to determine if the airway is clear.
If the patient is unconscious or has signs of an obstructed airway, simple manual techniques should be used first. The jaw-thrust maneuver is preferred in trauma patients to open the airway without moving the neck, which is important if a spinal injury is suspected. If manual maneuvers are insufficient, a basic airway adjunct like a Nasopharyngeal Airway (NPA), a flexible tube inserted through the nose, can be used to bypass an obstruction caused by the tongue or soft tissues. These adjuncts help maintain an open passage for air until more advanced care can be provided.
Respiration Assessment and Treatment
Following a secured airway, the R addresses Respiration, focusing on the mechanics of breathing and lung function. This step looks for chest cavity injuries that impair the body’s ability to oxygenate the blood. The most immediate threat is a tension pneumothorax, where air leaks into the chest cavity, building pressure, collapsing a lung, and pushing against the heart.
Signs of this condition include severe respiratory distress, a rapid heart rate, and an absence of breath sounds on one side of the chest. Any open wound to the chest, known as a “sucking chest wound,” must be immediately sealed with an occlusive dressing or chest seal to prevent air from entering the chest cavity. If a tension pneumothorax is suspected, a life-saving procedure called needle decompression is performed, which involves inserting a large-bore needle into the chest wall to release the trapped air and restore lung function.
Circulation and Shock Management
The C stands for Circulation, shifting focus to internal bleeding, the systemic response to blood loss, and restoring core volume. This phase involves assessing the patient for signs of hemorrhagic shock, such as a weak radial pulse, pale skin, and altered mental status. While external bleeding was addressed first, this step manages non-compressible internal hemorrhage, particularly in the abdomen or pelvis.
Establishing vascular access, either intravenously (IV) or intraosseously (IO) through the bone marrow, is a priority to allow for fluid administration and medication delivery. Current trauma guidelines advocate for a restrictive fluid strategy, prioritizing the use of blood products, such as whole blood or packed red blood cells, over simple saline solutions to replace lost oxygen-carrying capacity. Medications like Tranexamic Acid (TXA) may also be given to help stabilize clots and minimize ongoing blood loss.
Hypothermia Prevention and Head Injury
The final step, H, covers Hypothermia Prevention and Head Injury, which are addressed after all immediate life threats have been stabilized. Hypothermia, defined as a core body temperature below 95°F (35°C), is a significant complication in trauma that worsens both bleeding and shock. It is a component of the “lethal triad” of trauma, alongside acidosis and coagulopathy, where low body temperature impairs the blood’s ability to clot effectively.
Preventing heat loss is accomplished by aggressive measures such as removing wet clothing, insulating the patient from cold surfaces, and wrapping them in specialized warming blankets or hypothermia-prevention kits. Simultaneously, head injuries are assessed and managed by focusing on preventing conditions that can worsen brain damage, primarily low oxygen levels and low blood pressure. Maintaining a patient’s core temperature and ensuring adequate oxygenation complete the initial systematic approach to trauma care.