In the Field
Preventable cause of death is the term that drives every piece of equipment in your IFAK and every minute of your training. The reason you carry a tourniquet is that extremity hemorrhage is the leading preventable cause of battlefield death. The reason you carry a chest seal and a needle is that tension pneumothorax is the second. The reason you train airway management is that airway obstruction is the third. The list is short by design. Tactical medical doctrine is built around the small number of injuries that are killing patients in the field who do not have to die.
Common Mistake
Building a kit or training program around what looks medically interesting rather than around the small list of preventable causes of death that drive actual battlefield mortality.
Technical Detail
The preventable cause of death framework emerged from analysis of combat fatalities in the Vietnam War and was refined through Iraq and Afghanistan combat data. The U.S. military's Joint Trauma System and the Committee on Tactical Combat Casualty Care examined cases where combatants died before reaching definitive medical care, asking which deaths could have been prevented with field interventions available at the time.
The findings consistently identified a small number of conditions responsible for the overwhelming majority of preventable battlefield deaths.
The three primary preventable causes of death:
Extremity hemorrhage. Uncontrolled bleeding from an arm or leg. Identified as the single largest category. Addressed in the field by tourniquets, hemostatic dressings, pressure dressings, and direct pressure. The development of effective windlass-style tourniquets such as the CAT and SOFTT-W and their adoption into routine carry has dramatically reduced extremity hemorrhage deaths since the early 2000s.
Tension pneumothorax. Air accumulating in the chest cavity, compressing the heart and lungs. Addressed in the field by chest seals (for prevention via the open pneumothorax pathway) and needle decompression (for treatment of established tension pneumothorax).
Airway obstruction. Loss of a patent airway due to direct injury, unconsciousness, or facial trauma. Addressed in the field by positioning, nasopharyngeal airway insertion, suctioning where available, and (at provider level) supraglottic airways or surgical cricothyroidotomy.
Why this list matters. The preventable cause of death framework does several things at once:
It prioritizes training. The MARCH algorithm exists because Massive Hemorrhage, Airway, Respiration are the leading preventable kill chains.
It prioritizes equipment. The IFAK contains the items that address the three primary preventable causes. Other items are secondary or are present because they support the primary interventions.
It justifies procurement. When a department is asked why a tourniquet costs $30 or why a chest seal costs $15, the answer is that these specific items are the field interventions for the leading preventable causes of death. The cost is justified by the mortality the item is positioned to prevent.
It guides protocol development. Tactical medical protocols, training cycles, and after-action reviews are organized around the question of whether preventable deaths occurred and what changes would prevent the next one.
Ongoing refinement. The list is not static. Military and civilian trauma research continues to identify additional preventable causes that drive significant mortality, including hemorrhagic shock progression (addressed by blood products and TXA), hypothermia (addressed by warming), and increasingly hypocalcemia (addressed by calcium administration in massive transfusion protocols). The Lethal Diamond reflects this ongoing refinement.
The preventable cause of death framework is one of the most important conceptual contributions of modern tactical medicine. It transformed trauma response from a generalized "treat everything you find" approach into a focused doctrine that prioritizes the small number of injuries actually responsible for field mortality.
