Trauma resuscitation is not only about replacing lost blood.
It is about preventing physiology from collapsing into a self-reinforcing cycle of bleeding and shock.
The classic lethal triad is hypothermia, acidosis, and coagulopathy.
Hypothermia impairs coagulation enzyme activity and platelet function. Even modest drops in core temperature can make clot formation less effective.
Acidosis also impairs coagulation. Low pH reduces the function of clotting factors and worsens myocardial performance. As shock deepens, tissue hypoperfusion increases lactate production, worsening acidosis further.