2 - Hemorrhagic Shock

Hemorrhage is an acute loss of circulating blood volume. Normal BV is approx 7% of IBW, or 70-80 mL/kg for children.

Class	Definition	Estimated Blood Loss	Clinical Clues
Class I hemorrhage	<1 unit of blood	<15%	Minimal, can have some tachycardia
Class II hemorrhage	uncomplicated hemorrhage requiring IV fluids	15-30%	narrow pulse pressure, elevated DBP. Subtle CNS changes
Class III hemorrhage	complicated hemorrhage; crystalloids are mandated and consider blood as well	31-40%	AMS, decr SBP, narrow pulse pressure
Class IV hemorrhage	preterminal event, the patient will die within minutes. Blood transfusion (Massive Transfusion) is required	>40%

Modifying factors for recognizing shock: patient age (extremes of age), severity of injury, time lapse between injury and initiation of treatment, prehospital fluid therapy, and medications for chronic conditions (antihypertensive, beta blockers, etc).

Initial Management of Hemorrhagic Shock

1. ABCDEs
2. Vascular access, initial bloodwork.
3. Initial fluid therapy (warmed isotonic crystalloids): 1 litre for adults and 20 mL/kg for pediatric patients <40 kg
4. Consider "controlled resuscitation" - permissive hypotension to reduce bleeding risk as a bridge to definitive control of bleeding.

Transfusion in Hemorrhagic Shock

1. Crossmatched blood is preferred.
2. Unmatched type-specific is next.
3. Type O pRBC are indicated if needed urgently
   1. Rh-negative for females of child-bearing age
   2. Rh agnostic otherwise!
4. Tranfuse PRN and carefully according to clinical status and coagulation/CBC studies, consider activation of Massive Transfusion protocol.
   1. TXA: 1g x 1 within 3 hours, and 1g over 8 hours afterwards
   2. Calcium administration
   3. Avoid hypothermia
   4. Aggressively treat acidosis