Hemorrhage Control and Shock

Objectives of the Chapter

  • List the four components of the vascular system needed for normal tissue perfusion:

    • Blood volume

    • Blood vessels

    • Heart function

    • Blood pressure

  • Describe the signs and symptoms of shock in order of presentation, distinguishing from compensated to uncompensated:

    • Compensated Shock: Weakness, pallor, tachycardia, narrowed pulse pressure, thirst, delayed capillary refill

    • Decompensated Shock: Hypotension, weak or no peripheral pulse, prolonged capillary refill

  • Describe the three common clinical shock syndromes:

    • Hypovolemic Shock, Distributive Shock, Obstructive Shock, and Cardiogenic Shock

  • Explain the pathophysiology of:

    • Hemorrhagic shock

    • Mechanical (obstructive) shock

    • Cardiogenic shock

    • Distributive shock

  • Describe the management of hemorrhage that can be controlled and cannot be controlled, and discuss non-hemorrhagic shock syndromes.

  • Discuss the use of tourniquets and hemostatic agents for uncontrolled extremity hemorrhage

  • Discuss the current indications for the use of IV fluids and tranexamic acid in the treatment of hemorrhagic shock.

General Understanding of Shock

  • Definition:

    • A life-threatening, generalized form of acute circulatory failure associated with inadequate oxygen utilization by the cells.

  • Pathophysiology:

    • Shock leads to cellular hypoxia, changing to anaerobic metabolism, and results in increased lactate levels.

    • As shock progresses: Red blood cells decrease, inadequate perfusion and worsened hypoxia occurs, and anaerobic processes increase leading to cell death.

Types of Shock

  • Compensated Shock:

    • Blood Volume Loss: 15-25%

    • Symptoms: Weakness, pallor, tachycardia, thirst, delayed capillary refill.

  • Decompensated Shock:

    • Blood Volume Loss: 30-45%

    • Symptoms: Hypotension (first sign of late shock), weak or absent peripheral pulse, prolonged capillary refill.

  • Four Types of Shock:

    • Hypovolemic Shock: Occurs due to low volume.

    • Distributive Shock (High Space Shock): Problem with the pipes.

    • Obstructive Shock: Blood flow is obstructed to the heart.

    • Cardiogenic Shock: Pump fails to circulate adequate blood (e.g., myocardial infarction).

Clinical Signs and Management

  • Hypovolemic Shock Early Symptoms:

    • Weakness, pallor, tachycardia, diaphoresis, low urinary output.

  • Hypovolemic Shock Late Symptoms:

    • Hypotension, altered level of consciousness, cardiac arrest.

Special Situations and Treatment Trends

  • Special Conditions:

    • Severe head injury hypovolemic shock - Fluid administration required to maintain cerebral perfusion.

Tranexamic Acid (TXA) Usage

  • TXA Functionality:

    • Stabilizes fibrin clots in trauma.

    • Should be administered early in bleeding trauma patients for effectiveness (less effective after 3 hours post-injury).