Chapter 13: Shock

Overview

• Understanding of different types of shock
• Process of perfusion
• Signs and symptoms of shock
• Assessment process for shock patients
• General and specific emergency care for shock patients

Shock and Perfusion

• Shock: Also known as hypoperfusion; inadequate cellular perfusion.
  • Can lead to cellular injury or death.
  • Early stages: Body attempts to maintain homeostasis.
• Diffusion: Movement of molecules from high to low concentration (e.g., oxygen and carbon dioxide across alveoli).
• Transport of Carbon Dioxide: Dissolved in plasma, combined with water to form bicarbonate, or attached to hemoglobin.
• Collapse and Failure of Cardiovascular System: Leads to inadequate circulation.
  • Blood is redirected from tolerable low-flow organs (skin, intestines) to vital organs (heart, brain, lungs).

Recognition and Treatment

• Early recognition of shock symptoms is crucial.
• Shock requires immediate recognition and treatment.

Cardiovascular System Components

• Three Parts: Heart (pump), blood vessels (container), blood (contents).
• Perfusion Triangle: Heart, blood vessels, blood.
• Blood Pressure: Pressure of blood within vessels at any moment.
  • Systolic Pressure: Peak arterial pressure during heart contraction.
  • Diastolic Pressure: Pressure in arteries while the heart is resting.
  • Pulse Pressure: Difference between systolic and diastolic pressure.

Regulation of Blood Flow

• Capillary Sphincters: Regulate blood flow through capillary beds.
  • Controlled by the autonomic nervous system.
• Autonomic Nervous System and Hormones: Support respiratory and cardiovascular systems during increased perfusion needs.
  • Sympathetic Nervous System: Takes over in shock, releasing epinephrine and norepinephrine.

Causes of Shock

• Pump Failure: Cardiogenic and obstructive shock.
• Poor Vessel Function: Distributive shock (septic, neurogenic, anaphylactic, psychogenic).
• Low Fluid Volume: Hypovolemic shock (hemorrhagic and non-hemorrhagic).

Types of Shock

• Cardiogenic Shock: Due to inadequate heart function or pump failure.
  • Causes: Heart failure, heart attack.
  • Symptoms: Pulmonary edema, low cardiac output.
• Obstructive Shock: Mechanical obstruction of blood flow.
  • Includes cardiac tamponade, tension pneumothorax, pulmonary embolism.
• Distributive Shock: Widespread dilation leading to pooling of blood.
  • Septic Shock: Caused by severe infection.
  • Neurogenic Shock: Spinal cord injury leading to vessel dilation.
  • Anaphylactic Shock: Severe allergic reaction.
  • Psychogenic Shock: Sudden nervous system reaction causing vascular dilation.
• Hypovolemic Shock: Inadequate fluid volume in the circulatory system.
  • Can result from thermal burns, hemorrhage.

Stages of Shock

• Compensated Shock: Body compensates for hypoperfusion.
• Decompensated Shock: Advanced stage with significant impairment.
• Irreversible Shock: Beyond the point of recovery.

Assessment and Treatment

• Scene Size-up: Ensure safety, determine mechanism of injury.
• Primary Assessment: Rapid exam, determine life-threats.
• History Taking: Obtain SAMPLE history.
• Secondary Assessment: Physical exam, vital signs.
• Reassessment: Monitor vital signs, interventions.

Emergency Care

• General Shock Treatment:
  • Control external bleeding.
  • Ensure open airway.
  • Provide high-flow oxygen.
  • Maintain body temperature.
  • Position patient in supine position.
  • Prompt transport.
  • Use advanced life support when necessary.

Specific Treatment Guidelines

• Cardiogenic Shock: Avoid nitroglycerin if hypotensive; provide oxygen.
• Obstructive Shock: High-flow oxygen, rapid transport.
• Septic Shock: High-flow oxygen, manage ventilation.
• Neurogenic Shock: Manage airway, support circulation.
• Anaphylactic Shock: Administer epinephrine, oxygen.
• Psychogenic Shock: Assess for injuries, monitor closely.
• Hypovolemic Shock: Control bleeding, maintain airway, rapid transport.

Special Considerations

• Older Patients: More serious complications, medication effects.
• Pediatric and Geriatric Treatment: Inline spinal stabilization, maintain comfort, rapid transport.

Conclusion

• Shock is a critical and life-threatening condition requiring immediate attention.
• Recognition and early intervention are crucial for patient outcomes.