Lecture Notes on Shock

Definition and Importance of Shock

• Shock is a severe medical condition defined as inadequate cellular perfusion, where body cells are deprived of oxygen, blood, and nutrients.
• Hypoperfusion: This is the process where the body doesn't receive enough oxygen to cells, leading to shock.
• Good perfusion requires:
  • A properly functioning heart as a pump.
  • Blood vessels that are appropriately constricted or dilated.
  • Sufficient and healthy blood volume.

Types of Shock

1. Cardiogenic Shock

• Caused by pump failure.
• Main causes:
  • Heart attack (myocardial infarction).
  • Diseases like congestive heart failure (CHF).
• Symptoms include:
  • Pulmonary edema: fluid in alveoli leading to poor gas exchange.
  • Orthopnea and jugular venous distention (JVD).
  • Decreased cardiac output.

2. Obstructive Shock

• Circulation is obstructed by physical blockage.
• Main emergencies causing it:
  • Cardiac tamponade: fluid around the heart.
  • Tension pneumothorax: air around collapsed lung.
  • Pulmonary embolism: blockage in pulmonary artery.

3. Distributive Shock

• Characterized by vasodilation.
• Four subtypes:
  • Septic shock: widespread infection, e.g., from pneumonia or UTI.
  • Anaphylactic shock: severe allergic reaction affecting multiple body systems.
  • Psychogenic shock: caused by emotional events, leading to fainting.
  • Neurogenic shock: result of severe trauma to the spinal cord.

4. Hypovolemic Shock

• Due to low blood volume:
  • External or internal bleeding.
  • Severe dehydration.
  • Medical terminology: "hypo" (low) "volemia" (volume).

Stages of Shock

• Compensated Shock: Body tries to maintain function with increased respiration and heart rate.
• Decompensated Shock: Physiological systems fail, leading to hypotension and unresponsiveness.
• Irreversible Shock: Critical state where recovery is unlikely.

Treatment of Shock

• Treatment depends on the type of shock:
  • Cardiogenic shock: Address the heart issue.
  • Anaphylaxis: Use an EpiPen.
  • General rule: Identify the type and cause, then apply the appropriate treatment plan.

Importance of Early Recognition

• Early detection and treatment can prevent progression from compensated to irreversible shock.

Study Resources

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