Shock 

Description

Shock is a critical clinical state of circulatory failure resulting in inadequate tissue perfusion, cellular hypoxia, and potentially multi-organ dysfunction. It occurs when the circulatory system cannot deliver sufficient oxygen and nutrients to tissues to meet metabolic demands. Causes include hypovolemia, cardiogenic failure, sepsis, or anaphylaxis.

Types of Shock, Identification, and Key Features

1. Hypovolemic Shock

• Cause: Loss of blood (hemorrhage), plasma, or extracellular fluid (vomiting, diarrhea, burns)

• Identification / Clinical features:

  • Rapid, thready pulse

  • Low blood pressure

  • Cold, clammy skin

  • Oliguria/anuria

  • Confusion, restlessness, low GCS

  • History of trauma, bleeding, or fluid loss

• Investigations:

  • FBC (for anemia)

  • U&Es, Cr (for dehydration, renal perfusion)

  • Hematocrit and lactate

  • Coagulation profile if hemorrhagic

• Treatment:

  • ABC approach

  • Rapid IV fluid resuscitation with crystalloids

  • Blood transfusion if hemorrhagic

  • Colloids if indicated

  • Treat underlying cause (stop bleeding, replace fluids, manage diarrhea)

2. Cardiogenic Shock

• Cause: Primary heart failure (myocardial infarction, severe cardiomyopathy, arrhythmias)

• Identification / Clinical features:

  • Cold, clammy extremities

  • Weak, rapid pulse

  • Hypotension (SBP <90 mmHg)

  • Pulmonary congestion (dyspnea, crackles)

  • JVD (jugular venous distension)

  • History of cardiac disease

• Investigations:

  • ECG, cardiac enzymes (Troponin, CK-MB)

  • Echocardiography (EF, wall motion abnormalities)

  • FBC, U&Es, Cr, LFTs

  • Chest X-ray (pulmonary edema)

• Treatment:

  • Oxygen therapy

  • Avoid aggressive fluid loading (may worsen pulmonary edema)

  • Inotropes (e.g., Dobutamine, Dopamine) if hypotensive

  • Treat underlying cardiac condition (revascularization, anti-arrhythmics)

  • Vasopressors (e.g., Norepinephrine) if persistent hypotension

3. Distributive Shock

• Includes: Septic shock, anaphylactic shock, neurogenic shock

• Cause: Vasodilation and abnormal distribution of blood flow despite normal or increased cardiac output

• Identification / Clinical features:

  • Septic shock: Fever, hypotension, tachycardia, warm extremities, altered mental status

  • Anaphylactic shock: Sudden hypotension, urticaria, angioedema, respiratory distress, wheezing

  • Neurogenic shock: Hypotension with bradycardia, warm dry skin, spinal injury history

• Investigations:

  • FBC, U&Es, Cr, LFTs

  • Blood cultures (for sepsis)

  • Lactate level (marker of tissue hypoperfusion)

  • Imaging as indicated (CXR, CT if infection source suspected)

  • Allergy testing if anaphylaxis suspected

• Treatment:

  • ABC approach and oxygen therapy

  • Aggressive fluid resuscitation (crystalloids)

  • Vasopressors if persistent hypotension (Norepinephrine for sepsis)

  • Treat underlying cause:

    • Antibiotics for sepsis

    • Epinephrine for anaphylaxis

    • Steroids for specific indications

  • Monitor urine output, lactate, perfusion

4. Obstructive Shock

• Cause: Physical obstruction to cardiac output (pulmonary embolism, cardiac tamponade, tension pneumothorax)

• Identification / Clinical features:

  • Hypotension, tachycardia

  • Distended neck veins (JVD)

  • Dyspnea, hypoxia

  • Chest pain (PE or tamponade)

  • Tracheal deviation (tension pneumothorax)

• Investigations:

  • ECG, echocardiography (tamponade, RV strain)

  • Chest X-ray / CT scan

  • D-dimer if pulmonary embolism suspected

• Treatment:

  • ABC approach and oxygen therapy

  • Relieve obstruction urgently:

    • Needle decompression for tension pneumothorax

    • Pericardiocentesis for cardiac tamponade

    • Thrombolysis or embolectomy for massive pulmonary embolism

  • Supportive care with fluids and vasopressors if needed

General Principles of Shock Management

1. Early recognition and rapid intervention are critical

2. ABC approach

3. Fluid resuscitation:

   • Crystalloids first-line

   • Blood products for hemorrhagic shock

   • Avoid overloading in cardiogenic or obstructive shock

4. Vasopressors / Inotropes according to type of shock

5. Monitor and reassess:

   • Vital signs (BP, HR, RR, temp)

   • Perfusion (capillary refill, extremity warmth, mental status)

   • Urine output

   • Laboratory markers (lactate, FBC, U&Es, Cr)

6. Identify and treat underlying cause promptly

Key Points

• Shock is a life-threatening emergency.

• Type identification is critical for targeted treatment.

• Continuous monitoring of hemodynamics, perfusion, and organ function is mandatory.

• Early use of fluids, vasopressors, and definitive treatment of the underlying cause significantly improves outcomes.