Shock

Definition:

It is characterized by low cardiac output (hypotension, decreased stroke volume) leading to decrease tissue perfusion.

Types of shock:

1.     Vasovagal shock:

It is characterized by increased activation of parasympathetic nervous system that will lead to bradycardia, decreased cardiac output, vasodilatation and shock. It can occur in fear, excitement and emotional trauma.

2.     Cardiogenic shock:

In this condition there is severe compromise of cardiac function occurring suddenly. The various causes are: 1) Myocardial Infarction 2) Arrhythmias 3) Trauma

3.     Hypovolumic shock:

It occurs in volume depletion e.g. Diarrhea, blood loss, burns etc

4.     Anaphylactic shock:

It occurs in severe reactions e.g. blood transfusion, bite of wasps, bee and snake.

5.     Septic shock:

It occurs due to septicemia (spreading of bacteria in the body through blood producing signs and symptoms).

Clinical features of shock:

Ø  Features common to all types of shock:

·         Blood pressure less than 100 mm Hg systolic.

·         Pulse is weak, thready and tachycardia

·         Skin is cold and clammy (wet)

·         Respiration is rapid

·         Oliguria: urine less than 30 ml/hour

·         Confusion and restlessness

Ø  In Cardiogenic shock:

·         Arrhythmias

·         Chest pain

Ø  Hypovolumic shock:

History of blood loss, diarrhea etc

Ø  Anaphylactic shock:

History of being bitten by insects, blood transfusion (mismatch) and drugs allergic reactions

Ø  Septic shock:

Pyrexia (fever)

Investigations:

Take proper history and examination. Then do the following investigation.

       I.            Full Blood Count (FBC):

In case of septicemia the Total Leukocytes Count (TLC) may be raised. In anaphylaxis the eiosinophils may be raised.

    II.            Urea / Creatinine, electrolytes:

They can tell you about the renal insult or damage, if urea, creatinine and electrolytes loss is raised in urine. 

 III.            ECG (Electrocardiogram):

It can tell you about the MI and arrhythmias.

  IV.            Prothrombin time (elongation), Activated partial Thromboplastin time

It is deteriorated in septic shock.

     V.            Arterial Blood Gases

It can tell you about O2 saturation.

Management of shock:

One should always try to identify the cause and treat it accordingly.

ü  Cardiogenic shock:

·         If myocardial infarction has occurred in less than 12 hours: I/V morphine, aspirin, streptokinase and defibrillation (shock) and may require dobutamine and dopamine

·         If arrhythmias then identify the arrhythmia and defibrillation

·         If heart block then pace makers are used.

ü  Vasovagal shock:

Usually they recover quickly; the management option includes pacemakers and beta blockers

ü  Hypovolumic shock:

·         Replace I/V fluids

·         In case blood loss replace with blood

ü  Anaphylactic shock:

In this the patient is given Anti-histamine and steroids

ü  Septic shock:

They are treated with broad spectrum antibiotics.