Physiology of shock Flashcards
What is shock?
Shock is inadequate perfusion leading to inadequate oxygen delivery and eventually organ failure
What causes shock?
Either a problem with the heart, blood vessels or the flow of blood
Name the 5 types of shock
Cardiogenic, neurogenic, septic, anaphylactic and hypovolaemic
What is distributive shock?
Distributive shock is an umbrella term for septic, anaphylactic and neurogenic shock. There is sufficient fluid but it is in the wrong place
What is the key issue in hypovolaemic shock?
Loss of intravascular volume
In which kind of shock is heart failure the key issue?
Cardiogenic shock
What is the key issue in septic shock?
Toxins and malfunction at the capillary level
In which type of shock is mast cell degranulation the key issue?
Anaphylactic shock
What is the key issue in neurogenic shock?
Loss of sympathetic outflow in thoracic spine leading to lack of feedback
How does neurogenic shock differ from the other types of shock in terms of heart rate?
Neurogenic shock causes bradycardia, every other type of shock causes tachycardia
How would you treat hypovolaemic shock?
Fluid and blood replacement
How would you treat cardiogenic shock?
Careful fluid management, ionotropes e.g. dobutamine, vasopressor drugs e.g. noradrenaline
How would you treat septic shock?
Sepsis 6 (BUFALO) and vasopressor if fluid unresponsive
How would you treat anaphylactic shock?
Adrenaline is first line treatment
How would you treat neurogenic shock?
Vasopressors
What is meant by cardiac arrest?
It does not necessarily mean the heart has stopped beating, it means that cardiac output is not sufficient for a palpable carotid pulse
What are the reversible causes of cardiac arrest?
4 Hs - hypovolaemia, hypoxia, hypothermia and hyperkalaemia
4 Ts - toxins, thrombus, tension pneumothorax and cardiac tamponade
In which cardiac arrythmias is immediate defibrillation appropriate?
Ventricular fibrillation and pulseless ventricular tachycardia
What is the more popular theory as to why CPR works?
It changes the intra-thoracic pressure and creates a gradient for blood flow to continue
