Shock Flashcards
What is shock using:
- SBP
- Mean arterial pressure (MAP)
<90
<65
What is shock?
What are the 3 types of shock?
Circulatory failure leading to low perfusion and thus tissue dysfunction due to hypoxia.
Distributive shock
Cardiogenic shock
Hypovolaemic shock
Stages:
Stage 1:
- There is obviously hypoxia. What may become raised in the blood due to anaerobic resp?
Stage 2:
- What are some compensatory mechanisms for the hypoperfusion? - 3
Stage 3:
- What type of acid-base imbalance occurs?
- What may be a sign it is getting worse?
Stage 4 - it is irreversible, they are unresponsive etc.
Lactate
Raised RR - more O2
Sympathetic response - Tachycardia, Fluid retention
Reduced fluid loss - Increased Renin and ADH
Metabolic acidosis - due to lactate formation
Altered mental status
Types and causes:
Hypovolemic shock (bleeding/fluid loss):
- Where can haemorrhage occur from?
- How else can haemorrhage occur in those who are of child-bearing age?
- What are some GI causes of shock?
- How can acute pancreatitis cause shock?
- What could cause fluid loss through the skin? - 2
Trauma
Ruptured AAA
Aortic dissection
Upper GI bleed
Ruptured ectopic pregnancy
D&V
Due to fluid sequestration
Burns and heat exhaustion
Types and causes:
Distributive shock:
- What does this mean?
- Neurogenic shock - how does CNS injury cause this?
- Spinal shock could also similar symptoms to neurogenic shock. What else would spinal shock cause?
Sepsis and anaphylaxis are types of distributive shock, though may also include an element of hypovolaemic shock as altered capillary permeability leads to volume loss from the vasculature.
Vasodilation leads to a relative
It reduces sympathetic tone there a drop in BP and HR
Spinal shock refers to a clinical syndrome characterized by the loss of reflex, motor and sensory function below the level of a spinal cord injury (SCI). In some instances (possibly when the lesion is T6 or higher), this syndrome is associated with loss of autonomic tone leading to hypotension, hypothermia and ileus.
Types and causes:
Cardiogenic shock:
- What causes primary pump failure? - 4
- What causes secondary pump failure due to impaired ventricular emptying and/or filling?
ACS
Myocarditis
Severe valve disease
Trauma
PE
Tension pneumothorax
Cardiac tamponade
Presentation:
What are some general signs of hypoperfusion? - 4
Distributive shock (sepsis, anaphylaxis, neurogenic) is characterised by vasodilation: - What signs would you see on the patient?
Cardiogenic, obstructive, or hypovolaemic shock leads to vasoconstriction.
- What signs would you see on the patient?
Pulse pressure is the difference between systolic and diastolic blood pressure. It is measured in millimetres of mercury (mmHg). It represents the force that the heart generates each time it contracts. Resting blood pressure is normally approximately 120/80 mmHg, which yields a pulse pressure of approximately 40 mmHg.
Is the pulse pressure increased/decreased in distribute shock?
Low BP
Oliguria <30ml/hr - <0.5ml/kg/hr
Tachycardia
Cap refill > 2 secs
Warm and sweaty (though maybe cold later)
Cold and clammy
Pulse pressure is wider due - narrow in the other types
Investigations:
Over what lactate level suggests hypoperfusion?
Do normal bloods and look for a cause!
> 2
Management:
Most respond to IV fluids in hypotension or blood products in haemorrhage!
What may be needed if they don’t respond?
What can be given in cardiogenic shock (basically heart failure) to relieve pain and anxiety?
Inotropes (strengthen the force of the heart beat) and/or vasopressors (cause vasoconstriction)
Diamorphine
Who should you call if there is no recordable BP?
Cardiac arrest team - 2222
Inotropes and vasopressors:
How do inotropes increase BP?
How do vasopressors increase BP?
What route is used? - not a catheter!
Increasing cardiac contractility
Causing vasoconstriction
Through a central line
Inotropes and vasopressors:
Noradrenaline:
- What is another name?
- This is the first line for shock in many ICU’s however adrenaline is preferred as it’’s cheaper and more available!
Adrenaline:
- What 2 emergencies is it used in?
- There are other agents but not commonly used!
What is a common vasopressor that is usually used?
Norepinephrine
Anaphylaxis
Cardiac arrest
Vasopressin
Inotropes and vasopressors:
Side effects:
- Extravasation is a risk of giving it peripherally. What is it and how does this carry risk?
- Where could they cause ischaemia?
Extravasation is the leakage of intravenously (IV) infused, and potentially damaging, medications into the extravascular tissue around the site of infusion.
It can cause tissue necrosis due to vasoconstriction
GI tract, kidneys, extremities
