Shock - With a focus on trauma Flashcards
What is shock ?
Shock is defined as a reduced delivery of oxygen to the tissues and/or the impaired cellular utilisation of oxygen.
What conditions can cause a pre-load deficinecy ?
Tension Pneumothorax.
Haemorrhage
Fluid loss
What is Sepsis ?
What is septic shock ?
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection
Septic shock should be defined as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone. In Practice- Not fluid responsive Sepsis
What is the pathophysiological response to blood loss?
What three receptors are involved in this mechanism?
FIRST - Baroreceptor reflex. Your baroreceptor reflex is a series of quick actions your body takes to keep your blood pressure in a normal range in response to an abrupt change in position – maintain BP with up to 15% blood loss.
SECOND - Cardiac C fibres. Stimulated by deformity of the ventricle
This leads to vagal-induced bradycardia & loss of sympathetic tone (particularly in skeletal muscle & kidneys)
Net loss in BP and bradycardia
3RD - Arterial chemoreceptors - In response to hypoxia. This leads to increased RR and vagally induced bradycardia and vasoconstriction in tissues such as skeletal muscle. This minimises the fall in BP from the C fibre reflex
What fluid should be used in Major Haemmorhage protocol?
Red cells - 4 units - optimise oxygen delivery.
FFP - 4 units
Don’t give fluid as it can dilute clotting factors.
What difference does it make if there is a blunt trauma vs a penetrating injury?
?? look back over this.
Barcroft -edholm reflex.
Blunt trauma afferents run in nociceptive fibre:
Reduces the baroreceptor sensitivity (less tachycardia with moderate loss). Occurs within 3 hours and lasts over 14 days (for a leg #).
Alcohol – enhances the fall in baroreceptor sensitivity seen in injury
Impaired the C fibre reflex (I.e. the one suppressing the rise in BP and reducing HR) this allows the raised BP to be maintained (along with tachycardia).
How do you approach a patient who is at risk of hypovalemic shock?
What are these symptoms a sign of?
Shocked/low BP
Distended neck veins
? Muffled HS ? Inaudible
High RR
Unilateral reduced AE
Hyper resonant unilaterally
Deviated trachea
Tension Pnuemothrax
What are the four types of shock ?
What is Hypovolemic shock?
What can cause it?
What symptoms would you see?
Loss of circulating volume
whether it be blood, plasma or
extracellular fluid.
What is Cardiogenic shock?
What causes it?
What symptoms would you see?
What is obstructive shock?
What causes it?
What signs and symptoms would you see?
What is Distributive shock?
What are the types of distributive shock?
Explain what neurogenic shock is.
What type of shock is it ?
A type of distributive shock
What is Becks triad ?
What does it suggest ?
Low BP
Distended neck veins
Muffled heart sounds
CARDIAC TAMPONADE.
NB Supporting history of cardiac surgery/instrumentation, penetrating trauma
At what level of spinal cord injury is more likely to cause nuerogenic shock ?
Because sympathetic innervation of the heart is associated with the T1-T5 levels of the spinal cord, neurogenic shock is most common in individuals with T6 or higher level spinal cord injuries.
This is due to disruption of the sympathetic nervous system and causes hypotension, bradycardia, and hypothermia.
What is the difference between spinal chock and neurogenic shock ?
Spinal Shock - Absence of all voluntary reflexes below the level of injury.
Neurogenic shock - Loss of vasomotor tone ( Hypotension, bradycardia and poikilothermia).
What is the most common cause of Low BP in neurogenic shock ?
Missed hypovalemic shock
How would you treat nuerogenic shock?
What is the treatment for Sepsis?
