Shock and hypovolaemia Flashcards
Describe the impact of trauma on the coagulation cascade
Trauma causes metabolic stasis, reducing perfusion to cells that provide energy; ATP pumps aren’t active so the mitochondria aren’t burning off substrates. They can’t produce heat and thermogenesis is compromised. People go cold (to ambient room temp) quickly , and at 35 degrees clotting factors are halved.
What is the volume, percentage, and symptoms of a class I haemorrhage?
- Up to 750mL
- 15%
- HR <100, normotensive, capillary refill <2, RR 14-20, normal mental state
What is the volume, percentage, and symptoms of a class II haemorrhage?
- 750-1500mL
- 15-30%
- HR >100, normotensive, capillary refill >2, RR 20-30, mildly anxious
What is the volume, percentage, and symptoms of a class III haemorrhage?
- 1500-2000mL
- 30-40%
- HR >120, hypotensive, capillary refill >2, RR 30-40, anxious and confused
What is the volume, percentage, and symptoms of a class IV haemorrhage?
- > 200mL
- > 40%
- HR >140, hypotensive, capillary refill >2, RR >35, confused/lethargic, will see peri-arrest symptoms
What is the definition of shock?
A state of poor perfusion where cellular oxygen demand is not by supply; metabolic stasis. This results in insufficient ATP generation, anaerobic metabolism, and cellular acidosis.
What is the Fick principle and what are the three steps?
- Loading of O2 onto RBC in lungs
- Delivery of oxygenated RBC to tissue cells
- Offloading of O2 from RBC to tissue cells
What are the causes of hypovolaemic shock?
- Haemorrhage
- Dehydration
- Severe burns
- DKA
- Sweating
- Peritonitis
What is the ‘third space’?
Space in the body where fluid does not normally collect or where any collection is physiologically non-functional
What is the definition of hypovolaemic shock?
Insufficient circulating volume
What is the definition of cardiogenic shock?
Failure of the heart to pump effectively
What are the causes of cardiogenic shock?
- CA
- MI
- Arrhythmias
- Cardiomyopathy
- Congestive heart failure
- Valve issues/rupture
What is the definition of obstructive shock?
Mechanical block to hearts’ outflow
What are the causes of obstructive shock?
- Pulmonary embolus
- Cardiac tamponade
- Tension pneumothorax
What is the definition of distributive shock?
‘Relative hypovolaemia’ - dilated blood vessels.