Hypovolaemia and Hypovolaemic Shock Flashcards
What is hypovolaemia
A condition where blood volume is low
What cause hypovolaemia
Blood loss, severe dehydration, vomitting, diarrhea, fluid loss
Tissue perfusion
The delivery of O2 and nutrients to the tissue VIA blood supply
What are baroreceptors
Specialized cells that detect changes in blood pressure
What is hypovolaemic shock
A life threatening condition where blood volume is significantly low, leading to poor tissue perfusion
What are compensatory mechanisms that occur before shock
Increased HR to boost cardiac output
Vasoconstriction to redirect blood to vital organs
Activation of RAAS to elevate BP
Increased RR to increase O2 delivery
What happens to compensatory mechanisms during shock
Compensatory mechanism stay intact, but will slowly begin to fail if left untreated
What happens to BP if compensatory mechanisms fail
Hypotension - decreased blood pressure resulting in poor tissue perfusion
What is lactic acidosis
A condition where the blood pH is lowered by lactic acid
Why would anaerobic respiration kick in during hypovolaemic shock
Poor tissue perfusion means not enough O2 is being delivered to make ATP. Anerobic respiration doesn’t require O2
What is the downside of anaerobic respiration
Less energy is produced for vital organs, therefore they have less energy to carry out vital functions which can damage the organs
What does lack of O2 lead to
Cell damage and necrosis
Why would tachycardia get worse if compensatory mechanisms failed
The heart will continue to pump faster in response to the low blood volume, however cardiac output will slowly decrease
What would cause tissue hypoxia
Poor tissue perfusion as less O2 is delivered resulting in tissue hypoxia and eventually tissue damage
How does RR regulate blood pH
Chemoreceptors detect the low blood pH and cause the body to hyperventilate to try increase CO2 elimination
Why would HR be increased
Decreased blood volume cause the heart to pump more blood in an attempt to increase the volume
Why would BP be low
Reduced blood volume reduces blood flow, reducing blood pressureW
Why would RR be increased
Poor O2 delivery causes the body to increase O2 intake.
Why would the skin be cool and clammy
Vasocontriction would cause the body narrow the blood vessels in the skin as it tries to move blood to more important organs
Why would we monitor urine output
Urine output helps us access the hydration status of the patient
What would a low urine output signify
Dehydration as the RAAS activates to promote sodium and water retention
Why would we elevate the patient’s feet
To promote circulation and improve venous return to the heart using gravity
Why is it important for the patient to be mobile
Muscle movement helps push blood back into the heart
What are the risks of not elevating their feet
The patient will be more likely to throw a clot or get an oedema
How do IV fluids help hypovolaemic patients
IV fluids replace the lost fluid which can stabilize vitals, improve perfusion and restore imbalance
What is an IV crystalloid
A first-line treatment that helps replenish lost fluids and electrolytes
What is a IV colloid
Used for urgent cases to rapidly restore blood volume
What are IV colloids made of
Water and larger molecules like albumin
Why would we regulary weigh the patient
Weight loss can indicate fluid loss
What is the minimum urine output per hour
30ml
