Week 2 Revision Flashcards
How many L of the body of water?
40L (60%)
What is the systemic response to surgey?
To preserve fluid balance, blood volume and blood pressure
What are the 3 stages of responsde to surgery?
Stage 1 - fluid retention & catabolism
Stage 2 - diuresis
Stage 3 - anabolism
Explain how fluid loss is reduced by the renin-aldosterone-angiotensin system
1) the liver produces angiotensiogen
2) angiotensiogen is converted by renin to angiotensiogen 1
3) it then travels through the lungs and is converted to angiotensiongen 2 by converting enzymes
4) this is then converted in adrental cortex to release aldosterone which causes the reabsorpotion of the sodium; which then reduces fluid loss
Explain 3 functions of angiotensiongen 2
1) Vasopressin (enocurges the kidney to keep water, reduction of urine output)
2) Makes you thirsty (this will then increase fluid intaek, increasing blood flow)
Why will the renin-aldosterone-angiotensin system be activated? Give 3 reasons
- If sodium chloride levels drop
- Reduction in blood volume
- BP goes down
Why do you want to avoid surgical stress?
Fluid balance and BP will go crazy
List 4 immediate or early post operative complications?
- Haemorrhage
- Low urine output (AKI and dehydration)
- DVT (due to the lack of mobilisation)
- Acute confusion
What is shock?
Very suddenly the circulation of blood has a stopped flowing
What are the five types of shock? Explain
Cardiogenic – cardiac function (the heart) is not pumping effectly – mainly caused by a heart attcack. If the ehart is not piumping no blood getting aorund the body
Sepsis – caused by a body wide infection, you get vasodilation. BP drops
Anaphylasctic – huge vasodilation – you have a wide spread hyposensitivy reaction leading to wide spread vasodilation
Neurogenic – some damage above T6 in the spinal cord. Damage to the top of the spinal. Huge vasodilation. Huge trauma – RTC, a big fall
All these have no reduction in blood flow
Hypovolaemic shock – low volume of blood. Major reseason is because of bleeding
How much of blood loss will cause:
1) major threat
2) clinical shock but can be treated, is not life-threatening
3) severe, irreversible shock
1) 10% or less
2) 20-30%
3) 30-40%
What is hypovolaemic shock? What are 4 possible causes?
- Acute loss of 15-20% of blood volume (losing whole blood)
- haemorrhage (loss of whole blood)
- Burns (loss of plasma)
- large swetting
- emesis (vommiting)
What are the two stages of shock? Explain
1) compensation - the body is trying to help to do something about the loss of blood volume
2) decompensation - the shock has gone too far that it can not be help
How do you work out the cardiac output?
Heart rate x stroke volume (average 70mls)
What is peripheral resistance?
The resistance the blood encounters in the blood vessels (friction)
What is the arteriolar radius?
The radius of the blood vessels becoming larger to reduce friction when the blood flow is high, and getting smaller when the blood flow is low
What is the circulatory response to a reduction in blood volume?
1) bleeding occurs, resulting in a reduction in blood volume
2) venous return decreases as there is less blood going back into the right side of the heart
3) this will then reduce the amount of blood availble for the heart - reduced blood to the lungs, reduced oxygenation = reduced oxygen saturation
4) the contractions of the heart will slow down
5) stroke volume reduces - cardiac output reduces
If blood pressure was the be measured at this point, blood pressue would be low
In circulatory response to a reduction in blood volume, what occurs after the blood pressure drops?
1) decreased blood pressure is detected by baroreceptors. They send messages to the cardiovascular centre in the brain. The autonomic nervous system is activated via the sympathetic nervous system
2) The heart then begins to contract more. Arteriolar and venous constriction both occur
3) cardiac output, peripheral resistance and venous return are increased.
4) blood pressure then comes up
What is the decompensation stage of shock?
This is blood volume loss of more than 30% and fluid replacement is delayed
Blood pressure drops, blood flow to the heart and brain are restricted.
Fluid leaves the capillaries - decreased volume of blood and lowered blood pressure
celllar damage occurs > mutiple organ dysfunction system
List five fucntions of the kidneys
Regulate blood pH Regulate fluid balance Elimination of medication Controlling BP Removal of waste products
What two things are done to mange shock? Explain
colloid > bloods
Crystalloids > saline and hartmans
What is AKI?
a rapid reduction in kidney function resulting in the kidneys not being able to carry out their functions
What are the 3 different causes of AKI?
1) Fluid responsive > drop in blood delivery to the kidneys
2) Intrinsic > direct damage to the kidneys by inflammation, kidney stones or bladder trumor
3) Postrenal > a obstriuction to urine flow in the uteters, urethra and bladder
What two response’s to AKI?
1) hypovolaemia
2) hypotension
