Renal Replacement Flashcards
4 renal functions
excretory function
water and electrolyte balance
acid base balance
- compensate with ventilation partly
renal endocrine function
- erythropoietin – RBC
- calcium metabolism – vit D production of Ca Metabolism
- renin secretion
how are renal endocrine functions dealt with in renal failure
medically - with injections
how are renal excretory, water and electrolyte and acid base balance functions dealt with in renal failure
with renal replacement
what type of process is renal dialysis
passive
diffusion down concentration gradient
what does the dialysis machine facilitate in renal replacement
Allows intermittent correction of changes in plasma concentration of small molecules
Blood with desired and undesired components
- Thin membrane
Causing undesired to move out and more desired to move in
what impact does renal dialysis have on the pt lifestyle
significant restrictions remain
Not connected 24/7
- Stop dialysis get worse again
- Build up until plugged in again
- Tends to affect how pt feels - up and down
Keep blood at tip top all the time
- Better than no kidney function
- Any water that you take in as to go out through dialysis
Restricted in types can eat and fluid drink. As only up to limit by what is achieved by dialysis
where does haemodialysis occur
outside the body
where does peritoneal dialysis occur
inside the body
using peritoneum as dialysing machine
Peritoneum (gut bag), exposed thin layer of BV
- Machine into meet the blood rather than blood out to
what are the 2 types of dialysis
heamodialysis and peritoneal dialysis
what do you need to do to a body’s circulatory system to perform heamodialysis
Need to short circuit some body’s system so faster
- Pressure in artery high, vein low
- Lots of blood through loop
Vein increases
- Easier to out cannula in
- Suitable access point for dialysis
Undergo diffusion process in machine
what do you need to add to blood to prevent it clotting in the haemodialysis machine
heparin
so blood become anti-coagulated
- passes down through the dialyser
what is the dialyser tube like
Filled with tubes surrounded by dialyising solution
what do the thin membranes of the dialyser tube permit
thin membranes maximise area between dialysing solution and blood
what influences the time between dialysis and no dialysis in haemodialysis
Cycle of dialysis and no dialysis
Time between depends on kidney function level
- Can be overnight - infection control issue for haemodialysis
so less common
what additional modifications to you need on a haemodialysing machine so it works effectively
Heaters to warm up solution
Traps to prevent air in
pumps to keep pressure
heparin for anti-coagulation
what is a basic description of the process of dialysis
Purely passive diffusion down to concentration gradients between blood and dialysing solution
Effectively like clingfilm with tiny holes in it
- Depending on size of hole in that membrane
- Too large to let big ions through
Design membrane to allow electrolyte exchange, protein exchange
Design dialysing solution on one side to be what you want to achieve on the other (blood)
- Create a concentration gradient for ions to move in/or of blood
- Dialysing solution should be opposite of blood
- –High in solution - move in
- –Low in solution - move out of blood
how should you design the dialysing solution
Design dialysing solution on one side to be what you want to achieve on the other (blood)
- Create a concentration gradient for ions to move in/or of blood
- Dialysing solution should be opposite of blood
- –High in solution - move in
- –Low in solution - move out of blood
what should the dialysing solution be compared to blood
opposite of what you want the blood to be
peritoneal dialysis process
Surface of bowel loops hasn’t got epithelial covering on it
- Behave like dialysing straws -enough diffusion occurring
Fluid into peritoneum not machine
- Sealed bag with intestines on inside
- Tube in - fluid stay as sealed off
Stay around outside of gut loops
After a while chance to equilibrate
Inside body rather than outside in machine
Suck into drainage contained – back out
what is the tube like in the implanted catheter
like a leaky garden hose
where is the implanted catheter positioned
Positioned inside peritoneum
Bath peritoneal cavity
3 advantages of peritoneal dialysis
Different patterns to use
- Can do day and night
- Can do at side of bed - no blood tubes
- Can do only at night
Can do at home so can do every day
- Meaning no bad days
- Mimics more natural kidney condition
Machine can go in suitcase - All need bags of fluid - More flexible system - More able to travel and work Overnight dialysis
disadvantage of peritoneal dialysis
In charge of own life/death
- Lots of responsibility on pt - May dislike
disadvantage of haemodialysis
Cannot go away for a day
- Otherwise needs to go to a place where hospital able to do dialysis and spend lots of time on dialysis
what is the main drawback of both types of dialysis
Dialysis is not cure
- way of staying alive
Restricted to fluid that can take in (1l a day)
- Used for everyday - swallow, dry mouth restricted hydration and food intake level
Less so with peritoneal dialysis
how do you replace erythropoietin in renal failure
replaced by EPO injections
- maintains RBC mass
how do you ensure bone mass maintenance in renal failure
Vitamin D supplementation (stopped production)
Osteoporosis prevention programme
how do you control hypertension in renal failure
Renin-angiotensin system inactive (stopped renin secretion)
Ace inhibitors may have limited use
what is the next treatment step after dialysis
transplantation
why is dialysis not ideal for children
Dialysis will keep you ticking along
- But not support in growth
Issue in children
- Not puberty as normal
High priority for transplant
what is the optimal treatment for end stage renal disease
renal transplantation
what does renal transplantation restore
normal renal function
no dietary restrictions normal energy and fertility
why is there a waiting list for renal transplantations
Shortage of donor organs
- Usually trauma organs
May be family
- Don’t donate at beginning as increase with age less likely to get donation with age
Live donor more successful than deceased
is renal transplant a cure for kidney disease
no - temporary fix
Then need another transplant
- Less chance on second time of getting
Graph gets attacked by immune system and renal functions fail again
- Like chronic renal failure
Usually trauma organs
what happens to the non-functioning kidneys in renal replacement
left in - hard to access
where is the replacement kidney placed in the body
Put transplant in pelvis
Where appendix is
- Easy to connect to artery and ureter
Issue as vulnerable to contact sports
what has the better survival rate - renal dialysis or transplant
renal transplant
what are the 4 possible renal transplant problems
Rejection
- acute or chronic
- Immune system takes a dislike to it
immunosuppression
- increased infection/malignancy risk
high cardiovascular mortality
- ? An effect of transplant
- ? Aetiological in renal disease
Osteoporosis risk
how can renal transplant increase osteoporosis risk
Bone loss greater with time since transplant
- Manageable with mx
- vit D supplementation
what could be a reason for quick rejection of renal transplant
Can happen very fast
- —Identifies as foreign
- —Attacks and destroys it
what could be reason for long term rejection of renal transplant
Can happen over years
- Medication stops immune attacking new kidney
does a deceased or alive donor have increased survival chance for renal transplant
Less success rate from deceased donor
- 75% compared to 90%
Usually due to more time out of body so more time to be traumatised
dentistry and renal disease (5 factors)
treat after haemodialysis sessions
- not necessary for Peritoneal Dialysis patients
- Most able to accept tx
- But not on day - as anticoagulants so may effect tx
- —Best is day following dialysis session
liase with physicians for drugs
- DO NOT use the dialysis shunt - Patient’s lifeline!
- Medicine needs to be excreted in dialysis
need to be sure before give
speak to renal physician so doesn’t accumulate in the body
No heroic treatment plans
- Patient may not be able to cope with complicated treatment sessions
- Can it wait whilst they are on dialysis?
normal renal function at first may reduce with time
- Check creatinine levels
- Chronic renal failure
- —-Kidney function drops
complications are those of immune suppressants
steroid side effects
increased cancer risk
- be suspicious of oral mucosal lesions
