Renal Medicine 2

Question 1

name the functions of the renal system

Answer 1

• Excretory function
• Water and electrolyte balance
• Acid base balance
• Renal endocrine function
	○ Erythropoietin 	
	○ Calcium metabolism 
	○ Renin secretion

Question 2

how is renal endocrine function treated

Answer 2

medically

- treated by managing blood pressure in other ways by giving patients supplements and injections

Question 3

what is renal dialysis

Answer 3

• A passive process
Diffusion across concentration gradients
Allows intermittent correct of changes in plasma concentration of small molecules
Not true renal replacement

Question 4

why is renal dialysis not true renal replacement

Answer 4

○ Significant lifestyle restrictions remain
§ Restricted in how much they can eat / drink / how much fluid and salt they can take in
§ Can only take in up to the limit of what can be achieved by dialysis

• Doesn’t restore normal kidney function as it cannot maintain what the kidney’s do constantly
Better than having no kidney function but really just keeps you ticking along

Question 5

what are the 2 types of renal dialysis

Answer 5

• Haemodialysis
○ Outside the body

• Peritoneal dialysis
Inside the body

Question 6

how does dialysis work

Answer 6

• Like clingfilm with tiny holes in it
  ○ Blood on one side
  ○ Solution on one side
  ○ Determines what passes through
• Design membrane to allow electrolyte exchange but not allow protein or cellular exchange
• Solution on one side of the membrane is designed to have what you want to achieve in the blood

Eg if there is a high potassium level in the blood then you want the potassium to leave so make the concentration of potassium on low to create a concentration gradient and the potassium will diffuse

Question 7

what happens in haemodialysis

Answer 7

• Hollow fibre dialysis
  ○ Blood passes down little straw like tubes to the bottom
  ○ These straw structures are surrounded by dialysing solution
  ○ Ensures the blood is constantly changing so there is a changing concentration gradient occurring as the dialysis occurs
• Blood has to go around this several times before you have the electrolyte balance where you want it to be
  A dialysis session can take 6-8 hours

Question 8

how does a typical haemodialysis cycle affect the patient

Answer 8

have the dialysis one day
then have a good day
then have a bad day
then back to having dialysis

• When the dialysis stops, your electrolyte and fluid balance is where you want it to be
  ○ Then the stuff you don’t want starts to build up so
  ○ Cannot lose what you don’t want
  Cannot gain what you do want
  = bad day

Question 9

how does peritoneal dialysis work

Answer 9

• Works in the same way as haemodialysis
  ○ The thin walls of the blood vessels behaves like the dialysing straws as diffusion can happen here to maintain the balance
  ○ Happens inside the body instead of inside the machine
• The dialysing solution is the opposite of what you want the blood to be?
• Fluid goes into peritoneum (this is separated by the pelvis and internal organs as a little organ)
  ○ Peritoneum is a big bag that holds the guts after you pass the layers of skin, fat and muscles
  ○ It is a sealed bag that has the intestines inside
  ○ Put fluid into this bag and it won’t go anywhere else in the body - will remain within the gut loops
  § Remove the fluid when finished
  § Replace fluid

Question 10

what are the steps in the exchange procedure of peritoneal dialysis

Answer 10

1. connect y system (double bag to Tenckhoff catheter
2. drain out from patient
3. drain from bag
4. fill abdomen
5. disconnect

Question 11

what role does an implanted catheter play in peritoneal dialysis

Answer 11

• When want to do dialysis = put the dialysing fluid in to the peritoneum
• When you want to stop the dialysis = suck the dialysing fluid out of the peritoneum

a valve below the surface of the skin with the tube positioned around inside the peritoneum

Question 12

what are the advantages and disadvantages of peritoneal dialysis

Answer 12

> more flexible
- can have lots of different time patterns for when the dialysis occurs
- can go on holidays more easily
wont have the same good and bad days as haemodialysis, can be much more consistent in how they feel

> patients don’t like being responsible for their own like and death

Question 13

what are the disadvantages of haemodialysis

Answer 13

> not flexible

• can only really go away for a day or so
• strict pattern

Question 14

what does dialysis restore

Answer 14

• Excretory function
• Water and electrolyte balance
• Acid base balance

Question 15

is dialysis a cure?

Answer 15

no

○ Limited to a litre a day
§ Used for everything you swallow
○ Can cause problems with dry mouth and paste issues
§ Due to issues with hydration
○ Restricts what they can eat
§ Avoid high salt contents
[these problems are more likely with haemodialysis than peritoneal dialysis]

more of a temporary treatment as a transplant is the most preferred treatment option

Question 16

is dialysis suitable for children

Answer 16

no
does not support them during growth
children are high priorities

Question 17

how is erythropoietin replaced in renal endocrine replacement

Answer 17

Replaced by EPO injections

Maintains red cell mass

Question 18

how is bone mass maintained in renal endocrine replacement

Answer 18

Vitamin D supplementation

Osteoporosis prevention programme

Question 19

how is hypertension controlled in renal endocrine replacement

Answer 19

Renin-angiotensin system inactive

Ace inhibitors may have limited use

Question 20

what is the advantage of renal transplantation

Answer 20

Optimal treatment for end stage renal disease
Normal renal function
No dietary restrictions
Normal energy and fertility

Question 21

why is transplantation not a cure

Answer 21

§ Temporary fix as a transplant won’t last more than 10-15 years and then you will need to get another transplant
§ Each time you get a kidney, there is less chance of getting another
§ A transplant is kind of like having chronic renal failure- When it fails you need another transplant

Question 22

what is a problem with renal transplantation

Answer 22

shortage of donations
younger patients get priority
as you get older you are less likely to receive one

Question 23

how is the transplant kidney inserted

Answer 23

the broken kidneys arent removed
the working kidney is usually put in the pelvis so it sits at the appendix in addition to the 2 not working kidneys

the new kidney is not as well protected so it is more vulnerable to be damage
contact sports are avoided

Question 24

what are the problems that arise with transplants

Answer 24

• Rejection - acute or chronic
○ Complicated - can either happen very fast or can happen over many years

• Immunosuppression
○ Increased infection / malignancy
○ Patients take medication to reduce the immune system attacking the transplant organ
○ This means the immune system is prevented from recognising infections and cancer cells § There is a higher risk of undetected serious infections and cancers that otherwise would be removed by the immune system

• High cardiovascular mortality
○ ? An effect of transplant
○ ? Aetiological in renal disease

• Osteoporosis risk

Question 25

is a kidney from a living donor better than a kidney donated from a deceased donor

Answer 25

yes

kidneys from a living donor tends to be in better condition and be less abused

Question 26

what should be done about dental treatment with regards to renal dialysis

Answer 26

• Treat after haemodialysis sessions
○ Want to treat patient when they are most able to take the treatment
§ Cannot happen on the same day as the dialysis
§ Needs to happen the day after for best results
§ Cannot do treatment a couple of days after dialysis as this will be the patient’s bad day
○ Not necessary for peritoneal dialysis patients

• Liaise with physicians for drugs
○ Medicine will ne to come out through dialysis
○ Speak with professional before prescribing anything
○ Need to be careful

• Do not use the dialysis shunt
○ Patient’s lifeline
○ If you need a blood sample or need to do an injection never use the dialysis shunt or arm
§ If this gets an infection can cause big problems

• No heroic treatment plans
○ Patient may not be able to cope with complicated treatment sessions
○ Fancy complex treatments are not a good idea
○ Restricted to what needs to be done

Question 27

what should be done with dentistry treatment / relevance with regards to renal transplant

Answer 27

• Normal renal function at first
○ Should be able to manage the patient normally at beginning
• May reduce with time
○ Check creatinine levels
○ Over time can develop chronic renal failure and the kidney function will drop and problems can come back into play again

• Complications are those of immune suppressants
○ Eg steroids
○ Potential risk of head and neck cancers being greater

• Drug interactions and complications
	○ Prednisolone 
	○ Azathioprine 
	○ Tacrolimus 
	○ Cyclosporin
	○ Drugs vary from person to person

• Steroid side effects

• Increased cancer risk
Be suspicious of oral mucosal lesions