Chronic Kidney disease

Question 1

Which 3 things do we assess for kidney disease?

Answer 1

Filtration (excretory) function – remove excess toxins + fluid

Filtration (barrier) function

Anatomy – abnormalities ie polycystic kidney

Question 2

When will Creatinine increase above normal range?

Answer 2

When more than 60% of total kidney function is lost

Question 3

Which isotope is used to measure renal function? How is it measured?

Answer 3

Chromium EDTA

Take a blood sample after giving patient isotope - test to see how the patient is clearing the isotope.

Question 4

Which renal function test is pretty much impossible in the elderly population?

Answer 4

24 hour urine collection plus blood test - trying to get samples over 24hrs from a frail, elderly patient is not easy

Question 5

What is most commonly used to measure excretory renal function?

Answer 5

GFR estimating equations

Question 6

What does Creatinine rely on?

Answer 6

Creatinine is dependent on muscle mass - this varies a lot between different patients

Also depends on:
Age
Ethnicity - African Americans have higher serum creatinine 
Weight
Gender
Other issues e.g liver disease

Question 7

What is the most commonly used formulae to estimate GFR?

Answer 7

MDRD 4 variable equation

Question 8

Why are the current formulae not very reliable?

Answer 8

They cannot give an accurate value for the GFR if it’s higher than 60

Question 9

Stages of chronic kidney disease

Answer 9

Stage 1 Kidney damage/normal or high GFR
Stage 2 
Stage 3a - moderate
Stage 3b - moderate
Stage 4 - severely impaired
Stage 5 - advanced or on dialysis

Question 10

How do we assess the kidney filtering function?

Answer 10

Urine dipstick - shouldn’t be any blood or protein if filtering properly

Send away for protein quantification - protein creatinine ration (PCR) - to see how much the kidneys are leaking

Question 11

Current definition of chronic kidney disease

Answer 11

Chronic kidney disease (CKD) is defined by either the presence of kidney damage (abnormal blood, urine or x-ray findings) or GFR<60 ml/min/1.73m2 that is present for ≥3 months

Question 12

Aetiologies of CKD

Answer 12

Diabetes
Glomerulonephritis
Hypertension
Renovascular disease - narrowing of one or both arteries leading to the kidneys
Polycystic kidney disease

Question 13

What are 2 common causes of CKD in the younger populations

Answer 13

Glomerulonephritis or polycystic kidney (genetic)

Question 14

Is CKD symptomatic?

Answer 14

More often than not CKD is asymptomatic with no signs until things are very advanced

CKD is often picked up incidentally

Question 15

Which 4 investigations are often done for CKD

Answer 15

Blood tests
Urine test
Radiology - USS

Biopsy - reserved for difficult cases where clinicians are unsure of what is going on

Question 16

Which blood tests are commonly done for CKD detection

Answer 16

U&Es

FBC

Question 17

Which types of urine tests are done for CKD detection

Answer 17

Urine dipstick
Urine PCR or ACR (protein or albumin creatinine ratio) - tend to do PCR in pregnant women
24 hour collection

Question 18

Why are blood tests done for CKD

Answer 18

Myeloma (bone cancer) can present with deteriorating kidney function – want to look for this in blood tests

Also want to check for anaemia

Question 19

What is ACR

Answer 19

Albumin creatinine ratio

Question 20

What are the only signs renal disease may show

Answer 20

Abnormal BP

Abnormal Urinalysis

Question 21

What management is in place to slow the rate of renal decline

Answer 21

BP control - v important

Control proteinuria

Treat underlying cause

Question 22

What classes of drugs are often used to control proteinuria

Answer 22

ACE inhibitors or ARBs

Question 23

Complications associated with a reduced GFR

Answer 23

Acidosis
Anaemia
Bone disease
CV risk 
Death & Dialysis
Electrolytes
Fluid overload
Gout
Hypertension
Iatrogenic issues

As kidney function drops below about 30 these complications become more prevalent

Question 24

Management of anaemia related to reduced GFR

Answer 24

Epoetin alfa - injectable drug

Iron

Question 25

What is the most important complication to try and prevent in order to help kidney function

Answer 25

Cardiovascular risk - BP, aspirin, cholesterol, exercise, weight, smoking cessation

Question 26

How do doctors prepare a patient for end stage renal disease and renal replacement therapy?

Answer 26

Education & information

Selection of modality
- HD / PD? transplant ?conservative care?

Planning access – fistula (needs to be in place for 6 weeks before it can be used)

Deciding when to start renal replacement therapy

MDT approach

Question 27

How does Chronic Kidney Injury cause Anaemia?

Answer 27

The kidneys make an important hormone called erythropoietin (this travels to the bone marrow, where it works to stimulate stem cells to become RBC’s)

Injury to the kidneys results in low EPO levels and as a result your RBC count drops