Chronic Renal Disease

Question 1

Current CKD definition?

Answer 1

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 2

Classification of chronic renal failure?

Answer 2

Stage 1: GFR> 90

2: 60-89
3a: 45-59
3b: 30-44
4: 16-29
5: <15

Question 3

How do we measure GFR?

Answer 3

Use serum creatinine to formulate an estimated GFR

Question 4

When will creatinine start to rise in serum?

Answer 4

When 60% of renal function is lost

Question 5

Why do black patients have a higher serum creatinine even at normal creatinine clearance ?

Answer 5

Higher muscle mass

Question 6

Other ways to assess if the kidney is filtering correctly?

Answer 6

Checking blood or protein in the urine - should be NONE

Question 7

Other ways to look at kidney function?

Answer 7

Looking at anatomy via radiography or histology

Question 8

Prevalence of CKD?

Answer 8

Increases with age

8-12% in UK

Question 9

Name some common causes of CKD.

Answer 9

DM

Hypertension

Question 10

Name some less common causes.

Answer 10

GN
Polycystic kidney disease
Pyelonephritis 
SLE
Myeloma and amyloidosis

Question 11

Relevent Hx from a CKD patient?

Answer 11

Past UTIs
Hypertension and DM
FHx
DHx
Ureamic symptoms

Question 12

Investigations for CKD?

Answer 12

Blood
Urine
Imaging

Question 13

What will x-rays help show?

Answer 13

If patient has renal osteodystrophy - pseudofractures

Question 14

What will you want to look for in urine?

Answer 14

PCR or ACR (protein/albumin creatinine ratio’s)

Blood

Question 15

What are uraemic symptoms?

Answer 15

Nausea, anorexia, vomiting
Pruritus
Weight loss
Weakness, fatigue and drowsiness

Question 16

What sort of drugs can cause CKD?

Answer 16

NSAIDs
Penicillins/aminoglycosides
Chemotherapeutic drugs
ACEIs/ARBs

Question 17

Why is ultrasound a good investigation?

Answer 17

Non-invasive
No ionising radiation
Can give information about disease/ if there is an underlying cause

Question 18

Negatives about the ultrasound?

Answer 18

Depends on how good the operator is and doesn’t have any functional data

Question 19

What are the main ways we slow the rate of renal decline?

Answer 19

BP control - high BP = faster rate of decline
Control proteinuria
Reverse contributing factors/treat causes

Question 20

List complications due to a low GFR.

Answer 20

Acidosis
Anemia
Bone disease
CV risk 
Death and dialysis
Electrolyte imbalance
Fluid overload
Gout
Hypertension

Question 21

When is metabolic acidosis seen ?

Answer 21

When GFR<20mls/min

Question 22

What does metabolic acidosis contribute to?

Answer 22

worsening hyperkalemia and renal bone disease

Question 23

How to treat metabolic acidosis?

Answer 23

Oral Na Bicarbonate

Question 24

When is anemia seen?

Answer 24

When GFR<20mls/min

Question 25

Why does anemia happen?

Answer 25

Renal disease causes reduced erythropoietin production and RBC survival

Question 26

Treating anemia?

Answer 26

Iron

ESA therapy -Erythropoietin stimulating agents

Question 27

Features of renal osteodystrophy?

Answer 27

Osteoporosis due to reduced bone density

Osteomalacia (softening of bone) due to reduced mineralization of osteoid matrix

Question 28

What causes renal osteodystrophy?

Answer 28

Reduction of GFR = hyperphosphateaemia

Loss of renal tissue = lack of activated Vit. D

Usually - Vit. D is activated by the enzyme 1α hydroxylase in the kidney but in CKD this enzyme is low

This leads to a reduction of calcium reabsorption

Question 29

Why does reduction of GFR = hyperphosphatemia?

Answer 29

The majority of phosphate that comes into the body is then excreted through the kidneys.

If the kidneys are not working so well phosphate will build

Question 30

What effect does low calcium and high phosphate have on the endocrine system?

Answer 30

Stimulates parathyroid glands to make more PTH - 2y hyperparathyroidism to try and correct imbalance

Prolonged secretion can cause 3y hyperparathyroidism

Question 31

What does a high phosphate do to the CVS?

Answer 31

Causes vascular and cardiac calcification

Question 32

What does a high PTH do to bones?

Answer 32

Increases activity of oesteoclasts and osteoblasts which increases bone turnover

Question 33

Management of renal bone disease?

Answer 33

Control phosphate via diet and phosphate binders

Normalise Ca and PTH - active Vitamin D analogues like calcitrol

If in 3y hyperparathyroidism - parathyroidectomy and calcimimetics

Question 34

What is a calcimimetic?

Answer 34

A drug that mimics calciums actions on body

Question 35

What causes hyperkalemia?

Answer 35

K+ is normally excreted by exchange with Na+ in distal tubule

But reduced GFR = reduced delivery of Na+ to distal tubule

Question 36

Acute hyperkalemia treatment?

Answer 36

Stabalise - calcium gluconate
Shift - salbutamol, insulin-dextrose
Remove - dialysis, calcium resonium

Question 37

Chronic hyperkalaemia treatment?

Answer 37

Diet and drug modifications

Question 38

What is fluid overload?

Answer 38

When you are unable to excrete excess Na+ load causing sodium and water retention —> oedema and hypertension

Question 39

Treatment for overload?

Answer 39

Sodium and fluid restriction

Loop diuretics

Question 40

What is the ideal BP in CKD?

Answer 40

Aim for <125/75 if sign proteinuria

If CDk with no proteinura - 130/80

Question 41

What needs to be considered about drugs/toxins in CKD?

Answer 41

Kidney cannot excrete drugs and toxins as well - beware antibiotics, morphine, digoxin, metformin

Question 42

What drugs can cause AKi on top of CKD?

Answer 42

Contrast agents

Antibiotics