Lecture 20 - CKD

Question 1

Adult polycystic kidney disease

Answer 1

Autosomal dominant
PKD 1 and 2 gene

Renal cysts develop with age
Diagnosed with USS

Question 2

Secondary complications of renal cysts

Answer 2

Pain
Infection
Bleeding into cyst 
Renal stones - stasis 
Hypertension

Question 3

Management of APCKD

Answer 3

Treat hypertension - ACE inhibitors to block RAAS

Diet:
Drink water - flushing
Low salt
Normal protein intake

Tolvaptan - ADH antagonist

Question 4

Tolvaptan

Answer 4

ADH antagonist

Question 5

Normal GFR

Answer 5

90 - 120 ml/min/1.73m^2

Question 6

CKD

Answer 6

Irreversible and progressive loss of renal function over a period of months to years

Question 7

Why does renal injury cause CKD?

Answer 7

Renal injury causes renal tissue to be replaced by ECM

- glomerulosclerosis and tubular intersitital fibrosis

Question 8

CVS complications

Answer 8

Stroke
Vasculitis
MI

Question 9

Incidence of CKD

Answer 9

Prevalent in

• elderly
• ethnic minorities
• social deprivation
• multi morbidities
• FHx stage 5 CKD

Question 10

CKD macroscopic changes

Answer 10

Scarring - fibrosis

Loss of cortex

Question 11

Caused of CKD

Answer 11

Diabetic nephropathy
Hypertension 
Pyelonephritis
Renal vascular disease
Glomerulonephritis - rare 
APCKD
Myeloma

Question 12

Investigations of CKD

Answer 12

Blood pressure
Urine dipstick 
GFR
Blood tests 
USS 
Kidney biopsy

Question 13

CKD staging

Answer 13

1 - eGFR - greater than 90 with proteinuria/haematuria

2. eGFR 60-90 - proteinurian and haematuria
3. eGFR 30 - 60
4. eGFR 15 - 30
5. eGFR less than 15 = ESRF

Question 14

Serum immunoglobulin screen detects what?

Answer 14

Myeloma

• can do a protein electrophoresis and serum free light chain measurement

Question 15

What blood tests

Answer 15

• U + E
• FBC
• CRP
• PTH
• Iron
• LFTs - albumin
• ANCA - ANCA vasculitis

Question 16

Imaging

Answer 16

MRI - mass
CT - stone or mass
MR angiogram - renal stenosis
USS - hydronephrosis and kidney size

Question 17

Prevention of CKD

Answer 17

Lifestyle modification:

• Stop smoking
• Lose weight
• Exercise
• Control diabetes

Question 18

Treatment of CKD

Answer 18

Anti- hypertensives - ACE inhibitors and Ang II receptor blockers

Diuretics - ferusomide

Fluid restriction

Question 19

CKD GFR

Answer 19

Decreases GFR so can only excrete 1- 2 L of urine a day

Risk of overloading so must restrict fluid intake

Question 20

CKD nocturia

Answer 20

Decreased counter current multiplication therefore smaller concentration gradient

• Smaller glomerular filtrate (less water filtered) but same solute
• Decreased ADH response (normally active at night) therefore get nocturia as less water absorbed by aquaporins in the DCT

Question 21

Hyperkalaemia

Answer 21

Lower eGFR - less K+ excreted

• Stop ACE inhibitors and Ang II receptor blockers as hyperkalemia causes supra ventricular tachycardia
• Avoid K+ sparring drugs e.g. spironolactone
• Altered diet to avoid foods with less K+ e.g. spinach

Question 22

CKD acidosis

Answer 22

Less HCO3- produced

Treat with oral NaHCO3 - flatulence

Question 23

Causes of anaemia in CKD

Answer 23

Vit B12 deficiency

CKD mineral and bone disorder

Bone suppression by hyperuraemia

Absolute iron deficiency - high hepcidin due to:

• reduced hepicidin clearance
• inflammation

Decreased EPO production

Question 24

Hepcidin

Answer 24

Inhibits functional iron release from iron stores

Question 25

Treatment of anaemia

Answer 25

Check iron stores first to check functional iron - If low, give IV or oral iron - Re-check Hb when iron is okay - If still low, give synthetic EPO or erythpoietin starting agent

Question 26

Mineral bone disease

Answer 26

1. Kidney secretes phosphate less and less activated vit D 2. Build up of phosphate in blood and less calcium absorbed from the gut 3. Stimulates PTH 4. Increased bone resorption and increased osteoclastic activity 5. Mineral bone disease

Question 27

Treatment of mineral bone disease

Answer 27

Phosphate binders Low phosphate diet Vitamin D

Question 28

CKD and drugs

Answer 28

Impaired kidney function therefore reduced elimination of drugs. More side effects e.g. rhabdomyolysis with statins Alter dose

Question 29

Effects of accumulation of waste products

Answer 29

Nausea and vomiting Reduced appetite and weight loss Puritis Malaise

Question 30

When is dialysis required?

Answer 30

GFR = 8-10ml/min

Question 31

Symptoms of ESRD dialysis

Answer 31

Difficulty sleeping Malaise Fatigue Difficulty concentrating

Question 32

Types of dialysis

Answer 32

Haemodialysis | Peritoneal dialysis

Question 33

Advantages and disadvantages to haemodialysis

Answer 33

Advantages: - Less responsibility - Days off Disadvantages: - Time travelling to hospital - Tied to dialysis times - Restricted fluid and food intake

Question 34

Advantages and disadvantages to peritoneal dialysis

Answer 34

Advantages: - Can do at home - independence - More bespoke to times patient wants - Better large molecule clearance - Patients feel better and require fewer medications and diet restrictions - Easy to travel Disadvantages: - Require someone at home with them - Frequent daily exchanges - More responsibility - Decreased compliance - Increased risk of peritonitis

Question 35

What can CKD cause

Answer 35

- hyperuricaemia - less urea cleared - Anaemia - Hypertension - Mineral bone disease - Hyperkaleamia - Metabolic acidosis - Dilutional hyponaturaemia

Question 36

Why do patients get hypertension

Answer 36

1. Impaired kidney therefore decreases filtrate as decreased eGFR. 2. Macula densa cells detect low Na+ in DCT indicating low BP 3. Stimulated renin release from JGAin cortical nephrons 4. Stimulates RAAS causing hypertension

Question 37

How to treat hyperkalaemia

Answer 37

Dextrose and insulin Low K+ diet Calcium gluconate

Question 38

Pontine demyelination

Answer 38

If dilutional hyponaturaemia treated too fast