Renal - L2 CKD

Question 1

CKD - 3

Answer 1

1. All individuals with markers of kidney damage
2. Or eGFR of <60 ml/min/1.73m2 on at least 2 occasions 90 days apart (with or without markers of kidney damage).
3. Can progress to CKD 5 (GFR <15ml/min)

Question 2

Causes of CKD – 8

Answer 2

1. Generally chronic conditions, (so kidney gets worse over time)
2. Diabetes
3. Hypertension
4. Glomerulonephritis
5. Polycystic kidney disease (most common)
6. Current or previous AKI (acute kidney injuries)
7. Pyelonephritis
8. Nephrotoxic Drugs e.g. gentamicin

Question 3

Measurements needed to classify CKD - 2

Answer 3

1. G1- G5. G1 is >90, G5 is <15 – kidney failure
2. ACR (albumin creatinine ration) – how much protein is in urine. > 30 lots of protein in urine – filters not working well

Question 4

Usual role of the kidneys – 6

Answer 4

1. Regulate electrolyte & water homeostasis
2. Remove waste product via urine
3. Regulate BP
4. Create EPO (erythropoietin) to produce RBCs
5. Activate vit D for bone health
6. Many drugs excreted to some extent via kidneys

Question 5

Complications of CKD - 6

Answer 5

1. Fluid overload
2. Electrolyte imbalance e.g. can become acidotic
3. Hypertension (due to increase in fluid)
4. Mineral bone disease
5. Renal anaemia
6. Altered drug handling

Question 6

Symptoms of renal disease – 10

Answer 6

1. Fatigue
2. Shortness of breath
3. Weight loss & poor appetite
4. Nausea
5. Headaches
6. Leg, ankle & Hand swelling (fluid overload)
7. Muscle cramps
8. Itching (high urea levels)
9. Drowsiness
10. Poor sleep

Question 7

CKD-Mineral Bone Disease – 6

Answer 7

1. CKD decreases GFR, less phosphate excreted & less vitamin D activated
2. Reduced GFR results in increased serum phosphate, which binds to calcium, reducing free calcium levels.
3. Less activated vitamin D reduces calcium absorption from gut
4. Body senses low calcium & high phosphate, stimulates parathyroid glands to release more PTH
5. PTH breaks down osteoclast activity, releasing calcium & phosphate, increasing calcium reabsorption in kidneys, stimulating active vitamin D
6. High PTH causes increased bone turnover, causing bone loss & weakness due to bone leeching

Question 8

Renal anaemia: Variety of causes – 5

Answer 8

1. Decreased EPO production
2. Downregulated hypoxia-inducible factor (HIF)
3. Deformity in red blood cells due to uraemia
4. Iron, folate, B12 deficiency
5. Loss of blood on haemodialysis

Question 9

Treatment of renal anaemia - 2

Answer 9

1. NICE guidance recommends investigation & treatment once Hb falls to <110g/L or patient becomes symptomatic w/ anaemia
2. Identify & correct treatable causes i.e. low iron stores, B12 or folate deficiencies, erythropoiesis-stimulating agents (ESAs): EPO e.g. darbepoetin

Question 10

Pharmacokinetics - 4

Answer 10

1. Absorption: Gut oedema & decreased motility
2. Distribution: Changes to protein binding in hypalbuminaemia &/or uraemia can be significant e.g. phenytoin, benzodiazepines.
3. Metabolism: Few drugs metabolised by the kidneys e.g. insulin, vitamin D.
4. Excretion: Drugs & metabolites excreted by the kidneys will have reduced clearance = increased half-life.

Question 11

Excretion – 4

Answer 11

1. Drugs excreted unchanged in urine - Clinically significant for drugs which are excreted > 25% unchanged in the urine.
2. Producing active may cause unwanted S/Es accumulation
3. Reduced clearance results in prolonged half life
4. Some drugs must be excreted into urine for pharmacological action e.g. nitrofurantoin, pivmecillinam

Question 12

Renal replacement therapy: Haemodialysis - 4

Answer 12

1. Patient connected to machine for up to 4hrs 3 days a week
2. A tube can be placed to connect an artery & vein for dialysis
3. Emergency dialysis – tube may be placed in chest
4. Bicarbonate may be put in to stop patient becoming acidotic

Question 13

Renal replacement therapy: Peritoneal dialysis - 4

Answer 13

1. Patients have a tube in abdomen, fluid enters
2. Peritoneal membrane acts as filter within the abdomen
3. Machine can perform this over night
4. Peritoneal abdomen will eventually thicken, so a kidney replacement of Haemodialysis become necessary

Question 14

CKD Management outline – 10

Answer 14

1. Patient is identified as having CKD
2. Cardiovascular risk factors optimized – reduce weight, salt, alcohol, smoking, exercise
3. Use ACEi or ARB, titrate to max dose
4. Prescribe a statin (e.g. atorvastatin 20)
5. Get Hba1c at appropriately level
6. Drugs may push up K, so K binders may be used
7. For Type 1 Diabetes, no more can safely be done
8. For without diabetes or Type 2 Diabetes, addition of SGLT2i given
9. If eGFR 25-59 and Type 2 Diabetes, may give Finereone additionally
10. Dose dependant on Serum potassium