Urinary20 - Chronic Kidney Disease

Question 1

Chronic Kidney Disease

Definition
Staging
Clinical Features
Investigations

Answer 1

1. ) Definition - irreversible and progressive kidney damage causing ↓GFR or albuminuria for > 3months
   - loss of excretory and hormonal kidney functions
2. ) Staging - uses eGFR and albuminuria
   - 1 = >90, 2 = >60, 3a = >45, 3b = >30, 4 = >15
   - Stage 5 is end stage kidney disease (ESRD) and is chacterised by a eGFR of <15
3. ) Clinical Features
   - anaemia: fatigue, SOB, light-headedness etc..
   - ↓GFR: oliguria (max output 1-2L), over-drinking leads to oedema (bilateral pitting leg swelling)
   - ADH insensitivity at night: nocturia
   - accumulation of waste products: N/V, ↓appetite, pruritus, insomina, seizures, difficulty concentrating
   - ↑infecton, ↓libido and ↓fertility
4. ) Investigations
   - bloods: FBC, CRP, U+Es, LFTs, HbA1c
   - albumin, bone profile, lipid profile, iron studies
   - investigate causes of AKI and glomerulonephritis
   - USS abdo (ADPKD), angiogram (stenosis)

Question 2

Causes of Chronic Kidney Disease

Diabetic Nephropathy
Hypertensive Nephropathy
Autosomal Dominant Polycystic Kidney Disease
Others

Answer 2

1. ) Diabetic Nephropathy - most common cause in UK
   - poorly controlled diabetes, T1 or long-duration T2
   - raised urine ACR/PCR
   - treatment: ACEi/ARBs, control diabetes, control HTN, CVD risk modification, screen for other complications4
2. ) Hypertensive Nephropathy - chronic raised BP
   - difficult to tell which came first, the CKD or the HTN
   - investigate potential secondary causes of HTN:
   - hyperthyroidism, Cushing’s syndrome, renal artery stenosis, primary aldosteronism, pheochromocytoma
3. ) ADPKD - mutation in PKD1/2 gene
   - strong FH, presents in adulthood (cysts grow w/ age)
   - sx: infection (flank pain, haematuria, fever), bleeding into cysts, can also be asymptomatic
   - diagnosed w/ USS and FH, control BP, tolvaptan can be used to slow progression of CKD
   - offer genetic counselling/testing
4. ) Others
   - glomerulonephritis, renovascular disease (stenosis)
   - chronic/recurrent pyelonephritis, hydronephrosis
   - prolonged AKI

Question 3

Complications of Chronic Kidney Disease (+management)

Anaemia of Chronic Kidney Disease
Mineral Bone Disease
Cardiovascular Disease
Hypertension
Malnutrition
End-Stage Renal Disease

Answer 3

1. ) Anaemia of Chronic Kidney Disease
2. ) Mineral Bone Disease
3. ) Cardiovascular Disease - No. 1 cause of mortality
   - CKD –> HTN, hyperlipidaemia
   - ↓CVD risk: weight loss, exercise, stops smoking, control BP and diabetes, start on a statin
4. ) Hypertension - kidney can’t regulate blood volume
   - ↑RAAS –> vasoconstriction and Na+ retention
   - SNS overactivity –> vasoconstriction +Na+ retention
   - Na+ retention –> arterial stiffness –> ↑BP
5. ) Malnutrition - multifactorial
   - ↓intake, acidosis, dialysis, ↓absorption (gut oedema)
6. ) End-Stage RD - similar to AKI complications
   - fluid overload: Na+ retention
   - electrolyte disturbance: esp ↑K+ (↓excretion), patients should have a low potassium diet
   - metabolic acidosis: ↓secretion of HCO3-
   - uraemia: encephalopathy and pericaridits

Question 4

Anaemia and Mineral Bone Disease in CKD

Anaemia of Chronic Kidney Disease
Management of Anaemia of CKD
Mineral Bone Disease
Management of MBD

2 ways renal failure causes bone disease

Answer 4

1. ) Anaemia of CKD - many causes
   - ↓EPO production –> normocytic anaemia
   - iron deficiency due to ↓clearance of hepcidin
   - vitB12/folate deficiency
   - bone marrow suppression from uraemia
2. ) Management of Anaemia of CKD - Hb (100-120)
   - PO injections (SC)
   - haematinics: IV iron/vitB12/folate replacement
   - , ferrous sulphate
3. ) Mineral Bone Disease
   - ↓phosphate excretion –> ↑PTH –> ↑bone resorption
   - ↓calcitriol –> ↓serum Ca2+ –> ↑PTH
   - ↑PO4- –> vascular and or soft tissue calcification
   - bone profile: ↓Ca2+, ↑PO4-, ↑PTH, ↑ALP, ↓vitD
   - secondary hyperparathyroidism: parathyroid gland nodular hyperplasia a consequence of advanced CKD
4. ) Management of MBD
   - phosphate: low phosphate diet, phosphate binders
   - secondary hyperparathyroidism: calcimimetics calcitriol, synthetic vitD analogues
   - vitamin D supplements (cholecalciferol)
5. ) Decreased Phosphate Excretion - leads to increase in [PO4] so parathyroid glands secrete PTH
   - PTH increases osteoclasts –> bone resorption

2.) Decreased Formation of Calcitriol
- less conversion of 25-dihydroxyvitaminD3 into
1-25-dihydroxyvitaminD3 (calcitriol)
- leads to less Ca2+ absorption in the SI so fall in plasma Ca2+ which stimulates parathyroid glands to make PTH

Question 5

6 groups of symptoms of chronic kidney disease

Answer 5

1.) Tiredness and SOB - due to anaemia

2. ) Oliguria and Oedema - due to reduced GFR
   - maximum urine output may be 1-2L (usually 30L)
   - therefore, over-drinking leads to oedema
3. ) Nocturia - insensitive to ADH at night time
   - therefore you get less water retention
4. ) Accumulation of Waste Products - mainly uraemia
   - nausea/vomiting, reduced appetite, pruritus,
   - insomina, seizures, difficulty concentrating,
5. ) Increased Infections - antibodies lost in urine
   - reduced cellular and humeral immunity

6.) Reduced Fertility and Sexual Dysfunction

Question 6

4 investigations carried out in CKD

Blood Tests
Screening
Imaging
Biopsy

Answer 6

1. ) General Blood Tests - FBC, U/Es, LFTs, CRP
   - iron levels, PTH, albumin
2. ) Screening - for auto-antibodies or immunoglobulins
   - e.g. ANCA, myeloma
3. ) Imaging - USS most common (kidney size)
   - other: CT, MRI, angiogram (stenosis)

4.) Kidney Biopsy - looking for haematuria or proteinuria

Question 7

Renal Replacement Therapy (Dialysis)

Haemodialysis (HD)
Pros and Cons of HD
Peritoneal Dialysis (PD)
Pros and Cons of PD

Answer 7

1. ) Haemodialysis
   - pumps blood through dialyser (artificial kidney) which removes waste solutes, salt and excess fluid
   - requires AV fistula or central line (permcath)
   - 4-hour dialysis sessions x3 a week
   - can be used temporarily for AKI (vascath)
2. ) Pros and Cons of HD
   - pros: most efficient, help and support, longer-term
   - cons: fluid and diet restrictions, cannot travel, ↑CVD strain, expensive,
   - complications: bacteraemia, hematomas, muscle cramps, haemolysis
3. ) Peritoneal Dialysis - home-based therapy
   - uses patient’s own peritoneal membrane to filter
   - solutes move down the conc gradient across the peritoneal membrane into the dialysate fluid
   - water is removed due to osmotic gradient created by high conc of glucose in the dialysate fluid
4. ) Pros and Cons of PD
   - pros: ↑QoL, fewer diet restrictions, empowers patients, often a good first choice for new patients
   - cons: need to be competent, short-term (eventually need HD), more complications
   - complications: peritonitis, leaks, herniae, drainage problems, hydrothorax, peritoneal sclerosis

Question 8

Kidney Transplantation

General Details
Pros and Cons
Contraindications
Treatment

Answer 8

1. ) General Details
   - treatment of choice for most patients w/ ESRF
   - can be live/dead related/un-related
   - best outcomes in terms of survival and QoL
   - can be simultaneous w/ pancreas (type 1 DM) or liver (cirrhosis) transplants
2. ) Pros and Cons
   - pros: best survival and QoL, near normal renal function, cheap
   - cons: criteria, lifelong immunosuppression, rejection, can be long waiting times, don’t last forever
3. ) Contraindications
   - active infection or malignancy
   - severe heart or lung disease, short life expectancy
   - substance abuse, psychiatric illness, non-adherence
4. ) Treatment - w/ immunosuppresants
   - used at induction and for maintenance
   - corticosteroids, DMARDs