Medicine (11) Flashcards
Causes of CKD (mnemonic)
‘HIDDEN’
- Hypertension
- Infection (ureteric reflux in childhood)
- Diabetes
- Drugs (analgesic nephropathy)
- Exotica (SLE/vasculitis)
- Nephritis (glomerulonephritis)
How CKD affects different systems across the body?
- Nervous → peripheral neuropathy, encephalopathy, fatigue
- Cardiovascular → accelerated atherogenesis, fluid overload, pericarditis
- Gastrointestinal → impaired taste
- Musculoskeletal → renal osteodystrophy, gout
- Blood → anaemia (reduced EPO secretion)
- Respiratory → pulmonary oedema
- Skin → pruritus (phosphate retention)
Symptoms of CKD (2x mnemonics)
(5) results of CKD
- Uraemia
- ↑K+, ↑PO4-
- Fluid overload/Hypertension
- Metabolic acidosis
- Anaemia (EPO)
- Secondary hyperparathyroidism, ↓Ca2+
Uremic syndrome in CKD
- pathophysiology
- at what stage of CKD does it occur?
- symptoms
Failure to excrete metabolic waste → results in “uraemic” syndrome
- Occurs late (eGFR <15ml/min)
- Symptoms → nausea, anorexia, lethargy, restless legs, itchy
- Late symptoms → pericarditis, encephalopathy, neuropathy
Hyperkalaemia/hyperphosphatemia in CKD
- pathophysiology
- symptoms
Failure to regulate fluid/electrolytes → results in:
- Hyperkalaemia
- Hyperphosphataemia
Symptoms:
- Nocturia (loss of physiological nocturia anti-diuresis)
- Polyuria and thirst (due to loss of urine concentrating ability
How does CKD lead to fluid overload/hypertension?
Failure to regulate fluid balance → leads to:
- Acute renal failure → patients may become oliguric → results in fluid overload unless fluid input is reduced
- Increase in blood pressure due to activation of the Renin-Angiotensin- Aldosterone system
How does CKD lead to metabolic acidosis?
Failure of acid-base homeostasis
Decreased H+ excretion results in:
- Metabolic acidosis
- Low bicarbonate
Why does CKD may lead to anaemia?
Failure of erythropoietin (EPO) production → Normochromic anaemia of renal failure
How does CKD result in hyperparathyroidism?
CKD → Failure of vitamin D hydroxylation
Active vitamin D needs:
- 25-hydroxylation in the liver, 1-hydroxylation in the kidney
- reduced activation → reduced calcium → PTH activation
Deficiency results in:
- Hypocalcaemia
- Osteomalacia
- Secondary hyperparathyroidism
- Renal osteodystrophy
Renal osteodystrophy
- pathophysiology
- Phosphate excretion is insufficient → plasma phosphate rises → stimulating PTH
- 1-alpha-hydroxylation of vitamin D is impaired which depresses PTH and reduces calcium absorption and serum calcium, further stimulating PTH
- Rise in PTH causes activation of osteoclasts and osteoblasts → leads to disorganised bone activity → bone loss/fractures → back pain/vertebral crush fractures
Management of CKD
Conservative
- Education
- Low potassium diet
- Low phosphate diet (or phosphate
binders)
Medical
- Anaemia (if suitable → EPO stimulators)
- Oral bicarbonate (if GFR <30 and HCO3- <20)
- Cholecalciferol if vitamin D deficiency
- Hypertension management
- Cardiovascular risk → Atorvastatin 20mg
- Aspirin if for secondary prevention
Management of hypertension in patient with CKD
- if non diabetic and ACR <30 → in line with guidelines
- If non-diabetic and ACR >30 → ACEi/ARB
- If diabetic → ACEi/ARB
