Chronic renal failure

Question 1

Features of CKD

Answer 1

Kidney damage ≥3mo indicated by ↓ function
Symptoms usually only occur by stage 4 (GFR<30)
ESRF is stage 5 or need for RRT

Question 2

Classification of CKD

Answer 2

1 >90
2 60-89
3 30-59
4 16-29
5 <15

Question 3

Common causes (2)

Answer 3

DM

HTN

Question 4

Other causes

Answer 4

RAS
  GN
  Polycystic disease
  Drugs: e.g. analgesic nephropathy   Pyelonephritis: usually 2O to VUR   SLE
  Myeloma and amyloidosis

Question 5

History of CKD

Answer 5

Past UTI
  HTN, DM
  FH
  DH
  Symptoms

Question 6

Investigations - bloods

Answer 6

↓Hb, U+E, ESR, glucose, ↓Ca/↑PO4, ↑ALP, ↑PTH, ESR
Immune: ANA, dsDNA, ANCA, GBM, C3, C4, Ig, Hep serology
Se protein electrophoresis
Film: burr cells

Question 7

Investigations - urine

Answer 7

DIP - haematuria, proteinuria, glycosuria
PCR - normal <20mg/mM, Nephrotic >300mh/mM
BJP - myeloma

Question 8

Investigations - imaging

Answer 8

CXR: cardiomegaly, pleural/pericardial effusion, oedema
AXR: calcification from stones
Renal US
Usually small (<9cm)
May be large: polycystic, amyloid
Bone X-rays: renal osteodystrophy (pseudofractures)
CT KUB: e.g. cortical scarring from pyelonephritis

Question 9

Investigations - biopsy

Answer 9

If cause unclear and size normal of kidney
Histology subtype
Amyloid: apple-green birefringence with congo red

Question 10

Complications - CRF HEALS

Answer 10

Cardiovascular disease
  Renal osteodystrophy
  Fluid (oedema)
  HTN
  Electrolyte disturbances: K, H
  Anaemia
  Leg restlessness
  Sensory neuropathy

Question 11

Renal osteodystrophy features

Answer 11

Osteoporosis: ↓ bone density
Osteomalacia: ↓ mineralisation of osteoid (matrix)
Sec/Tertiary HPT osteitis fibrosa cystica
Subperiosteal bone resorption
Acral osteolysis: short stubby fingers Pepperpot skull
May get spinal osteosclerosis Rugger Jersey spine Sclerotic vertebral end-plate ̄c lucent centre
Extra skeletal calcification e.g band keratopathy

Question 12

Mechanism of renal osteodystrophy

Answer 12

↓ 1alpha -hydroxylase → ↓ vit D activation → ↓ Ca → ↑ PTH
Phosphate retention → ↓ Ca and ↑ PTH (directly)
↑ PTH → activation of osteoclasts ± osteoblasts
Also acidosis → bone resorption

Question 13

General management

Answer 13

Rx reversible causes
Stop nephrotoxic drugs
NA and K and fluid and phosphate restriction

Question 14

Lifestyle management

Answer 14

Exercise
Healthy wt.
Stop smoking
Na, fluid and PO4 restriction

Question 15

CVS Risk

Answer 15

Statins (irrespective of lipids)
Low-dose aspirin
RxDM

Question 16

Hypertension and oedema treatment

Answer 16

Target <140/90 (<130/80 if DM)
In DM kidney disease give ACEi/ARB (inc. if normal BP)
Frusemide

Question 17

Bone disease treatment

Answer 17

Phosphate binders: sevelamer, calcichew
Vit D analogues: alfacalcidol (1 OH-Vit D3)
Ca supplements
Cinacalcet: Ca mimetic

Question 18

Anaemia treatment

Answer 18

Exclude IDA and ACD

EPO to raise Hb to 11g/dL (higher = thrombosis risk)

Question 19

Restless legs treatment

Answer 19

Clonazepam