Assessment of Renal Function 2 + CKD

Question 1

Stages of AKI

Answer 1

Stage 1 = >26 increase in creatining or by 1.5-1.9x the reference

Stage 2 = increase by 2.0-2.9x the reference

Stage 3 = increase by >3x the reference or up by >354

Question 2

Classification of causes of AKI

Answer 2

Pre-renal
Renal
Post-renal

Question 3

Pathophysiology of pre-renal AKI

Answer 3

Reduced renal perfusion
Can be generalised or selective
Generalised = shock
Selective = normal response to reduced circulating volume

Question 4

Causes of pre-renal AKI

Answer 4

True volume depletion - haemorrhage
Hypotension
Oedematous state
Selective renal ischaemia
Drugs affecting renal blood flow - ACEi, NSAIDs, calcineural inhibitors, diuretics

Question 5

What is acute tubular necrosis?

Answer 5

Ischaemic injury to renal cells after prolonged hypoxia

Question 6

What is seen in urine in ATN?

Answer 6

Epithelial cell casts

Question 7

What is the main cause of post-renal AKI?

Answer 7

Obstruction of urine flow

Can be at numerous sites = intrarenal, ureteric, prostatic/urethral, blocked catheter

Question 8

What are the main causes of renal AKI?

Answer 8

Direct tubular injury: 
Ischaemic damage (ATN)
Toxins - endogenous (myoglobin, immunoglobulins) and exogenous (aminoglycosides, amphotericin, aciclovir)

Immune dysfunction:
Glomerulonephritis
Vasculitis

Infiltration/abnormal protein deposition:
Amyloidosis
Lymphoma
Myeloma

Question 9

Stages of CKD

Answer 9

1 - kidney damage with normal GFR (>90)
2 - mild decrease in GFR (60-89)
3- moderate decrease in GFR (30-59)
4 - severe decrease in GFR (15-29)
5 - end stage kidney failure (<15 or dialysis)

Question 10

Common causes of CKD

Answer 10

DM
Atherosclerosis of renal vessels
HTN
Chronic GN
Infective or obstructive uropathy
PCKD

Question 11

What is the acid base abnormality associated with CKD?

Answer 11

Metabolic acidosis

Question 12

What is a common consequence of CKD, especially among diabetics?

Answer 12

Hyperkalaemia

Question 13

What type of anaemia occurs in CKD?

Answer 13

Normochromic, normocytic

Question 14

What happens to phosphate/PTH/vitamin D/calcium in CKD?

Answer 14

Retained phosphate causes rise in PTH
Bone becomes resistant to PTH - hypocalcaemia
Vitamin D cannot be activated

Question 15

Management of renal bone disease

Answer 15

Bring down phosphate - dietary, phosphate binders
Vitamin D receptor activators
Direct PTH suppression