Nephro

Question 1

Acute kidney injury vs. chronic kidney disease

Answer 1

USS
- CKD have bilateral small kidneys except:
ADPKD
diabetic nephropathy (early stages)
amyloidosis
HIV-associated nephropathy

• CKD rather than AKI= hypocalcaemia (due to lack of vitamin D)

Question 2

AKI dx & ix

Answer 2

urine output of less than 0.5 ml/kg/hour for more than 6 hours

rise in serum creatinine of 26 micromol/litre or greater within 48 hours

50% or greater rise in serum creatinine within the past 7 days

All pts
- urinalysis
- renal ultrasound within 24 hours of assessment if no identifiable cause / risk of obstruction

Question 3

AKI stage

Answer 3

1
Increase in creatinine: 1.5-1.9x or ≥26.5µmol/L
Reduction in urine output to <0.5 mL/kg/hour for ≥ 6 hours

2
Increase in creatinine: 2-2.9x
Reduction in urine output to <0.5 mL/kg/hour for ≥ 12 hours

3
Increase in creatinine: >3x or ≥353.6 µmol/L
Reduction in urine output to <0.3 mL/kg/hour for ≥24 hours
Initiation of kidney replacement therapy

Question 4

eGFR CKD classification

Answer 4

(uses serum creatinine, age, gender, ethnicity)

(Factors affecting result- preganacy, muscle mass, eating red meat 12hrs prior)

Stage 1 - >90ml/min
2 - 60-90
3a - 45-59
3b - 30-44
4 - 15-29
5- <15

(stage 1& 2 need other tests to show abnormal kidney function, otherwise no ckd)

Question 5

Chronic kidney disease: mineral bone disease management

Answer 5

aim is to reduce phosphate and parathyroid hormone levels.

first line: reduced dietary intake of phosphate

phosphate binders (sevelamer, etc)

vitamin D: alfacalcidol, calcitriol

parathyroidectomy may be needed in some cases

Question 6

Diabetes insipidus (DI) mx

Answer 6

nephrogenic diabetes insipidus
thiazides
low salt/protein diet

central diabetes insipidus can be treated with desmopressin

Question 7

SIADH mx

Answer 7

Management
correction must be done slowly to avoid precipitating central pontine myelinolysis
fluid restriction
demeclocycline: reduces the responsiveness of the collecting tubule cells to ADH
ADH (vasopressin) receptor antagonists have been developed

Question 8

Focal segmental glomerulosclerosis Ix & mx

Answer 8

(HIV, sick cell, other renal pathology)

Investigations
renal biopsy
focal and segmental sclerosis and hyalinosis on light microscopy
effacement of foot processes on electron microscopy

Management
steroids +/- immunosuppressants

Question 9

Referral criteria for haematuria 2ww

Answer 9

Aged >= 45 years AND:
unexplained visible haematuria without urinary tract infection, or
visible haematuria that persists or recurs after successful treatment of urinary tract infection

Aged >= 60 years AND have unexplained nonvisible haematuria and either dysuria or a raised white cell count on a blood test