PHYS Acute & Chronic Renal Failure - Week 10

Question 1

Renal insufficiency

Answer 1

Renal insufficiency – decline in renal function to about 25% of normal or a GFR of 25-30ml/min (serum urea & creatinine usually mildly elevated).

Question 2

AKI definition

Answer 2

Acute kidney injury (renal failure): acute, rapidly progressing (within 48 hrs), possibly reversible, urine output reduction, need for renal replacement therapy or combination of these factors.

Question 3

Azotemia

Answer 3

Increased serum & creatinine levels.

Question 4

CKI/CKD

Answer 4

Chronic kidney injury/disease (renal failure): chronic, progressing to end-stage failure, period of mths/yrs, secondary to the definitive change in function and/or structure of the kidney.

Question 5

CKD clinical manifestations

Answer 5

GFR < 60ml/min/1.73m2 or GFR > than previous, but with evidence of kidney injury for >3 mths.

Question 6

Pre-renal causes of AKI and examples.

Answer 6

Obstruction of blood flow to the kidneys.
E.g., intrarenal vasoconstriction (medications, hepatorenal syndrome), systemic vasodilation (sepsis, neurogenic shock), volume depletion (renal loss, diuretics, vomiting, diarrhoea, burns, blood loss).

Question 7

Intra-renal causes of AKI and exampes.

Answer 7

Reduced/loss of nephron function.
E.g., glomerular (glomerulonephritis), interstitial (medications, infections, systemic diseases like lupus or sarcoidosis), tubular (ischemia, nephrotoxic substances like contrast media), vascular (renal atheroembolic disease, renal vein thrombosis, malignant hypertension).

Question 8

Post-renal causes of AKI and examples.

Answer 8

Occlusion of outflow tracks.
E.g., extrarenal obstruction (prostate hypertrophy, neurogenic bladder, bladder/cervical/prostate cancer), intrarenal obstruction (stones, crystals, clots, tumours).

Question 9

List risk factors for AKI

Answer 9

• Older age
• Sepsis
• Hypovolemia/shock
• Cardiac surgery
• Infusion of contrast agents
• Diabetes mellitus
• Pre-existing CKD
• Cardiac failure
• Liver failure.

Question 10

What 2 kidney pathologies are seen in all cases of CKD?

Answer 10

Glomerulosclerosis & tubulointerstitial fibrosis.