Acute Renal Failure

Question 1

What is acute renal failure?

Answer 1

loss of renal function resulting in decreased GFR, fluid-electrolyte imbalances and azotemia

Question 2

Is acute renal failure reversible?

Answer 2

usually, yes

Question 3

What is the minimum amount of urine you need to make per day in order to avoid azotemia?

Answer 3

400 mL/day

Question 4

What does oliguria mean?

Answer 4

100 - 400 mL urine/day

Question 5

What does anuria mean?

Answer 5

under 100 mL urine/day

Question 6

What are the 3 categories of causes of renal failure?

Answer 6

1) pre-renal - hypotension and hypovolemia
2) intra-renal - problem in the kidney
3) post-renal - problem after the kidney, ex. BPH

Question 7

What is the pathology of acute renal failure?

Answer 7

1) pre-renal - ex. dehydration leads to inadequate renal perfusion, decreased GFR, ischemic damage to kidneys and oliguria
2) intra-renal has 3 phases:
i) initiating phase - time of cause to time manifestations appear
ii) maintenance phase - maintenance of problem, decreased GFR and oliguria
iii) recovery phase - gradual, 2 weeks before recovery beings, gradual increase in GFR
3) post-renal - ex. BPH, obstruction of urine flow leads to hydroureter, hydronephrosis

Question 8

What are manifestations of acute renal failure?

Answer 8

• oliguria or anuria (IT IS POSSIBLE to have non-oliguric renal failure)
• fluid and electrolyte imbalances
• azotemia (from retaining nitrogenous waste)
• proteinuria and hematuria

Question 9

What are complications of acute renal failure?

Answer 9

• hypertension (from fluid retention)

- edema (from increased hydrostatic pressure and loss of protein)

Question 10

How is acute renal failure treated?

Answer 10

• STAT intervention
• replace fluids and electrolytes but monitor carefully since we do not know exactly how much we need to give and the kidneys cannot adjust
• dialysis in severe cases
• change the diet (higher calories, low protein)