Oliguria & Renal Failure

Question 1

Most common cause of acute renal failure in the ICU

Answer 1

Sepsis

Question 2

Features of acute renal failure

Answer 2

Reduction in glomerular filturation rate by 75%

Threefold increase in creatinine

Creatinine >350

Acute rise in creatinine

Anuria for more than 12 hours

Urine output <0.3mL/kg/h for 24 hours

Question 3

How sensitive are urea nad creatinine as markers for glomerular filtration rate?

Answer 3

Insensitive.

Only beocme abnormal when there has been a >50% drop.

Question 4

Other than renal failure, what can affect urea and creatinine levels?

Answer 4

Nutrition, muslce injury, steroids, GI bleeding.

Question 5

What investigations should be run in suspected renal failure?

Answer 5

U&Es

Creatine kinase

ABG

Urine dipstick

Question 6

Aim for what MAP when managing renal failure?

Answer 6

> 70-75

Question 7

How do you treat severe hyperkalaemia? Drugs and doses.

Answer 7

1. Calcium gluconate 10% 10mL by slow IV injection (repeat in 5 minutes if no improvement on ECG)
2. 10U insulin IV bolus
3. 50mL 50% glucose IV bolus

+/- inhaled B2 agonist.

Monitor blood glucose concentration carefully.

4. Renal replacement therapy

Question 8

Indications for urgent renal replacement therapy:

Answer 8

Severe hyperkalaemia

Metabolic acidosis

Pulmonary oedema

Uraemic pericarditis

Question 9

Treatment for rhabdomyolysis

Answer 9

Aggressive fluid resuscitation

Maintenance of polyuria (>100mL/hr)

Treat the cause:
- Fasciotomy (muscle compartment syndrome)
- Anti-epileptic drugs (status epilepticus)
- Cooling (heatstroke)
- Dantrolene (malignant hyperthermia)
- Antivenom (snakebite)