Question

RIFLE defines three stages of AKI based on changes in:

1) blood pressure and urine osmolality
2) fractional excretion of urinary sodium
3) estimation of GFR with the MDRD equation
4) serum creatinine or urine output from baseline

Answer 1

The RIFLE criteria for acute kidney injury are based on changes in serum creatinine and urine output from baseline, focusing on three stages: Risk, Injury, and Failure. The correct option is (4).

Step-by-step explanation:

RIFLE defines three stages of Acute Kidney Injury (AKI) based on specific changes in kidney function. These stages are determined by changes in serum creatinine or urine output from baseline. The stages are:

• Risk: serum creatinine increased 1.5 times OR urine production of <0.5 ml/kg body weight for 6 hours.
• Injury: serum creatinine 2.0 times OR urine production <0.5 ml/kg for 12 hours.
• Failure: serum creatinine 3.0 times OR serum creatinine >355 mmol/l (with a rise of >44) or urine output below 0.3 ml/kg for 24 hours.

These stages do not include changes in blood pressure, urine osmolality, fractional excretion of urinary sodium, or estimation of GFR with the MDRD equation; rather, they focus on the loss of kidney function and output.

Diagnosis of AKI often involves comparing current renal function to previous levels, whether through creatinine, blood urea nitrogen levels, or other tests like GFR determination and renal ultrasonography.