Acute Kidney Injury

Acute kidney injury (AKI) is a sudden loss of kidney function, ranging from a few hours to several days. Patients may be asymptomatic or produce little to no urine; in severe cases, they may exhibit symptoms affecting various organ systems.

AKI may be diagnosed based on blood work, as it is marked by increased creatinine levels. To prevent irreversible kidney damage, AKI must be diagnosed and treated early. Treatment of AKI aims to ensure that the kidneys can filter the blood adequately and prevent further kidney damage and complications.

Stages of Acute Kidney Injury

The stages of Acute Kidney Injury are as follows:

Stage 1

Initiating phase: Injuries to the kidneys occur.

Stage 2

Oliguric/anuric phase: Kidney function deteriorates, causing a decrease in urine output (oliguria) or a lack thereof (anuria).

Stage 3

Polyuric/Diuretic phase: Urine output increases in this phase (polyuria) as the glomerular filtration rate reaches normal levels. However, the body loses electrolytes and water as a result, and tubule scarring, and injury may also be present.

Stage 4

Recovery phase: Kidney function and urine production reach normal levels.

Frequently Asked Questions

What is the difference between kidney failure and acute kidney injury?

The terms “acute kidney injury (AKI)” and “acute renal failure (ARF)” are used interchangeably.

AKI is a serious condition that must be treated immediately to avoid permanent kidney damage.

AKI may result in cardiovascular and musculoskeletal issues. In severe cases, elevated potassium levels due to AKI may also result in paralysis and muscle weakness. Furthermore, AKI causes fluid buildup in the lungs and acidic blood pH, resulting in nausea, vomiting, and drowsiness.

AKI can be diagnosed by measuring creatinine levels via a blood test. The kidney is the only organ capable of removing creatinine. Therefore, creatinine levels are elevated when the kidneys are not functioning sufficiently.

There are three root causes behind AKI:

  • Insufficient blood flow to the kidneys
  • Blockage in urine flow resulting in infections
  • Direct kidney damage (e.g., via infections, medications, or autoimmune conditions)

If the patient experiences persistent diuresis at a rate of 250 mL/hr. or more for two hours after prolonged obstruction, they should be admitted.

Yes, acute kidney failure can be reversed if medical attention is sought immediately. Patients with stable recovery may fully regain kidney function.

The median recovery time is 2 months, with 95% recovering within 12 months.

In addition to preserving and optimizing renal function, AKI treatments correct and maintain electrolyte, acid-base, and mineral homeostasis. They can also manage the consequences of renal impairment and prevent secondary organ damage.