Acute Kidney Injury ( AKI ) : Triage

Acute Kidney Injury (AKI) is a critical medical condition characterized by a rapid decline in kidney function, which can occur within hours or days. This condition is marked by an increase in serum creatinine levels and/or a decrease in urine output. The term AKI has replaced the older terminology of acute renal failure (ARF) to emphasize the spectrum of kidney injury, ranging from mild impairment to severe failure.

Acute kidney injury (AKI) is a complex condition with multiple potential causes, often occurring simultaneously. Traditionally, these causes are categorized into three groups:

1. Pre-renal causes (most common) – result from reduced blood perfusion to the kidneys, leading to a decrease in glomerular filtration rate (GFR). This form of AKI is typically reversible with prompt treatment. Conditions such as dehydration, heart failure, or hypotension commonly contribute to pre-renal AKI【Makris, 2016; Think Kidneys, 2018b; NICE, 2019】.

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3. Intra-renal (or intrinsic) causes – involve direct structural damage to the kidney, including damage to the tubules, glomeruli, or blood vessels. This form of AKI can occur when pre-renal or post-renal issues persist, leading to irreversible injury to renal cells【Makris, 2016; Think Kidneys, 2018b】.

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5. Post-renal causes (least common, accounting for around 10% of cases) – result from acute...