Pre-Renal AKI (e.g., Dehydration, Heart Failure)

Pre-renal acute kidney injury (AKI) is marked by diminished kidney function due to reduced blood flow (renal hypoperfusion) to the kidneys, without any intrinsic structural damage. Dehydration, significant fluid loss (from vomiting, diarrhoea, or bleeding), and heart failure are all prominent causes of hypoperfusion. In dehydration, a decrease in circulation volume results in decreased renal perfusion pressure and a lowered glomerular filtration rate (GFR).

Heart failure can also cause pre-renal AKI by lowering cardiac output and raising central venous pressure, which means that the kidneys don't receive enough blood. When blood flow is low, the kidneys take back salt and water to keep blood volume and pressure up. If the underlying issue, such as low blood volume or heart failure, is treated quickly, the kidneys usually work again. But if hypoperfusion lasts too long, it might cause ischaemic injury and eventually lead to intrinsic renal impairment.

Patients with pre-renal acute kidney injury (AKI) may exhibit diminished urine production, indicators of dehydration (including dry mucous membranes, decreased skin turgor, or hypotension), or manifestations of fluid overload in the context of heart failure (such as oedema or dyspnoea). To stop progression, it is important to quickly identify, restore volume, and treat the underlying heart problem.