Acute Kidney Injury

Acute kidney injury (AKI) is a sudden reduction in kidney function occurring over hours to days. To see why it is dangerous, start with what the kidneys do continuously: they filter the blood, excrete potassium and acid, regulate salt and water, and clear creatinine, urea and many medications. When filtration falls, every one of those jobs slows at once, so AKI is rarely one problem. It is a fall in glomerular filtration that allows several problems to develop together. AKI may cause: - reduced glomerular filtration; - accumulation of creatinine and urea; - fluid and electrolyte disturbances; - metabolic acidosis; - impaired medication clearance; - uraemic complications; - increased morbidity and mortality. The practical consequence for the nurse is that the creatinine number is not the emergency. The emergency is what the failing kidney allows to happen: potassium that disturbs cardiac conduction, fluid that fills the lungs, acid that depresses the circulation, and medications that accumulate to toxic levels. ### How AKI is defined The KDIGO guideline defines AKI by any one of the following: | Criterion | Threshold |...