Acute Kidney Injury

When should AKI be suspected?

A doctor may suspect AKI in people known to be at risk who suddenly fall ill or develop symptoms which suggest complications of AKI.

AKI may also be suspected in people who have been unwell for a while and have either:

• chronic kidney disease
• a urinary system disease
• new or worsening urinary symptoms
• symptoms or signs of a disease affecting the kidneys and other organs

Diagnosing acute kidney injury

AKI can be diagnosed after measuring urine output and doing blood tests.

Blood levels of creatinine a chemical waste product produced by the muscles will be measured. Healthy kidneys filter creatinine and other waste products from the blood and these are excreted, in the form of urine.
It's an easy and quick marker of kidney function, with higher levels of creatinine in the bloodindicating poorer kidney function.

In adults, a diagnosis of AKI can be made if:

• blood creatinine level has risen from the baseline value for that person (by 26 micromoles per litre or more within 48 hours)
• blood creatinine level has risen over time (by 50% or more within the past 7 days)
• they are passing much less urine (less than 0.5ml per kg per hour for more than 6 hours)

In children and teenagers, doctors should use the plasma creatinine level to calculate the estimated glomerular filtration rate ( estimated glomerular filtration rate (eGFR). A diagnosis of AKI is made if they have a 25% or greater fall in eGFR within the past 7 days.

They may:

• advise stopping any medication that may becausing the situation, or making it worse it may be safe to resume some of these when the problem is sorted
• treat any underlying infections
• advise on fluid intake to prevent dehydration (which could cause or worsen AKI)
• take blood tests to monitor levels of creatinine and salt to check how well a person is recovering
• refer to a urologist (genitourinary surgeon) or nephrologist (kidney specialist) if the cause isn't clear or if a more serious cause is suspected

Admission to hospital

Admission to hospital is necessary in cases where:

• there's an underlying cause that needs urgent treatment such as a urinary blockage, or if the person is seriously unwell; most people need hospital care to treat the underlying cause, allowing the AKI to get better
• there's a risk of urinary blockage because of prostate disease, for example:
1. the person's condition has deteriorated , and regular blood and urine tests are needed to monitor how well their kidneys are working
2. the person has a complication of AKI

The majority of people who recover from AKI end up with a very similar level of kidney function as they had before they became ill, or go on to have normal kidney function.

However, some people go on to develop chronic kidney disease or long-term kidney failure as a result. In severe cases, dialysis where a machine filters the blood to rid the body of harmful waste, extra salt and water may be needed.