The Kidney Clinic

Acute Kidney Injury (AKI)

Acute kidney injury (AKI), which is also referred to as acute renal failure (ARF), is when your kidneys suddenly stop working properly. It can range from a minor loss to a complete loss of kidney function. In acute kidney injury, the kidneys are not able to effectively remove waste products from your blood and have difficulty maintaining the right balance of salt, acidity and fluid in your body. This will affect the normal functioning of other organs, such as the brain, heart, and lungs.

Chronic kidney disease is different from acute kidney injury, in which there is a gradual loss of kidney function over a long period of time, and the causes might not be as noticeable.

Causes of Acute Kidney Injury

There are three major types of acute kidney injury, all of which have different causes. These are postrenal acute kidney injury, which is situated below the kidneys; intrinsic acute kidney injury, which is inside the kidneys; and prerenal AKI, which is above the kidneys. The causes of these types of acute kidney injury include:


Causes of Postrenal Acute Kidney Injury:

  •  Prostate cancer
  •  Enlarged prostate
  •  Neurogenic bladder
  •  Bladder or kidney stones
  •  Bladder cancer


Causes of Intrinsic Acute Kidney Injury:

  •  Severe kidney infections
  •  Toxic medications affecting the kidneys, such as anti-inflammatory drugs, antibiotics, or proton pump inhibitors
  •  Tumour lysis syndrome
  •  Traumatic injuries such as blunt-force trauma and crush injuries


Causes of Prerenal acute kidney injury:

  •  Sepsis
  •  Liver failure
  •  Heart failure
  •  Heart attack
  •  Hypovolemia
  •  Renal artery thrombosis


Symptoms of Acute Kidney Injury 

Due to the instantaneous nature of acute kidney injury, a person may develop multiple acute kidney injury symptoms rapidly. The symptoms they experience can include a lack of urine or no urine flow, swelling in legs, ankles and around the eyes, fatigue, tiredness, breathlessness, confusion, nausea, seizures or even coma in severe cases. 

In some cases, acute kidney injury can occur without any apparent symptoms and is detected only while a person is hospitalised or being treated for a different condition.

Risk Factors of Acute Kidney Injury

    • The elderly,
    • Those who suffer from pre-existing kidney problems,
    • Those who have a long-term disease such as heart failure, liver failure or diabetes,
    • Those who have severe infection or sepsis (blood poisoning),
    • Those who have a urinary blockage,
    • And those taking certain medications, especially in excess or were unwell when taking regular doses of the medication.

Treatment Options

If left untreated, acute kidney injury can develop into many other complications, all of which may be fatal. For example, the rapid build-up of toxins can cause pulmonary oedema or hyperkalemia, which can then lead to heart rhythm problems or respiratory failure.

The most standard treatment of acute kidney injury involves finding its cause. It is the most appropriate acute kidney injury treatment because addressing the origin directly allows its immediate elimination, leading to recovery. However, if a person has severe acute kidney injury, he or she may require temporary dialysis support until their kidneys fully recover. 

Unfortunately, even after treatment, there may still be a risk of retaining permanent damage, which can then lead to chronic kidney disease. Therefore, it is imperative to detect acute kidney injury early and get treated promptly.

Do you have a question about your kidney or medical condition?

Reach out to us for a consultation with Dr Alvin Ng. 

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