Acute Kidney Injury: Symptoms, Causes, Diagnosis & Treatment

Acute kidney injury is a condition commonly seen in hospitalized patients. When the kidney suddenly stops working properly, it is called acute kidney injury (AKI). It generally happens within a few hours or a few days and is also known as acute renal failure or acute kidney failure. Besides patients in intensive care units, older adults with health complications are highly likely to develop this condition.

In this condition, dangerous levels of waste products and fluids accumulate in the body. AKI is usually reversible if it is treated quickly. It can affect the function of other vital organs if immediate attention is not given. Read more to know about acute kidney injury symptoms, causes, diagnosis, and treatment. 

What Are Acute Kidney Injury Symptoms?

Depending on the cause, acute kidney injury symptoms can differ, and people may experience:

• No urine output
• Swelling in the ankles, legs, and around the eyes
• Nausea
• Tiredness
• Confusion
• Pain or pressure in the chest
• Shortness of breath
• Drowsiness
• Diarrhea 
• Poor appetite
• Nose bleeds
• Seizures or coma in very severe AKI

Sometimes, acute kidney injury does not show any symptoms and is only found through tests done for other health problems. 

Why Does Acute Kidney Injury Happen?

Sudden kidney damage can occur due to 

• Conditions that cause poor blood flow in the kidneys for a period of time
• Blockages affecting ureters, the tubes which carry urine from the kidneys to the bladder
• Conditions that directly cause damage to the kidneys

Poor blood flow: Having severe diarrhea, infection, liver failure, serious burns, severe allergic reactions, heart diseases, or a heart attack can cause impaired blood flow to your kidneys. Bleeding too much or overusing non-steroidal anti-inflammatory drugs such as ibuprofen or aspirin can also cause poor blood flow. 

Direct damage to the kidneys: AKI can result from diseases affecting kidneys such as glomerulonephritis and lupus. Blood clots in the kidneys, infections such as COVID19, alcohol or drug abuse and medications such as cancer drugs and a few antibiotics can also damage your kidneys and lead to acute kidney injury. 

Blockage in the urinary tract: Blood clots in the kidneys, bladder problems, kidney stones, enlarged prostate, and some cancers (cervical, prostate, or bladder cancer) can block the excretion of urine from the body and lead to acute kidney injury. 

How Is Acute Kidney Failure Detected?

If your physician suspects that you may have acute kidney injury, he/ she will recommend some tests to confirm the diagnosis.

Urine test: Analysis of urine sample will reveal if any abnormalities associated with acute kidney injury present.

Blood tests: Blood tests will check the levels of creatinine and urea, waste products that your kidneys remove from the blood. 

Urine output test: Tracking how much you urinate in twenty-four hours will help find the cause of the kidney injury.

Imaging tests: Tests such as ultrasound and computerized tomography helps see kidneys. An ultrasound is the preferred option for diagnosing AKI.

Kidney biopsy: In certain instances, a doctor may use a special needle to remove a tiny piece of kidney sample and look under a microscope.

What Is The Treatment For Acute Kidney Injury?

The primary focus in the treatment for acute kidney injury lies in treating the underlying cause. If acute kidney injury is found and treated quickly, the kidneys may work normally or almost normally as it was before. 

• You may be given intravenous fluids and medicines like epinephrine to treat life-threatening symptoms (such as low blood pressure or shock).
• Dangerous potassium levels can lead to life-threatening cardiac arrhythmias. Drugs such as insulin, diuretics, and albuterol may be given to clear potassium from the body. Diuretics expel the extra fluids, which causes swelling in the legs and arms. 
• To normalize the urine flow, a thin tube called a urinary catheter is inserted into your bladder and will drain the urine from the bladder.
• Your doctor may prescribe antibiotic medications to control infections.
• You may be asked to stop taking suspected medications linked with AKI at least until the recovery

In severe cases, hemodialysis may be temporarily done to replace the kidney function. It helps eliminate waste products and excess fluids from the body. In dialysis, the blood passes through tubes from the body into the dialysis machine, where the blood gets filtered and the cleaned blood travels back into the body through tubes from the machine. 

During AKI you might stop urinating, have confusion, or your potassium levels are dangerously high. And this condition needs dialysis to recover.

During recovery, the physician may recommend you to take a special diet that helps prevent the accumulation of waste products. This will speed up the healing process. A diet which is low in potassium, sodium and protein is usually recommended in such cases. Your doctor may refer you to a dietitian who helps you to formulate a special diet plan that suits you.

The chances of developing kidney failure and kidney disorders increase every time acute kidney injury occurs. The risk of having other health problems such as heart disorders and stroke also increases. Follow up with your physician to lower your chances of kidney damage in the future. Read about the causes of kidney failure (end-stage renal disease). 

The Bottom Note:

It can be hard to prevent or predict acute kidney failure. But anyone can reduce the risk of AKI by taking good care of kidneys. Take the medicines exactly as recommended by your physician. 

Work with your health care professional to manage the existing health conditions such as high blood sugar, high blood pressure, or heart problems that could lead to acute renal failure. Stick with a diet low in salt and fat. Try to have at least 150 minutes of moderate to intense physical activity per week.