Acute Kidney Failure - Causes, Symptoms, Diagnosis, and Management

Introduction:

Acute kidney failure usually occurs when the kidneys lose their ability to filter blood and eliminate waste products from the body. As a result, the toxic substances accumulate in the blood resulting in a life-threatening condition known as blood poisoning (septicemia). Acute kidney failure is usually seen in critically ill people and requires emergency medical care and attention. The condition worsens if left untreated for a long time and causes permanent damage to the kidneys. Therefore, it is important to undergo the treatment at the earliest to prevent further complications.

What Is Acute Kidney Failure?

The kidneys are present in the urinary system, and when they stop working suddenly, the condition is known as acute kidney failure. It usually occurs when the person is suffering from a condition that interferes with the blood flow to the kidneys, and the tubes that drain the urine from the kidneys (ureters) are damaged. The following factors increase the risk of acute kidney failure:

• People above 60 years of age, critically ill, and undergoing treatment in the hospital for a long time are at the highest risk.

• People who have uncontrolled diabetes, hypertension (high blood pressure), heart diseases, and kidney diseases are likely to develop kidney failure.

• People who have undergone major surgery, usually bypass surgery, and cannot keep themselves hydrated suffer from kidney failure to a large extent.

• One of the risk factors for kidney failure is peripheral artery disease. In this condition, the arteries that carry the blood to the kidneys become narrow or are blocked, resulting in kidney damage.

What Are Some of the Causes of Acute Kidney Failure?

The causes of kidney failure have been described under three categories:

1) Reduced Blood Flow to the Kidneys: If the kidneys do not receive a continuous blood supply, they fail to function properly. As a result, the filtration of the blood stops, and the waste products remain within the body. The conditions which obstruct the passage of blood to the kidneys are listed below:

• Infection: The presence of infection makes it difficult for the heart to supply blood to the organs of the body. As a result, the vital organs of the body like the brain, kidneys, and liver do not receive blood and stop working.

• Hypovolemic Shock: In this condition, the blood and fluid loss from the body occur in large amounts resulting in reduced blood supply to the kidneys and other organs. The blood pressure becomes low in hypovolemic shock.

• Liver Failure: The risk of kidney failure increases if the liver fails to work because of the reduced blood flow to the kidneys and reduced rate of filtration of blood.

• Heart Diseases: The heart is the principal organ of the body because it supplies blood to all the body organs. Heart diseases reduce the abilities of the heart muscles to pump blood effectively. As a result, the kidneys do not receive enough blood and fail to work.

2) Nonsteroidal Anti-inflammatory Drugs (NSAIDs): The drugs that come under this category are mainly painkillers like Ibuprofen, Paracetamol, and Diclofenac Sodium. Overuse of these drugs interferes with the blood flow to the kidneys and causes retention of waste products that were to be eliminated.

3) Burns and Dehydration: Burn injuries and dehydration decrease blood volume, leading to the impaired blood supply to the organs.

4) Kidney Damage: The conditions that directly damage the kidneys are listed below:

• The kidneys consist of filters that work to remove the toxins from the blood. If these filters are damaged due to inflammation, the condition is known as glomerulonephritis. The kidneys fail to filter blood in this condition.

• Multiple myeloma or cancer of the immune system causes abnormal protein deposition in the kidneys, damaging them.

• Hemolytic uremic syndrome is a condition in which the blood vessels of the kidneys get damaged. As a result, the blood clots accumulate within the kidneys and block the kidney filters, which causes kidney failure.

• In scleroderma, the skin becomes hard and tight. If the condition becomes severe, blood pressure rises, leading to kidney damage.

• Toxins can build up in the kidneys because of the tumor cell breakdown (tumor lysis syndrome).

5) Obstruction in Urine Flow: If the urine does not flow freely and remains within the body, it can damage the kidneys. The following are the reasons for the restricted flow of urine:

• Enlargement of the Prostate: Prostate is present just beneath the bladder, and it has been commonly seen that with aging, the hormone level changes in men, and the prostate gland becomes enlarged, leading to the hindrance in the flow of urine out of the bladder.

• Presence of Kidney Stones: Normally, the presence of stones does not produce any symptoms, but when these stones get stuck within the tubes that drain the urine from the kidneys to the bladder, there is a backward flow of urine towards the urinary bladder resulting in severe pain.

• Blood in the Urine: Excessive blood in the urine can cause the formation of blood clots and blockage in the flow of urine from the bladder leading to severe pain.

• Presence of Tumor: Tumor is the uncontrolled growth of cells that can occur in almost any body organ. Any such tumor in the urinary system, like within the urethra or near the ureters, can obstruct urine flow.

What Are the Symptoms of Acute Kidney Failure?

The symptoms of acute kidney failure are listed below:

• Decrease in the urine flow as a result of which the urine output is less.

• The kidneys cannot filter the blood and the body fluids resulting in the accumulation of toxins within the body. Swelling of the ankles, legs, and feet occurs due to retained fluid and toxins.

• Failure of the kidneys to eliminate the fluid from the body causes it to accumulate in the lungs resulting in shortness of breath.

• The patient feels tired because of the failure of the kidneys to expel the waste products from the body.

• Chest pain occurs due to the collection of fluids in the lungs and inflammation of the heart lining.

• The volume of blood increases if the kidneys fail to work. As a result, the heart works under pressure leading to disturbance in the normal heart rhythm. As a result, the heartbeat becomes irregular.

• The patient might go into a coma if the condition becomes extensively severe.

How Is Acute Kidney Failure Diagnosed?

The following tests need to be done to diagnose acute kidney failure:

1. 24-Hour Urine Test: It is a laboratory test to examine urine contents and assess kidney function. The patient needs to collect the urine for 24 hours in a container, and it is then sent to the laboratory for analysis. This test gives the doctor an idea about the urine output. If the urine output is less than normal, kidney disease can be suspected.

2. Urinalysis: In this test, the urine collected by the patient is examined under a microscope in the laboratory. In case of infection, high amounts of white blood cells will be present in the urine.

3. Blood Tests: A blood test is usually recommended to measure creatinine and urea levels. Creatinine is a waste product produced by the muscles, and the breakdown of proteins forms urea. Both creatinine and urea are eliminated from the body by the kidneys. Therefore, if the levels of these two substances are high in the blood, kidney disease can be suspected.

4. Imaging Tests: The following imaging tests are also done to diagnose kidney infection:

• Computed Tomography (CT Scan): In this test, the images of the kidneys are obtained on the computer, and it helps the doctor examine the kidneys.

• Ultrasound: In this procedure, sound waves are sent to the kidney, and images are obtained. The doctor looks at the images on the computer. This image will give him an idea about the presence of stones, tumors, wounds, or anything that leads to kidney damage.

• Renal Biopsy: It is the procedure in which a needle is inserted into the skin to remove a small piece of kidney tissue. The tissue mass is then examined in the lab under a microscope for the presence of abnormalities.

How to Manage Acute Kidney Failure?

The patient is required to stay in the hospital during the treatment of acute renal failure. If the condition is diagnosed early, medication and dietary changes recommended by the doctor will be of great help. The treatment depends upon the causes of acute kidney failure. The treatment options are listed below:

• Intravenous Fluids (IV fluids): If the cause of acute kidney failure is the lack of fluids in the blood, they are injected into the body through the veins to maintain an optimum blood volume.

• Diuretics: Diuretics are the medications that eliminate fluid from the body that has accumulated due to kidney failure. Chlorthalidone, Hydrochlorothiazide, and Metolazone are the commonly used diuretics in kidney failure.

• Sodium Polystyrene Sulfonate: It is prescribed by the doctor if the potassium levels have increased in the body due to kidney failure. The heart becomes fast, and muscles become weak if the potassium accumulates in the body.

• Hemodialysis: It is a procedure in which a machine is attached to the body to remove blood. This blood is then filtered by the dialyzer (artificial kidney), and the fresh blood obtained is sent to the body. If the kidneys do not heal, the patient must repeatedly undergo dialysis.

• Kidney Transplant: A healthy kidney (donor's kidney) is transferred to the body to replace the infected one. The donor could be a friend or a family member.

How to Prevent Acute Kidney Failure?

The patient needs to follow a particular diet plan and introduce changes in his lifestyle to prevent acute kidney failure. The dietary changes to be observed are listed below:

1. Low potassium foods like apples, strawberries, cranberry, grapes, pineapples, and cabbage must be included. It is better to avoid high potassium foods like apricots, avocados, bananas, and dates as they can raise the potassium levels of the body.

2. Fast foods, snacks, canned soups, pizza, and sandwiches contain salts in large amounts. Therefore, these foods should be avoided as salts contain sodium which can accumulate in the body in kidney failure.

3. The phosphorus intake should also be restricted to prevent bones from getting weak. Bread, nuts, peanut butter, and whole grains contain a lot of phosphorus.

What Are the Complications of Kidney Failure?

The kidneys maintain the level of fluids in the body. In the case of kidney failure, the fluid remains retained within the organs of the body like the heart and lungs and causes symptoms of chest pain, difficulty in breathing, and swelling in the legs and ankle. Permanent kidney damage occurs if the condition is left untreated for a prolonged period. The kidneys completely lose their ability to work.

Conclusion:

Acute kidney failure is a condition that requires urgent medical care and attention. The condition develops suddenly and becomes life-threatening if the symptoms are ignored, and the treatment is not provided at the right time. The patient needs to remain on dialysis for a prolonged period if the condition persists. The patient should consult the doctor immediately and follow all the dietary recommendations after the treatment. Timely diagnosis and appropriate medicines help the kidneys return to normal, and the patient lives a healthy life ahead.