Acute Kidney Failure

What is Kidney Failure?

Our kidneys perform several functions in order to maintain balance in our bodies. They filter waste products and excrete them in the urine. They adjust the amounts of water and electrolytes like sodium, potassium and calcium in the body. They also help excrete excess acid or alkali, maintaining acid base balance. A reduction in their ability to perform these tasks is called kidney/renal failure.

How to diagnose kidney failure?

When both kidneys fail, there is a build-up of waste products in the blood, the easiest of which to measure in the laboratory being creatinine and urea. Formulas to estimate kidney function or glomerular filtration rate (GFR) using the serum creatinine are easily accessed on-line or in apps. Importantly, even a slight rise in the serum creatinine reflects a significant decrease in kidney function. A value of just 1.6 mg/dl may indicate over 50% loss of kidney function.

Can failure of one Kidney lead to kidney failure?

No. When only one of two kidneys fails or is removed, overall kidney function may not be significantly affected. The remaining kidney may compensate and take over the workload of both kidneys.

Kidney failure means loss of functions of both kidneys.

Two major types of kidney failure

Kidney failure may either be acute or chronic in nature.

Acute Kidney Failure

Acute insults to the kidneys may cause a reduction or loss in their function within a short period of time like a few hours to days. This decline in function was previously called Acute Renal Failure (ARF) but has been recently named Acute Kidney Injury (AKI)

This type of kidney failure is usually temporary. With proper treatment kidney functions return to normal in most patients.

Chronic Kidney Failure

Gradual progressive and irreversible loss of kidney function over several months to years is called chronic kidney disease (CKD), (previously known as chronic renal failure or CRF). Declining kidney function may reach a stage when the kidneys stop working almost completely. This advanced and life-threatening stage of disease is called end stage kidney disease - ESKD (End Stage Renal Disease or ESRD).

When kidney failure is diagnosed, over 50% of kidney function is already lost.

Acute Kidney Failure

What is Acute KidneyFailure ?

In Acute Kidney Failure ,reduction or loss of kidney functions occur within a short period (over hours, days or weeks) and is temporary, and usually reversible.

What causes AcuteKidneyFailure?

• There are many causes of AKF. Common causes include:
• Reduced blood supply to the kidneys: severe dehydration due to diarrhoea, blood loss, burns or fall in blood pressure.
• Severe infection, serious illness or after a major operation.
• Sudden blockage of the passage of urine : Kidney stones is the most common cause of urinary tract obstructions.
• Other causes: Falciparum malaria, leptospirosis, snake bite, certain kidney diseases, pregnancy, complications and side effects of some medications (NSAIDs, aminoglycosides, radio contrast, certain herbal concoctions.

Symptoms of acute kidney injury

• In AKI, due to the sudden interruption in kidney function and rapid accumulation of waste products and disturbances in fluid and electrolyte balance, the patient develops early and significant symptoms.
• The type of symptoms and their severity differ from patient to patient. These include:
• Symptoms due to underlying condition (diarrhoea, blood loss, fever, chills, etc.) causing kidneyfailure;
• Decreased urine output (urine output may remain normal in a few patients).
• Swelling of ankles or feet and weight gain due to fluid retention.
• Loss of appetite, nausea, vomiting, hiccups, fatigue, lethargy and confusion.
• Severe and life threatening symptoms such as breathlessness, chest pain, convulsions or coma, vomiting of blood and abnormal heart rhythm due to high blood potassium levels.
• In the early stage of acute kidney failure some patients are symptom- free and the disease is detected incidentally when blood tests are done for other reasons.

Acute kidney failure is a rapid and usually temporary loss of kidney functions.

Diagnosis of AcuteKidney Failure

Many patients with acute kidney injury have nonspecific symptoms or are asymptomatic. Therefore, in any setting or condition when AKI may develop or in the case of slightest doubt regarding symptoms, one must always suspect and investigate for acute kidney injury.

Diagnosis is confirmed by blood tests (rise in serum creatinine and blood urea), urine output measurements, urinalysis and ultrasound. In patients with acute kidney injury detailed history, examination and different investigations are performed to evaluate causes, complications and progression of the disease.

Symptoms of acute kidney failure are due to both underlying causes and severe kidney problems.

Treatment and Prevention

Treatment of Acute Kidney Failure

In most patients, with proper management acute kidney failure can be reversed. However delay or improper treatment of severe acute kidney failure can be life-threatening.

Major steps for the management of Acute Kidney Failure are:

• Correction or treatment of the causes of kidney failure.
• Drug therapy and supportive measures.
• Dietary advice.
• Dialysis.

1. Correcting/ treating the causes of kidney failure:

• Identification and treatment of the underlying cause is the most important aspect of management of acute kidney failure.
• Specific treatment of underlying causes such as hypotension, infection, urinary tract obstruction etc. is essential for recovery from kidney failure.
• Such therapy prevents further damage to the kidney and subsequently allows it to recover.

2. Drug therapy and supportive measures:

• The goal is to support the kidneys and to prevent or treat any complications.
• Treatment of infections and avoidance of drugs which are toxic and harmful to the kidney (e.g. NSAIDs).
• The use of diuretics such as furosemide help to increase the volume of urine and prevent accumulation of fluid in the body especially the lungs which is a cause of breathlessness.

In acute kidney failure kidney usually recovers completely with proper treatment.

3. Dietary advice

• Proper dietary restriction prevents or reduces symptoms or complications of acute kidney injury.
• Measurement of fluid intake. Daily fluid intake should be planned, keeping in mind urine volume and body fluid status. Usually, restriction of fluid is necessary to prevent oedema and complications such as breathlessness.
• Restriction of potassium intake. Avoid potassium-rich food e.g. fruits, fruit juices, dry fruits etc. to prevent high potassium level in blood (hyperkalemia), which is a very serious and life-threatening complication.
• Restriction of salt intake. Salt restriction helps to reduce thirst, oedema and complications such as high blood pressure and breathlessness.
• Provision of adequate nutrition and calories.

4. Dialysis

Short-term replacement of the kidney function by dialysis (artificial kidney) may be necessary in a few patients of acute kidney failure until the kidneys recover their functions.

What is dialysis?

Dialysis is the artificial process to replicate the functions of the damaged kidney. It helps to sustain life in people with severe kidney failure. The most important functions of dialysis are to remove wastes, remove excess fluid and correct acidosis and electrolyte disturbances.

There are two main types of dialysis : haemodialysis and peritoneal dialysis.

In AKF, the kidneys usually recover completely with proper treatment.

In acute kidney failure with early and proper drug therapy kidney can recover without dialysis.

When is dialysis needed in acute kidney failure ?

Dialysis is needed in certain patients with severe forms of acute kidney failure when increasing symptoms and complications occur despite adequate conservative management. Severe fluid overload, uncontrollable hyperkalemia and severe acidosis are the most common indications of dialysis in acute kidney injury.

For how long is dialysis treatment needed in acute kidney failure?

Certain patients of acute kidney failure need temporary dialysis (haemodialysis or peritoneal dialysis) support till kidney function recovers. Patients of acute kidney failure usually recover within 1 - 4 weeks, during which dialysis support may be required. Dialysis treatment is often temporary since the kidneys eventually recover in most cases delaying dialysis because of fear of permanent dialysis can be life-threatening in acute kidney failure.

Prevention of acute kidney failure

• Early treatment of potential causes and frequent check up of kidney function in such patients.
• Prevention of hypotension and its prompt correction.
• Avoidance of nephrotoxic drugs and prompt treatment of infection and reduced urine volume.
• Prevention of hypotension and its prompt correction.
• Avoidance of nephrotoxic drugs and prompt treatment of infection and reduced urine volume.

Need of dialysis is only for a few days, but delay in dialysis can be life-threatening.