Causes,Symptoms and Diagnosis
What is Acute Kidney Injury (AKI)?
In acute kidney injury (previously acute renal 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 acute kidney injury?
There are many causes of AKI. Common causes include:
Symptoms of acute kidney injury
- 1. Reduced blood supply to the kidneys: severe dehydration due to
diarrhea, blood loss, burns or fall in blood pressure.
- 2. Severe infection, serious illness or after a major operation.
- 3. Sudden blockage of the passage of urine : Kidney stones is the most
common cause of urinary tract obstructions.
- 4. Other causes: Falciparum malaria, leptospirosis, snake bite, certain
kidney diseases, pregnancy, complications and side effects of some
medications (NSAIDs, aminoglycosides, radio contrast, certain
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.
- 1. Symptoms due to underlying condition (diarrhea, blood loss, fever,
chills, etc.) causing kidney failure;
- 2. Decreased urine output (urine output may remain normal in a few
- 3.Swelling of ankles or feet and weight gain due to fluid retention.
- 4. Loss of appetite, nausea, vomiting, hiccups, fatigue, lethargy and
- 5. 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.
- 6. 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 acute kidney injury
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 injury
In most patients, with proper management acute kidney injury can be
However delay or improper treatment of severe acute kidney failure
can be life-threatening.
CHP. 9. Acute Kidney Injury 39.
Major steps for the management of acute kidney injury are:
1. Correcting/ treating the causes of kidney injury:
- 1. Correction or treatment of the causes of kidney injury.
- 2. Drug therapy and supportive measures.
- 3. Dietary advice.
- 4. Dialysis.
2. Drug therapy and supportive measures:
- Identification and treatment of the underlying cause is the most
important aspect of management of acute kidney injury.
- Specific treatment of underlying causes such as hypotension, infection,
urinary tract obstruction etc. is essential for recovery from kidney
- Such therapy prevents further damage to the kidney and subsequently
allows it to recover.
- The goal is to support the kidneys and to prevent or treat any
- 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.
Supportive therapy: drugs are given which help to correct low or high
blood pressure, control nausea and vomiting, control blood potassium,
reduce breathlessness and prevent or control convulsions.
In acute kidney failure kidney usually recovers
completely with proper treatment.
40. Save Your Kidneys
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 edema and complications such as
- 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
- Restriction of salt intake. Salt restriction helps to reduce thirst, edema
and complications such as high blood pressure and breathlessness.
- Provision of adequate nutrition and calories.
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 : hemodialysis and peritoneal dialysis.
In AKI, the kidneys usually recover completely with proper treatment.
In acute kidney failure with early and proper drug
therapy kidney can recover without dialysis.
CHP. 9. Acute Kidney Injury 41.
When is dialysis needed in acute kidney injury?
Dialysis is needed in certain patients with severe forms of acute kidney
injury 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
Prevention of acute kidney injury
- Certain patients of acute kidney injury need temporary dialysis
(hemodialysis or peritoneal dialysis) support till kidney function
- Patients of acute kidney injury usually recover within 1 - 4 weeks,
during which dialysis support may be required.
- Dialysis treatment in AKI 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 injury.
- 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.
Need of dialysis is only for a few days, but
delay in dialysis can be life-threatening.