Acute Renal Failure (ARF, AKI)

Acute renal failure, also known as acute kidney injury (AKI), is a sudden and abrupt loss of kidney function that occurs within hours to days. It is a medical emergency that requires prompt diagnosis and management to prevent long-term kidney damage or death. In this article, we will discuss the pathophysiology, signs, symptoms, investigations, treatment, and advice related to acute renal failure.

Mr. X, a 45-year-old man, was brought to the emergency department with complaints of nausea, vomiting, and decreased urine output for the past 24 hours. He had a history of hypertension and was on antihypertensive medication for the last five years. He denied any recent medication use or significant medical illness. On examination, he appeared dehydrated, and his blood pressure was 160/100 mmHg. His laboratory investigations showed elevated serum creatinine levels (4.5 mg/dl) and low urine output (less than 400 ml/day). A diagnosis of acute renal failure was made, and he was admitted for further management.

Acute renal failure can occur due to various reasons, including decreased blood flow to the kidneys (prerenal), direct damage to the kidneys (intrinsic), or obstruction of urine flow (postrenal). The most common cause of prerenal AKI is dehydration, which leads to decreased blood volume and decreased blood flow to the kidneys. Intrinsic AKI can occur due to various causes, such as glomerulonephritis, acute tubular necrosis, or drug-induced nephrotoxicity. Postrenal AKI is caused by obstruction of urine flow due to conditions such as kidney stones, tumors, or prostate enlargement.

Signs and symptoms:
The signs and symptoms of acute renal failure can vary depending on the underlying cause and the severity of kidney damage. Common signs and symptoms include:

Decreased urine output
Fluid retention and swelling in the legs, ankles, or feet
Nausea, vomiting, and loss of appetite
Fatigue, weakness, and confusion
Shortness of breath and chest pain (in severe cases)
High blood pressure (in some cases)
Abdominal pain and discomfort (in cases of obstruction)
The diagnosis of acute renal failure is based on clinical presentation and laboratory investigations. The following tests are usually performed:

Blood tests to measure serum creatinine and blood urea nitrogen levels
Urine tests to measure urine output, proteinuria, and urinary sediment
Imaging studies, such as ultrasound or CT scan, to evaluate the kidneys and urinary tract
Kidney biopsy (in some cases) to determine the underlying cause of kidney injury
The treatment of acute renal failure depends on the underlying cause and the severity of kidney damage. The following interventions are usually recommended:

Correction of fluid and electrolyte imbalances
Optimization of blood pressure control
Discontinuation of nephrotoxic drugs or other offending agents
Treatment of underlying infections or inflammatory conditions
Dialysis (in severe cases)
Advice (Dos and Don’ts):
Patients with acute renal failure should follow the following advice:


Drink plenty of water and other fluids (as advised by the doctor)
Follow a low-sodium diet to prevent fluid retention
Take medications as prescribed by the doctor
Monitor blood pressure regularly
Report any symptoms or changes in urine output to the doctor

Do not take any over-the-counter medications without consulting the doctor
Do not consume alcohol or caffeine
Do not smoke
Do not engage in strenuous physical activity without consulting the doctor
5. Do not delay seeking medical attention in case of any worsening symptoms or complications.

It is important to note that the prevention of acute renal failure is crucial in maintaining good kidney health. The following measures can help prevent the development of AKI:

Stay hydrated by drinking plenty of fluids, especially in hot weather or during physical activity.
Avoid the use of nephrotoxic drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or certain antibiotics.
Control underlying medical conditions, such as high blood pressure or diabetes, through regular monitoring and treatment.
Follow a healthy diet that is low in salt, sugar, and saturated fats.
Maintain a healthy weight and engage in regular physical activity.
In conclusion, acute renal failure is a serious medical condition that requires prompt diagnosis and management. Early recognition of symptoms and timely intervention can help prevent long-term kidney damage and improve patient outcomes. Patients with AKI should follow the advice of their healthcare provider and take steps to prevent the development of kidney disease.


KDIGO Clinical Practice Guidelines for Acute Kidney Injury. Kidney International Supplements, Volume 2, Issue 1, March 2012, Pages 1-138.
Ronco C, Bellomo R, Kellum JA. Acute Kidney Injury. Lancet. 2019 Aug 24;394(10212):1949-1964. doi: 10.1016/S0140-6736(19)32563-2. Epub 2019 Aug 21. PMID: 31447385.
National Kidney Foundation. Acute Kidney Injury. Accessed on March 25, 2023.

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