Classification and Causes of Kidney Failure
- Kidney failure can be classified as acute kidney failure or chronic kidney failure.
- Acute kidney failure develops rapidly and may resolve, while chronic kidney failure develops slowly and can often be irreversible.
- Symptoms of kidney failure include leg swelling, feeling tired, vomiting, loss of appetite, and confusion.
- Complications of kidney failure include uremia, hyperkalemia, volume overload, heart disease, high blood pressure, and anemia.
- Causes of kidney failure include low blood pressure, urinary tract blockage, certain medications, muscle breakdown, diabetes, high blood pressure, nephrotic syndrome, and polycystic kidney disease.
- Acute kidney failure can result from prerenal, intrinsic, or postrenal causes.
- Chronic kidney failure can also present as acute-on-chronic kidney failure, which may be reversible.
- The most common causes of chronic kidney failure are diabetes mellitus and long-term, uncontrolled hypertension.
- Polycystic kidney disease is another well-known cause.
- Chronic kidney failure can also be a consequence of other diseases or conditions.
- Drug overdoses or chemical overload can cause acute kidney injury, which may progress to chronic kidney failure.
- Crush syndrome, resulting from the release of toxins after the relief of pressure on a compressed limb, can also lead to chronic kidney failure.
- The APOL1 gene is a major genetic risk locus for renal failure in individuals of African origin.
- Two western African variants in APOL1 are associated with end stage kidney disease in African Americans and Hispanic Americans.
Symptoms and Diagnostic Approach
- Symptoms of kidney failure can vary from person to person.
- Early stage kidney disease may not cause noticeable symptoms.
- Azotemia, the accumulation of waste in the blood and body, can lead to symptoms.
- Symptoms of kidney failure include high levels of urea in the blood, vomiting or diarrhea, nausea, weight loss, and acute kidney injury.
- Acute kidney injury (AKI) occurs when the blood supply to the kidneys is suddenly interrupted or when the kidneys become overloaded with toxins.
- Chronic kidney failure is measured in five stages based on the glomerular filtration rate (GFR).
- Stage 1 CKD has mildly diminished renal function with few symptoms.
- Stages 2 and 3 require increasing levels of supportive care.
- Stage 4 and 5 kidney failure usually require active treatment such as dialysis or transplant.
- GFR is considered the best overall index of kidney function.
- Glomerular filtration rate (GFR) varies according to factors such as sex, age, body size, and ethnic background.
- GFR is calculated using a serum creatinine level.
- The National Kidney Foundation offers an online GFR calculator.
- GFR is used to determine the stage of kidney failure.
- A low GFR indicates reduced kidney function.
- The renal failure index (RFI) is calculated by multiplying urine sodium by plasma creatinine and dividing by urine creatinine.
- A renal failure index (RFI) greater than 3 is helpful in confirming acute renal failure.
- The fractional sodium excretion (FENa) index is another urinary index used in diagnosing renal failure.
- Both RFI and FENa scores are used to assess kidney function.
- Abnormal RFI and FENa scores indicate renal dysfunction.
Management and Treatment of Kidney Failure
- Protein diet restriction
- Vegetarianism in chronic kidney disease patients
- Safety of high-protein, vegetable-based diets for kidney function
- Early referral to specialist nephrology services
- Current medical diagnosis and treatment options
Complications of Kidney Failure
- Cardiovascular disease
- Anemia
- Bone disease
- Fluid overload
- Electrolyte imbalances
Prevention of Kidney Failure
- Control of arterial hypertension
- Avoidance of nephrotoxic medications
- Hygiene and prevention of hantavirus infection
- Genetic testing for MYH9-associated nephropathy and ApoL1 gene mutations
- Healthy lifestyle choices to maintain kidney health
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as either acute kidney failure, which develops rapidly and may resolve; and chronic kidney failure, which develops slowly and can often be irreversible. Symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion. Complications of acute and chronic failure include uremia, hyperkalaemia, and volume overload. Complications of chronic failure also include heart disease, high blood pressure, and anaemia.
| Kidney failure | |
|---|---|
| Other names | Renal failure, end-stage renal disease (ESRD), stage 5 chronic kidney disease |
 | |
| A hemodialysis machine which is used to replace the function of the kidneys | |
| Specialty | Nephrology |
| Symptoms | Leg swelling, feeling tired, loss of appetite, confusion |
| Complications | Acute: Uremia, high blood potassium, volume overload Chronic: Heart disease, high blood pressure, anemia |
| Types | Acute kidney failure, chronic kidney failure |
| Causes | Acute:
Chronic: |
| Diagnostic method | Acute: Chronic:
|
| Treatment | Acute: Depends on the cause Chronic: Hemodialysis, peritoneal dialysis, kidney transplant |
| Frequency | Acute: 3 per 1,000 per year Chronic: 1 per 1,000 (US) |
Causes of acute kidney failure include low blood pressure, blockage of the urinary tract, certain medications, muscle breakdown, and hemolytic uremic syndrome. Causes of chronic kidney failure include diabetes, high blood pressure, nephrotic syndrome, and polycystic kidney disease. Diagnosis of acute failure is often based on a combination of factors such as decreased urine production or increased serum creatinine. Diagnosis of chronic failure is based on a glomerular filtration rate (GFR) of less than 15 or the need for renal replacement therapy. It is also equivalent to stage 5 chronic kidney disease.
Treatment of acute failure depends on the underlying cause. Treatment of chronic failure may include hemodialysis, peritoneal dialysis, or a kidney transplant. Hemodialysis uses a machine to filter the blood outside the body. In peritoneal dialysis specific fluid is placed into the abdominal cavity and then drained, with this process being repeated multiple times per day. Kidney transplantation involves surgically placing a kidney from someone else and then taking immunosuppressant medication to prevent rejection. Other recommended measures from chronic disease include staying active and specific dietary changes. Depression is also common among patients with kidney failure, and is associated with poor outcomes including higher risk of kidney function decline, hospitalization, and death. A recent PCORI-funded study of patients with kidney failure receiving outpatient hemodialysis found similar effectiveness between nonpharmacological and pharmacological treatments for depression.
In the United States, acute failure affects about 3 per 1,000 people a year. Chronic failure affects about 1 in 1,000 people with 3 per 10,000 people newly developing the condition each year. Acute failure is often reversible while chronic failure often is not. With appropriate treatment many with chronic disease can continue working.
