Acute Kidney Injury (AKI): What You Need to Know
Acute kidney injury (AKI) is a sudden and rapid loss of kidney function that happens within a few hours or a few days. It can happen due to various causes such as severe infections, dehydration, medication side effects, or injury. AKI can cause serious health problems, such as fluid overload, electrolyte imbalance, waste accumulation, and organ failure. AKI is a medical emergency that needs immediate attention and treatment.
What are the symptoms of AKI?
Some of the symptoms of AKI may include:
– Reduced urine output
– Swelling of the legs, ankles, and feet
– Fatigue or tiredness
– Shortness of breath
– Confusion or mental changes
– Nausea or vomiting
– Chest pain or pressure
– Seizures or coma in severe cases
Some people with AKI may not have any symptoms and may only be diagnosed by blood or urine tests.
What are the causes of AKI?
AKI can be caused by three main factors:
– Decreased blood flow to the kidneys: This can happen due to low blood pressure, blood loss, heart failure, liver failure, dehydration, or some medications that affect kidney function.
– Direct damage to the kidneys: This can happen due to infections, inflammation, blood clots, toxins, drugs, or trauma that injure the kidney cells or tissues.
– Blockage of urine flow from the kidneys: This can happen due to kidney stones, tumors, enlarged prostate, blood clots, or other conditions that obstruct the urinary tract.
What are the stages of AKI?
AKI can be classified into four stages according to the KDIGO criteria:
– Stage 1: An increase in serum creatinine level by 0.3 mg/dL or more within 48 hours, or an increase by 1.5 times or more from the baseline within 7 days; or a urine output of less than 0.5 mL/kg/hour for 6 hours.
– Stage 2: An increase in serum creatinine level by 2 times or more from the baseline within 7 days; or a urine output of less than 0.5 mL/kg/hour for 12 hours.
– Stage 3: An increase in serum creatinine level by 3 times or more from the baseline within 7 days; or an increase to 4 mg/dL or more; or initiation of renal replacement therapy; or a urine output of less than 0.3 mL/kg/hour for 24 hours; or anuria (no urine output) for 12 hours.
– Stage 4: End-stage kidney failure requiring long-term dialysis or transplantation.
How is AKI diagnosed?
AKI is diagnosed by measuring the serum creatinine level and the urine output. Creatinine is a waste product that is normally filtered by the kidneys and excreted in the urine. When the kidneys are not working well, creatinine builds up in the blood and indicates reduced kidney function. Urine output reflects how much fluid and waste the kidneys are able to eliminate from the body.
Other tests that may be done to diagnose AKI include:
– Blood tests: To check for electrolyte levels, blood urea nitrogen (BUN), blood cell counts, and other indicators of kidney function and damage.
– Urine tests: To check for protein, blood, glucose, and other substances that may indicate kidney injury or infection.
– Ultrasound: To check for any blockage or abnormality in the kidneys or urinary tract.
– Kidney biopsy: To take a small sample of kidney tissue for microscopic examination and diagnosis.
How is AKI treated?
The treatment of AKI depends on the cause and severity of the condition. The main goals of treatment are:
– To treat the underlying cause of AKI: This may involve antibiotics for infections, fluids for dehydration, medications for blood pressure control, dialysis for toxin removal, surgery for obstruction relief, etc.
– To support the kidney function and prevent complications: This may involve fluid management, electrolyte replacement, nutritional support, blood transfusion, etc.
– To monitor the kidney recovery and prevent chronic kidney disease: This may involve regular blood and urine tests, follow-up visits, lifestyle changes, etc.
Some people with AKI may need temporary dialysis to help their kidneys filter waste and fluid from their blood until their kidney function improves. Dialysis is a procedure that uses a machine or a membrane to act as an artificial kidney. There are two main types of dialysis:
– Hemodialysis: A machine pumps blood through a filter that removes waste and excess fluid. The filtered blood is then returned to the body through a vein.
– Peritoneal dialysis: A fluid called dialysate is infused into the abdominal cavity through a catheter. The dialysate absorbs waste and excess fluid from the blood vessels that line the peritoneum (the membrane that covers the abdominal organs). The dialysate is then drained out through the catheter.
What is the outlook for AKI?
The outlook for AKI depends on the cause, severity, and duration of the condition, as well as the age and overall health of the person. Some people with AKI may recover completely and regain normal kidney function. Others may have some degree of permanent kidney damage and require long-term dialysis or transplantation. Some may die from AKI or its complications.
The mortality rate of AKI varies depending on the stage and setting of the condition. According to a 2019 review, the mortality rate of AKI in hospitalized patients ranges from 10% to 80%, with higher rates in ICU patients and those requiring dialysis. The mortality rate of AKI in community-acquired cases ranges from 5% to 25%.
How can AKI be prevented?
Some of the ways to prevent AKI include:
– Drinking enough fluids to stay hydrated
– Avoiding or limiting the use of NSAIDs and other medications that can affect kidney function
– Seeking medical attention for any signs of infection, dehydration, or injury
– Controlling blood pressure, blood sugar, and cholesterol levels
– Following a healthy diet and lifestyle
– Quitting smoking and limiting alcohol intake
– Getting regular check-ups and screening tests for kidney function
References:
– National Kidney Foundation. (2020). Acute Kidney Injury (AKI). https://www.kidney.org/atoz/content/AcuteKidneyInjury
– Medical News Today. (2021). Acute kidney injury: Symptoms, causes, treatment, and more. https://www.medicalnewstoday.com/articles/acute-kidney-injury
– StatsPearls. (2021). write my paper on Acute Kidney Injury. https://www.ncbi.nlm.nih.gov/books/NBK499997/
– MSN Health. (2021). What is Acute kidney injury and its possible symptoms, causes, risk and prevention methods? https://www.msn.com/en-us/health/condition/Acute-kidney-injury/hp-Acute-kidney-injury?source=conditioncdx
