Kidney function is mainly assessed by the rate at which they filter waste products from blood into urine (glomerular filtration rate – GFR). Measurement of GFR is difficult; instead we use serum creatinine for this purpose. GFR can be calculated using certain mathematical formulae that require serum creatinine and certain other parameters (age, sex, race and weight).
Some people do not have any symptoms and are detected to have acute kidney failure after they have blood tests for another reason.
When people do have symptoms, the symptoms can include: reduced or absent urine output; red or brown urine; swelling, especially in the legs or feet; vomiting; not feeling hungry; tiredness; confusion; involuntary shaking or jerking muscle movements that may or may not be associated with loss of consciousness.
Acute kidney failure is diagnosed by estimation of serum creatinine. Further blood and urine tests along with ultrasound abdomen (a scanning test in which we get pictures of internal body organs by keeping a sensor over the area to be studied) are needed to find the associated abnormalities and to diagnose the cause of renal failure. If the cause of acute kidney failure is not clear from these tests, you may require computed tomography (CT) of abdomen and kidney biopsy. For a biopsy, the doctor will put a needle into your kidney and remove a tiny sample of tissue. Then another doctor (pathologist) will look at the sample under a microscope and diagnose the cause of kidney failure.
Patients with acute kidney failure may develop infection, bleeding into the stomach and intestine and cardiac disease during the course of illness. Apart from these complications, the cause of acute kidney failure can by itself cause failure of other organs (lung, heart, liver, brain, clotting system etc).
Treatment depends on what is causing acute kidney failure and how severe the kidney failure is.
If acute kidney failure is caused by a medicine, your doctor will stop that medicine and may give you steroid to help your kidneys heal.
If acute kidney failure has a treatable cause, your doctor will treat it. For example, reduced blood pressure or body fluid volume will require cessation of medications for high blood pressure (if you are taking before) and replacement of fluids. Infections require treatment with antibiotics. Autoimmune disorders may respond to treatment with steroids and other medications to suppress immunity.
If there is a block in the urinary tract, you may require insertion of tube into the urinary bladder or the ureter or directly into the kidneys depending on the level of obstruction.
Until the kidneys work normally again, the doctor will advise change in diet to make sure that you do not develop fluid retention and electrolyte and acid disturbances. Depending on the cause of kidney failure, urine output and electrolyte abnormalities, you will be prescribed a diet that has the right amount of fluid, salt and nutrient.
You will require dialysis if kidney failure is severe and there are severe electrolyte and acid-base abnormalities.
The types of dialysis are a) hemodialysis: a procedure in which a machine takes over the excretory function of the kidneys. The machine pumps blood out of the body and then filters the blood and returns it to the body; b) peritoneal dialysis: It involves piping a special fluid into the abdomen. This fluid collects waste and excess salt and water from the blood within capillaries in the abdomen. Then the used fluid drains out of the abdomen.
Most of the time, a person’s kidneys will heal and work again in 3 to 4 weeks’ time. But it may take weeks to months for complete recovery.
The requirement for dialysis will be mostly temporary depending on the cause of renal failure and the scope for renal recovery.
You will require dialysis until you have urine output sufficient enough to prevent weight gain and stabilization or improvement of pre dialysis serum creatinine and electrolyte and acid values.
Recovery of renal function is likely to be partial if the patient is elderly, kidney failure is severe requiring dialysis, the cause is an immune system disorder or the kidney function was subnormal prior to the current illness.
If renal recovery incomplete, you will have serum creatinine higher than normal. You will not require dialysis but will require regular monitoring and management for CKD.
Acute kidney failure involves risk to life and this risk is multiplied several times in the presence of failure of other organs (lung, heart, liver, brain, clotting system etc.). With dialysis, this risk can be brought down to some extent.