ACUTE KIDNEY FAILURE
- How do kidneys form urine?
The kidneys filter blood through millions of capillary tufts called glomeruli. The substances that are essential for the body are retained and the rest (final products of metabolic activities, various other substances in body fluids and surplus water and electrolytes) are removed from the body; these wastes are passed out in urine through minute tubular structures called tubules into the ureters (muscular pipes leading from the kidney to the urinary bladder) and then into urinary bladder.
- What are the other functions of the kidneys?
The kidney helps to keep the internal environment constant through its excretory and regulatory function. It also produces hormones that are important for red blood cell formation (Erythropoietin), calcium metabolism (1,25-dihydroxycholecalciferol, a form of active vitamin D3) and control of blood pressure (Renin).
- What do mean by kidney failure?
Kidney failure is a medical condition in which the kidneys fail to perform the above mentioned functions adequately.
- How do you assess kidney function?
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).
- When we say kidney failure does it imply failure of one kidney or both kidneys?
When we say kidney failure, it implies the failure of both kidneys or the failure of the only existing kidney.
- What are the types of kidney failure?
Based on the onset and duration of kidney failure, it can be classified into acute kidney failure and chronic kidney disease (CKD).
- What is acute kidney failure?
Acute kidney failure is sudden (over a period of hours or days) decline in kidney function that results in increase in serum creatinine or decrease in urine output or both. The word “acute” means sudden. Patients with acute kidney failure are likely to recover kidney function completely or partially over a period of weeks depending on the cause and severity of kidney failure and the prior level of kidney function.
- What are the causes of acute kidney failure?
Acute kidney failure can be caused by: a) reduced blood flow to the kidneys resulting from heart failure, low blood pressure and reduced blood volume secondary to severe external or internal bleeding and dehydration, b) direct damage to the kidneys caused by infections, cancer, medicines, poisons, snake venom and autoimmune diseases in which a person’s infection fighting system (immune system) attacks one’s own body tissues and c) blockage of the urinary passage.
- What are the symptoms of acute kidney failure?
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.
- What tests do you perform for the diagnosis of acute kidney failure?
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.
- What are the complications of acute 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).
- How is acute kidney failure treated?
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.
- Should I be on diet restriction to improve kidney function?
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.
- Will I require dialysis?
You will require dialysis if kidney failure is severe and there are severe electrolyte and acid base abnormalities.
- How often will I require dialysis?
You will require dialysis on alternate day basis.
- What are the types of dialysis?
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.
- How long will it take for recovery of kidney function?
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.
- Will I have to be on dialysis until then?
The requirement for dialysis will be mostly temporary depending on the cause of renal failure and the scope for renal recovery.
- How will you decide if I continue to require dialysis or not?
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.
- Will I have complete recovery of kidney function?
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.
- What will happen if recovery of renal function is incomplete?
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.
- Is there a risk to the life of a patient having acute kidney failure?
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.