Acute renal failure

Generality

Acute renal failure is a serious medical condition characterized by a sudden decline in the functional capacity of the kidneys.

The causes of acute renal failure are numerous. These include circumstances such as, for example, myocardial infarction, glomerulonephritis or bladder cancer.

The symptomatology is very broad and is a reflection of the functional incapacities of the kidneys.

If the treatment is immediate and appropriate to the causes, there is good hope of restoring kidney function.

Short revision of the kidneys

Two in number, the kidneys are the main organs of the urinary or excretory apparatus.

The excretory apparatus is the set of anatomical organs and structures responsible for the production and elimination of urine .

Returning to the kidneys, these reside in the abdominal cavity, on the sides of the last thoracic vertebrae and the first lumbar vertebrae; they are symmetrical and have a shape that is very reminiscent of a bean.

The most important functions of the kidneys are:

Filter waste substances, harmful substances and foreign substances present in the blood and convert them into urine.
Adjust the hydro-saline balance of blood.
Adjust the acid-base balance of blood
Produce erythropoietin glycoprotein.

The anatomy of the kidneys is quite complex: the image below shows the main anatomical elements of a generic human kidney.

What is acute renal failure?

Acute renal failure is a serious medical condition that affects the kidneys and consists of a rapid and sudden decline in renal function.

In other words, the term acute renal failure refers to a circumstance in which the kidneys have lost their functional capabilities in a sudden and unexpected manner.

If treated promptly and adequately, acute renal failure has reversible effects . Its presence therefore does not exclude a recovery of renal function.

KIDNEY FAILURE: MEDICAL DEFINITION

With kidney failure, doctors intend an inability on the part of the kidneys to properly perform their functions.

ANOTHER TYPE OF RENAL FAILURE: THE CHRONIC FORM

Renal failure can also be established gradually, due to a slow evolution mechanism.

When the loss of renal function occurs with the aforementioned modalities, the doctors speak of chronic renal failure .

Unlike acute renal failure, chronic renal failure is a condition whose effects are irreversible and for which the treatments serve only to slow down its inexorable deterioration.

WHAT HAPPENS WHEN KIDNEYS WORK EVIL?

When the kidneys malfunction, various mechanisms are skipped:

The mechanism of disposal of waste substances present at the blood level. This involves the progressive accumulation of these substances and the consequent intoxication of the blood.
Two important parameters that describe the amount of waste substances accumulating in the blood are azotemia and creatininemia .
Azotemia is the concentration of non-protein nitrogen (or urea) in the blood; non-protein nitrogen is a waste product of protein metabolism.
Creatininemia, on the other hand, is the concentration of creatinine in the blood; creatinine is a waste product deriving from the metabolism of creatine in the muscles.
A high azotemia and, in the same way, an elevated creatininemia are indexes of a malfunction of the kidneys.
The mechanism of regulation of the hydro-saline balance of blood. This involves the accumulation of fluids (edema) in various parts of the body, for example in the legs or ankles.
The mechanism of regulation of the acid-base balance of blood. From this derives an alteration of the blood levels of electrolytes, such as phosphorus and potassium.
The production mechanism of erythropoietin.

Causes

The causes of acute renal failure are numerous and represent a rather complex topic.

To make it easier to understand and study, doctors have decided to divide them into three broad categories; categories that group three different types of trigger conditions:

Category 1: conditions that slow or block direct blood flow to the kidneys.
These conditions include:

Myocardial infarction (or heart attack);
Heart diseases ;
Liver failure ;
Inadequate intake of aspirin, ibuprofen, naproxen and other similar drugs;
Allergic reactions ;
Severe burns ;
Severe dehydration ;
Severe bleeding ;
Inadequate intake of hypotensive drugs.

Category 2: conditions or events that cause direct damage to the kidneys.
These conditions include:

The formation of blood clots in the arterial or venous blood vessels of the kidneys;
The formation of cholesterol deposits in renal blood vessels;
Glomerulonephritis ;
The so - called hemolytic-uremic syndrome ;
Infections of the kidneys;
Systemic lupus erythematosus ;
Intake of certain drugs, including chemotherapy and antibiotics, or other substances, such as contrast fluids and zoledronic acid;
Multiple myeloma ;
Scleroderma ;
Thrombotic thrombocytopenic purpura ;
Intoxications from alcohol, cocaine or heavy metals ;
Vasculitis .

Category 3: conditions that block the flow of urine inside the organs and structures of the excretory apparatus.
These conditions include:

Bladder cancer ;
The formation of blood clots in the urinary tract ;
Uterine cervical cancer, in women;
Colon cancer ;
Benign prostatic hypertrophy, in humans;
Kidney stones ;
Prostate cancer, in humans;
Damage to the nerve structures that control the bladder.

RISK FACTORS OF ACUTE RENAL FAILURE

The subjects most at risk of acute renal failure are: the elderly, diabetics, people suffering from hypertension, heart patients, carriers of a kidney disease, individuals with liver disease, people with high cholesterol levels blood and carriers of the so-called peripheral arterial disease.

Symptoms and Complications

The typical symptoms and signs of acute renal failure are:

Event	Consequence of:
Nausea Vomiting and diarrhea. They are often a reason for dehydration Frequent urination and light-colored urine, or, alternatively, reduced urination and dark urine Difficulty urinating Blood in the urine	High azotemia (hyperazotemia)
Cramps and muscle spasms	Phosphorus accumulation in the blood (hyperphosphataemia)
Cardiac rhythm abnormalities Muscular paralysis	Potassium accumulation in the blood (hyperkalemia)
Edema in the lower limbs (water retention) Dyspnea and chest pain, following pleural effusion and / or pericardial effusion	Accumulation of fluids in tissues
Sense of fatigue and weakness Drowsiness Memory problems and confusion Difficulty concentrating Dizziness	Lack of erythropoietin production and anemia arising
Hypertension Loss of appetite Convulsions Persistent hiccups Easy bruising, due to a marked tendency to bleeding	Failure to carry out other renal mechanisms

WHEN TO REFER TO THE DOCTOR?

The presence of the aforementioned manifestations must induce an individual to immediately contact his own doctor and consult with him about what to do.

Acute kidney failure is a medical condition that requires adequate and timely treatment. Otherwise, the patient's life is in serious danger.

COMPLICATIONS

Acute kidney failure is in itself a complication of other conditions or diseases.

Having said this, its further deterioration may coincide with: an aggravation of the edemas present; an aggravation of hyperkalemia with the appearance of serious cardiac arrhythmias, the need to undergo dialysis, finally, death, especially in the absence of adequate or timely treatment.

Diagnosis

For a correct diagnosis of acute renal failure and its triggering causes, the following are fundamental: physical examination, medical history, blood tests, urinalysis and some diagnostic imaging tests.

In some situations, the use of a renal biopsy may also be indispensable, as it is useful in clarifying the causes.

BLOOD ANALYSIS

Blood tests allow you to measure azotemia and creatininemia and understand, from these parameters, how the kidneys work.

URINE ANALYSIS

Urinalysis provides information on the causes and characteristics of kidney failure in an individual.

Treatment

The treatment of acute renal failure involves a therapy aimed at treating the causes ( causal therapy ), a therapy focused on improving the symptoms and complications ( symptomatic therapy ), dialysis and the adoption of a lifestyle appropriate to the circumstances in act.

As a rule, acute renal failure requires hospitalization of the patient until renal function is resumed.

In short, the purpose of treatments for acute renal failure is to eliminate the cause of the aforementioned condition and restore normal renal function .

ACUTE RENAL FAILURE: SYMPTOMATIC THERAPY

Generally, the symptomatic therapy that doctors adopt in case of acute renal failure includes:

The use of drugs against water retention (especially diuretics ).
The administration of drugs that prevent the accumulation of potassium in the blood ( sodium polystyrene sulfonate and the like).
The use of calcium infusions, to restore the normal concentration of calcium in the blood.

DIALYSIS

Briefly, dialysis is a treatment that artificially reproduces certain functions of the kidney, cleaning up the blood from excess waste products and water.

Figure: dialysis

LIFESTYLE AND HOMEMADE REMEDIES

Generally, every patient with acute renal failure receives precise instructions from their treating physician on what type of diet to adopt.

Keeping to the letter of the doctor's planned diet is a fundamental cornerstone of the therapeutic process.

The most common dietary recommendations include:

Avoid too salty foods.
Prefer foods low in potassium.
Limit the ingestion of protein-rich foods.
Limit foods that are high in phosphorus.

Prognosis

In the case of acute renal failure, the prognosis depends on the triggering causes, the timeliness of the diagnosis and treatments and, finally, on the general health conditions of the patient.

Prevention

Following a healthy lifestyle, treating even the least worrying of kidney problems and paying attention to the use of certain drugs are the main preventive measures against acute renal failure.