What is azotemia (hyperazotemia): causes, symptoms, diagnosis, treatment

What is azotemia?

Azotemia is a type of nephrotoxicity that involves excess nitrogen compounds in the blood. In severe cases, it can negatively affect the kidneys and cause acute kidney failure.

Azotemia is a common condition, occurring in approximately 1% of all hospital admissions . There is an even higher incidence of 5% in hospital patients. The incidence of azotemia is highest in people aged 45 to 64 years.

Why do you need a nitrite test?

An example of test strips that, among other things, allow you to perform an analysis for nitrites.
But his results are considered very reliable. The price varies, but you can buy them very inexpensively (from about 4 dollars for 50 pieces). First of all, you need to understand that we are talking about an express test. That is, about receiving a “yes-no” answer. Either there are bacteria or there aren't. The researcher does not know exactly how many bacteria and what they are, what antibiotics they are sensitive to, or in which part of the urinary system they multiply. Therefore, no, even a very modern test strip for detecting nitrites will replace the same “banal” general urine test. Moreover, if the infection is caused by gram-positive bacteria and pseudomonads (and this happens quite often), nitrites will not be detected at all, because these two families of microorganisms do not process nitrates. But a lot of troubles are caused to a person (cystitis caused by gram-positive bacteria usually becomes chronic and difficult to treat).

Indications and contraindications for analysis

A general urine test, which shows the presence or absence of nitrites, is prescribed for almost all diseases (not only the urinary system), during monitoring of the treatment of pathologies, as well as screening studies. Urine analysis is an effective method for diagnosing various pathologies of the human excretory system.

Healthy individuals are recommended to take a urine test twice a year, and patients - as prescribed by a doctor. If a patient comes to see a urologist, then a general urine test is an integral part of the diagnosis.

Other indicators play an important role; nitrites are often used to determine the level of leukocytes in the urine. They are white blood cells and perform a protective function. Their rate should not exceed 1–4; other indicators indicate inflammatory processes or that the biomaterial was collected incorrectly. The patient has no contraindications to the analysis of urine nitrites; there are only rules for collecting and preparing for the study to obtain accurate results.

What does a positive test result mean?

Nitrates in the urine are not a sign of pathology, and the appearance of nitrites is a reason to prescribe further examination of the urinary system. Bacterial infection in women can cause serious diseases:

cystitis - inflammation of the bladder;
urethritis - an inflammatory process in the urethra;
pyelonephritis - bacterial inflammation of the renal pelvis, calyces and structural tissue of the organ.

The detection of nitrites in men can be caused by no less serious pathologies of the urinary system:

prostate adenoma, prostatitis;
cystitis;
pyelonephritis;
urethritis, which often occurs against the background of urolithiasis.

Due to the anatomical differences in the structure of the female and male urinary systems, women are more susceptible to bladder diseases. A short urethra allows bacteria to quickly enter and multiply, which is the cause of cystitis. Men are more often diagnosed with urolithiasis, since the removal of formed salts and stones is more difficult.

Types of azotemia

There are several different types of azotemia, which are classified according to the area of the renal system affected.

Prerenal azotemia is excess nitrogen in the blood caused by a lack of blood flow to the kidneys due to long-term low blood pressure or irregular heart function. This is the most common cause of acute kidney failure and can be corrected by restoring normal blood flow to the kidneys.
Intrarenal azotemia is a condition caused by too much nitrogen in the blood, resulting from damage to the kidneys that affects their ability to produce nitrogen in the urine. There are several medications that can trigger this kidney injury, including aminoglycoside antibiotics, antifungals, chemotherapy agents, biologic therapies, ACE inhibitors, intravenous contrast agents, and nonsteroidal anti-inflammatory drugs (NSAIDs). Certain health conditions can also cause this condition, such as diabetes and pyelonephritis.
Postrenal azotemia: Excess nitrogen in the blood caused by a kidney blockage that prevents urine from being cleared from the renal system. This may be the result of an obstruction resulting from, for example, stones, infection, tumor or enlargement of the prostate gland.

Features of pathology and its types

Azotemia or hyperazotemia is characterized by a decrease in the glomerular filtration rate of the kidneys, an increase in the concentration of residual nitrogen in the blood, or an increase in the parameters of urea and creatinine.

There are 3 main types of pathology:

Renal . The disease develops against the background of acute tubular necrosis, glomerulonephritis, and renal failure at the acute stage. The same thing happens after chemicals, toxins, and nephrotoxic poisons enter the body. The risk of developing uremia increases. Toxic substances accumulate in the patient’s body, which worsen his condition.
Prerenal . Pathological processes develop against the background of impaired blood circulation. Heart failure, hemorrhage, and shock also lead to prerenal azotemia.
Postrenal . The disease develops against the background of the formation of stones in the ureter and malignant tumors. We are talking about mechanical barriers that do not allow urine to escape.

A full examination and consultation with a doctor is necessary to establish an accurate diagnosis and undergo appropriate treatment.

Symptoms and signs

Signs and symptoms of azotemia may include:

infrequent urination;
painful urination;
blood in the urine and changes in urine color (such as dark amber or red);
fatigue;
muscle weakness;
peripheral edema;
nausea or vomiting;
lack of appetite;
fog.

Fever (fever) or chills may also occur if there is a concomitant infection.

Symptoms accompanying this disease

Symptoms of hyperazotemia depend on the reasons that provoked the development of pathological processes. The doctor needs to establish an accurate diagnosis, taking into account the patients’ complaints.

Signs of azotemia:

cardiopalmus;
the appearance of edema;
bleeding;
changes in blood pressure;
poisoning of the body with substances that are not excreted in the urine;
dry mouth;
constant desire to drink;
urine formation worsens against the background of the development of pathological processes in the kidneys.

Additionally, patients complain of vomiting, stool disorders, anemia and bad breath. Patients experience mood changes, constant drowsiness, and breathing problems. Tremors and convulsions also appear, and the mood is depressed. The skin becomes dry and severe itching occurs.

Signs of azotemia include general weakness in the body, lethargy and apathy towards the outside world. Timely diagnosis and treatment will avoid serious complications.

Treatment of azotemia

The main goal of treating azotemia is to quickly correct the cause of the imbalance before the kidneys become damaged or fail. The patient may be given intravenous fluids to increase blood volume. Several pharmacological treatments can be used to control certain factors that may have caused the condition. These include:

Amifostine: to reduce toxicity associated with chemotherapeutic agents;
Antibiotics: to eliminate infection that may have caused azotemia;
Insulin: to regulate blood glucose levels that could cause azotemia;
Loop diuretics: to release excess accumulated fluid in the body;
Sodium polystyrene sulfonates: to reduce potassium concentrations in the blood.

In addition, some doctors recommend a special diet for people with impaired kidney function to promote healthy kidney function and prevent damage. This may include:

Reduce your carbohydrate intake to control blood glucose levels;
Control protein intake to 15-20% of the total diet;
Increasing vegetable and fiber intake to support bowel habits;
Avoid excess potassium and magnesium.

Diagnostic measures

Patients with these clinical signs should consult a urologist. The doctor will conduct a medical examination, take into account the person’s complaints, and establish a preliminary diagnosis. If necessary, he will prescribe additional examination:

determination of urea nitrogen index and creatinine;
blood chemistry;
ultrasound diagnostics of the kidneys and genitourinary system;
general urine analysis;
MRI of the pelvic organs.

Taking into account the factors that provoked the development of pathological processes, the doctor may prescribe an additional analysis of daily diuresis and refer for bacterial culture.

Why are nitrites in urine dangerous during pregnancy?

During pregnancy, bacterial diseases of the urinary system pose a threat to the health of both the expectant mother and the child. Complications of such pathologies can result in dangerous consequences:

abortions, premature births;
transfer of bacterial infection to the organs of the reproductive system, infection of the fetus;
hypoxia in newborns - insufficient supply of oxygen to tissues, including the brain;
eclampsia is a sharp increase in blood pressure, which is accompanied by edema and convulsions.

Infectious diseases of the mother during pregnancy can cause the child to be underweight at birth, have a weak immune system, and be susceptible to viral and bacterial diseases.

Are nitrites in the urine different in women and men?

Of course no. Both the bacteria and the nitrites produced by these bacteria are exactly the same. The male and female urinary systems differ only in the final section: the urethra in women is short and relatively wide, and in men it is long and narrow. That is why laboratories make allowances for the different degrees of contamination of the material submitted by men and women. The contamination of the sample is of fundamental importance because during storage (for example, while awaiting transportation to the laboratory), bacteria first actively multiply, absorbing nitrates, and then die from a lack of nutrients, which is why the amount of nitrites also gradually decreases. The reliability of the result also changes.

Women are more likely to get bacteria into the bladder because they have a shorter urethra. This makes it easier for bacteria to enter the bladder. Some of the fair sex may encounter a similar problem 3 times a year.