Every day a person uses various medications, comes into contact with chemicals, buys products in stores. Few people understand that poisoning directly with nitrates can provoke a disease such as methemoglobinemia. What it is?
Brief medical certificate
Hemoglobin is a complex protein that is part of red blood cells. It contains iron and is responsible for transporting oxygen to all elements of the body. Methemoglobinemia is a pathology accompanied by an increase in hemoglobin saturated with oxidized iron. Its development is accompanied by weakness and headaches, shortness of breath with increased loads.
Methemoglobin is a form of hemoglobin that has lost the ability to bind and transport oxygen. Normally, it should be formed in the process of metabolism, and in the body is present in small amounts. With an increase in its concentration, tissues begin to experience oxygen deficiency, responding to changes in a specific clinical picture.
Methemoglobinemia may be:
- Primary, or congenital. In this case, methemoglobin accounts for 20 to 50% of the total complex protein.
- Secondary. Methemoglobin concentration ranges from excessively low to dangerously high.
Depending on the causes of development, methemoglobinemia can be of exogenous or endogenous origin. In the first case, the disease occurs under the influence of external factors, and in the second, it is diagnosed in patients with impaired synthesis and absorption of nitrates.
The main causes and risk factors
The congenital form of the disease is hereditary and most often develops for the following reasons:
- Fermentopathy - a decrease in the activity of methemoglobin reductase. This is a special enzyme characterized by the ability to reduce oxidized iron.
- M hemoglobinopathy. Pathology is manifested by the synthesis of hemoglobin, in the composition of which oxidized iron is initially present.
Elevated levels of methemoglobin are diagnosed in all newborn babies. This phenomenon is considered a variant of the norm. It is due to the low activity of enzymes and the stress that the child experiences during childbirth. Over time, the situation usually normalizes.
The reasons for the development of human methemoglobinemia secondary are many. As elements that contribute to the oxidation of iron, the following can be distinguished:
- nitrates;
- chlorobenzene;
- aniline dyes;
- potassium permanganate;
- food and water contaminated with nitrates.
In addition, some drugs contribute to the development of the disease. For example, Paracetamol, Dapson, Vikasol, Nitroglycerin, Lidocaine, etc. However, you should not be afraid to take these medications, since a negative reaction is possible only with a significant overdose.
General clinical picture
Many people do not know what it is - methemoglobinemia. Meanwhile, the symptoms of the disease are diverse. Their manifestation depends on the condition of the patient, his age and the presence of chronic pathologies. Not the last role in this matter is played by the stage of development of the disease. In some, symptoms appear when the level of oxidized iron reaches 20%, while in others they are completely absent. Only a complete blood count in the latter case helps to reveal the picture of the pathological process.
Doctors distinguish common symptoms of methemoglobinemia:
- general malaise;
- discoloration of the skin to an earthy tint;
- dyspnea;
- frequent dizziness;
- leg cramps;
- sleep disturbance;
- nervousness;
- sharp mood swings.
Most people, with an increase in hemoglobin saturated with oxidized iron in the blood, have diarrhea and problems with stools.
Signs of water-nitrate methemoglobinemia
This form of the disease has specific characteristics. After poisoning with toxins, it begins to progress rapidly. After drinking even a small amount of contaminated water, the following symptoms may occur:
- blue skin;
- violation of orientation in space;
- headache.
If you do not seek medical help in a timely manner, the condition may worsen. In this case, shortness of breath and arrhythmia, convulsions appear in patients.
In adults, water-nitrate methemoglobinemia usually proceeds in a mild form. In children, it is accompanied by a digestive disorder. Small patients, especially those who are breast-fed, are more susceptible to the disease. When they prepare a mixture using contaminated water, the likelihood of developing serious pathological processes increases several times.
The course of the disease in children
In infants, signs of hereditary methemoglobinemia are noticeable immediately after birth. In these children, mucous membranes, skin of the lips, earlobes and nails are blue. As a rule, the disease is accompanied by a number of other disorders, among which the following are distinguished:
- underdevelopment of limbs;
- change in the normal shape of the skull;
- thalassemia - a disorder of hemoglobin synthesis;
- vaginal atresia (in girls);
- lag in psychomotor development.
Consult a doctor if you suspect a congenital methemoglobinemia. What is it and how to properly treat the disease, the doctor should tell at the reception.
Diagnostic Methods
Determining the presence of a pathological process in the body is quite simple. Methemoglobinemia is indicated by a brownish tint of blood, which does not change color when interacting with oxygen. If this test shows a positive result, a comprehensive examination is prescribed to confirm the preliminary diagnosis. It consists of the following activities:
- spectroscopy;
- general blood analysis;
- hemoglobin electrophoresis;
- blood chemistry.
In the case of a toxic form of pathology, the test with methylene blue is considered the most indicative. After the introduction of this substance, cyanosis usually disappears.
Therapy Features
Treatment of methemoglobinemia is not always required. For example, if an increase in the level of methemoglobin is caused by taking certain groups of drugs, they are simply canceled. Subsequently, all blood counts are normalized.
The main goal of a standard course of therapy is to convert oxidized iron to normal. For this, patients are prescribed the introduction of a solution of methylene blue ("Chromosmon"). As a rule, this measure is enough so that all unpleasant symptoms disappear after a few hours. Also, in the framework of drug therapy, blood transfusions and ascorbic acid are prescribed. In infants with enzymatic pathologies, riboflavin is supplemented with therapy.
Many pregnant women who have been diagnosed with methemoglobinemia (you already know what it is) do not realize that the disease is very serious. Symptoms of pathology are usually only exacerbated by toxicosis. Such ladies first of all need quality medical care. A prolonged course of the disease can provoke fetal hypoxia and various developmental abnormalities. Therapy in this case is selected individually.
In acute toxic methemoglobinemia, the causes are eliminated first. Then oxygen therapy is prescribed, during which the patient breathes concentrated oxygen. A similar approach to treatment ensures the normalization of metabolic processes and the subsequent destruction of pathological hemoglobin.
Prognosis for recovery
Methemoglobinemia disease has a favorable prognosis. Complications are possible only with a toxic form of pathology and untimely seeking medical help. In rare cases, a fatal outcome is likely.
Prevention Methods
Methemoglobinemia is a serious enough disease, which is unacceptable to ignore the symptoms. Is it possible to avoid its development?
Doctors agree that it is quite easy to prevent an ailment. To do this, you must follow a number of rules:
- Do not self-medicate, and take the prescribed drugs strictly according to the scheme;
- avoid direct contact with toxic substances;
- try not to eat foods grown with nitrates and contaminated water;
- consult a geneticist before conceiving a child.
The rules of prevention in the case of a congenital form of pathology are somewhat different. Doctors recommend avoiding hypothermia, limiting physical activity and periodically engage in strengthening immunity.