Chemical pneumonitis: what is it, causes, symptoms, treatment, prognosis

What is chemical pneumonitis?

Chemical pneumonitis Is an inflammation of the lungs caused by aspiration or inhalation of irritants. It is sometimes called “chemical pneumonia,” although it is not contagious. There are two main types of chemical pneumonitis: acute and chronic.

Irritants that can cause chemical pneumonitis include vomit, barium used in gastrointestinal imaging, chlorine gas (among other lung agents), gasoline or other petroleum distillates swallowed, pesticides swallowed or absorbed through the skin, gases from electroplating, smoke and other. The disease can also be caused by the use of inhalants. Mendelssohn's syndrome is a type of chemical pneumonitis.

Mineral oil should not be given by mouth to young children, pets, or people with coughs, hernias hiatal or nocturnal reflux, as it can cause complications such as lipoid pneumonia. Due to its low density, it is easily absorbed into the lungs, from where it cannot be removed by the body. In children, when aspirated, oil can interfere with normal breathing, resulting in brain cell death and irreversible paralysis and / or brain damage.

Sign and symptoms

Spicy:

• cough;
• labored breathing;
• hunger for air (feeling like there is not enough air);
• abnormal sounds in the lungs (moist, gurgling breathing);
• chest pain, tightness or burning.

Chronic:

• persistent cough;
• dyspnea (dyspnea);
• rapid breathing (tachypnea);
• increased susceptibility to respiratory diseases.

Symptoms of chronic chemical pneumonitis may or may not be present, and it may take months or years before they become noticeable.

Causes and risk factors

Chemical pneumonitis occurs when a substance that is toxic to the lungs is inhaled (aspirated). The problem is the result of irritation, not infection. The most common toxic substance aspirated is gastric juice, and therefore chemical pneumonitis can occur in a person whenever he aspirates vomit. Inhalation of vomit can occur if vomiting occurs in a person who has not yet fully regained consciousness, such as after an epileptic seizure or drug / drug or alcohol overdose, or when a person comes to their senses after anesthesia.

Chemical pneumonitis can also be caused by aspiration of oily laxatives (such as mineral oil, castor oil, and paraffin oil) and hydrocarbons (such as gasoline, kerosene, and petroleum products).

There are two types of pneumonitis:

• Acute pneumonitis occurs suddenly after inhalation of the substance.
• Long-term (chronic) pneumonitis occurs after prolonged exposure to low levels of this substance. This causes inflammation and can lead to lung stiffness. As a result, the lungs begin to lose their ability to deliver oxygen to the body. If left untreated, this condition can cause respiratory distress and death.

Diagnostics

The diagnosis of chemical pneumonitis to physicians is usually clear from the sequence of events, if information about them is available. A chest x-ray and measuring the amount of oxygen and carbon dioxide in the blood sample can help in making the diagnosis.

An initial chest x-ray can remain normal for 48 hours, so delayed chest x-rays are important when exposure is significant. The most common x-ray presentation is pulmonary edema, although various x-ray opacities have been reported.

Treatment and prevention

Treatment for chemical pneumonitis consists of oxygen therapy and, if necessary, temporary artificial ventilation of the lungs with a breathing apparatus through a tube inserted into the throat. To remove secretions and aspirated food particles from the airways, suction through the windpipe (trachea) is possible. To achieve this, bronchoscopy (visual inspection of the airway through a flexible tube with an optical system) can be used.

Despite the fact that antibiotics are usually ineffective for this disease, they are often prescribed because doctors cannot clearly distinguish chemical pneumonitis from bacterial aspiration pneumonia, while often bacterial pneumonia can develop as a complication of chemical pneumonitis.

To help prevent chemical pneumonitis in people at risk, doctors may recommend a variety of strategies. These include withdrawal or dose reduction of anti-anxiety medications. They may also suggest raising the head of the bed slightly to prevent food, liquid, or acid from the stomach from entering the throat and then down into the lungs. To reduce the risk of aspiration, patients may need to eat only a certain consistency of food or drink condensed liquids. A speech therapist can teach people specific swallowing techniques (such as swallowing while pressing the chin against the chest) to reduce the risk of food and fluid getting into the lungs.

Forecast

In an original series of works by Curtis Lester Mendelssohn in 1946, Mendelssohn described 61 obstetric patients who aspirated stomach acid during anesthesia, and they all recovered fully clinically within 24-36 hours. Subsequent studies in older patients reported chemical pneumonia mortality from 30 to 62%, because chemical pneumonia often leads to acute respiratory distress syndrome (ARDS). The death rate from severe chemical pneumonitis (Mendelssohn's syndrome) can be as high as 70%.

Complications

Acute complications include secondary pneumonia. Long-term complications include, acute respiratory distress syndrome, bronchiectasisobliterating bronchiolitis and destruction of the lungs.