Bronchospasm is a pathological condition that occurs as a result of narrowing of the bronchial lumen of medium and small caliber, caused by spasm of smooth muscle fibers, swelling of the mucous membrane and violation of the drainage function of the respiratory tract. It is manifested by a feeling of lack of air, expiratory shortness of breath, unproductive or unproductive paroxysmal cough. Diagnosis of the syndrome is based on clinical data, physical and functional studies. Pathogenetic conservative therapy with bronchodilators, antihistamines and corticosteroids is carried out.
J98.8 Other specified respiratory disorders
Bronchospasm (bronchospastic syndrome, bronchiolospasm) is a symptom complex that characterizes the course of a number of diseases of the respiratory tract that occur with allergic reactions, certain intoxications and other conditions. Medical workers most often encounter this syndrome in patients with bronchial asthma, who make up 5-10% of the population. Allergic bronchospasm occurs in 2% of cases of all forms of drug intolerance. Airway obstruction occurs in 5% of people with significant physical exertion, among athletes this figure reaches 25%. A great danger to the patient’s life is the total narrowing of the bronchial lumen during anesthesia.
Bronchospastic syndrome is a polyethological pathology. Primary bronchospasm as the main manifestation of bronchial asthma is formed against the background of bronchial hyperreactivity, which appears in the presence of a genetic predisposition (or without it) under the influence of pollen, dust, epidermal and other allergens or irritants. Secondary spasm of the smooth muscles of the respiratory tract may be caused by the following pathological conditions:
- Allergic reactions. The body sometimes responds to the repeated introduction of an allergen by a sharp narrowing of the lumen of the airways. Oral administration or parenteral administration of drugs, vaccines and serums often leads to the appearance of such a reaction. Less often, bronchospasm occurs due to intolerance to certain foods, with insect bites.
- Infectious and inflammatory processes. They include acute and chronic bronchopulmonary diseases of bacterial (including tuberculosis) and viral nature. Bronchial obstruction syndrome complicates the course of COPD, chronic bronchitis and bronchiectatic disease, is detected in mycoses and helminthiasis of the lungs, diseases of the respiratory tract caused by protozoa.
- Hemodynamic disorders. Secondary narrowing of the bronchial lumen often accompanies circulatory disorders in the small circle. Symptoms of bronchospastic condition are present in pulmonary embolism, Aers syndrome, mitral valve stenosis and some other malformations.
- Bronchial obturation. Bronchospasm often becomes the first sign of obstruction of a section of the airway. It can be provoked by endobronchial tumor growth, aspiration of a foreign body, blockage of the organ lumen with viscous sputum in cystic fibrosis, compression of the bronchus from the outside with enlarged lymph nodes and formations.
- The effect of irritants and toxins. Inhalation of acid and alkaline compounds, insecticides and pesticides, thermal burns of the respiratory tract has an irritative effect on the bronchi. Perioperative bronchoconstriction develops as a result of mechanical irritation of the mucous membrane of the tracheobronchial tree during tracheal intubation. Toxic bronchospasm is caused by cholinomimetics, beta-blockers and some other drugs.
A number of patients have a bronchospastic condition of neurogenic genesis, formed with direct irritation of the vagus nerve, against the background of mental disorders and organic brain damage. Secondary bronchospasm is found in patients suffering from the pulmonary form of various autoimmune processes, with endocrine pathology and some rare diseases of the respiratory system.
Bronchospasm is the end result of a complex process regulated by the autonomic nervous system. It occurs with the predominance of the influence of the parasympathetic department responsible for the contraction of smooth muscle fibers of the bronchial wall. Under the influence of allergens, biologically active substances, toxins and irritants, with mechanical irritation of the vagal nerve, a large amount of acetylcholine is released – a mediator that excites the parasympathetic nervous system. At the same time, the synthesis of acetylcholinesterase, an acetylcholine–destroying enzyme, is inhibited, the receptors of the relaxing bronchial sympathoadrenal system are blocked.
Reversible thickening of the bronchial wall develops, swelling of the submucosal layer is detected. Bronchial glands hypertrophy, mucus production increases. The drainage and ventilation functions of the airways are disrupted. The rate of exhaled air flow decreases. Due to the violation of alveolar perfusion, hypoxia is formed, leading to increased work of the respiratory muscles. The participation of auxiliary muscles in the act of breathing increases the body’s oxygen consumption, which exacerbates hypoxia. In the absence of treatment, fatigue of the respiratory muscles may occur, which further reduces the effectiveness of ventilation, increases the content of carbon dioxide in the blood.
According to the etiology, bronchospasm is divided into primary, caused by hyperreactivity of the bronchi in bronchial asthma, and secondary, appearing in other pathologies. Secondary bronchospastic syndrome is classified by the immediate cause of occurrence and mechanism of development, can be reversible and irreversible, mild, moderate and severe. Depending on the prevalence of the process , the following types of bronchospasm are distinguished:
- Local. The smooth muscles of the bronchial walls are spasmed in a small area of the respiratory tract. The condition develops when a foreign object enters the bronchus, endobronchial growth of a neoplasm.
- Partial. The process is common, affects small and sometimes medium bronchi. Areas of normally ventilated alveolar tissue are preserved. The violation is more often found in respiratory pathology and hypersensitivity reactions. Leads to respiratory failure.
- Total. It is manifested by a sharp simultaneous spasm of smooth muscles of all large, medium and small bronchi. It is characteristic of the asthmatic status. Sometimes it is detected during surgery when the patient is put under anesthesia.
The clinical picture of the pathological condition largely depends on the etiopathogenesis and the prevalence of the process. In most cases, there is an unproductive paroxysmal cough. Sometimes, at the end of an attack, a meager amount of light mucous sputum is separated. The patient complains of sudden tightness in the chest, a feeling of lack of air and difficulty exhaling. The patient experiences a feeling of fear, cannot sleep. Sometimes shortness of breath is mixed, rarely inspiratory. The patient, and often the people around him, hear whistling wheezes.
Difficulty breathing increases in a horizontal position. In severe cases, the patient is forced to sit with his legs down, slightly leaning forward and leaning on his hands, or lie on his stomach with his head hanging down. Allergic bronchospasm is often accompanied by rhinorrhea, lacrimation, skin rashes like urticaria, swelling at the injection site or insect bite. Obstruction developing against the background of an infectious disease is accompanied by fever, general malaise, signs of the underlying pathology.
Hemodynamic bronchospasm is combined with chest pain, hemoptysis and cardiac arrhythmia. The nature of a cough attack caused by aspiration of a foreign object changes with a change in body position. With total bronchoconstriction, the patient’s condition is extremely severe. There is a loss of consciousness, the skin becomes cyanotic. Despite pronounced tachypnea (the frequency of respiratory movements reaches 60 per minute), respiratory noises are not heard. There is a sharp decrease in blood pressure, tachycardia.
Timely and adequate treatment allows you to completely and without consequences to stop bronchospasm. In mild cases, the patency of the bronchi is restored independently. The most formidable complication is the transformation of partial bronchoconstriction into total, observed with the aggravation of the asthmatic status. This condition annually leads to the death of more than 200 thousand people suffering from bronchial asthma. From 3 to 20% of deaths in a state of anesthesia during surgical interventions occur due to bronchospasm.
Primary diagnostic measures are usually carried out by emergency physicians and therapists of hospital emergency departments. In the future, the patient is examined by a pulmonologist, if necessary, allergologists, immunologists and other specialists can be involved in the diagnostic search. The main research methods that can detect bronchospasm are considered to be:
- Inspection. The examination evaluates the color of the skin. With severe bronchoconstriction, the skin turns pale, cyanosis of the lips and terminal phalanges of the fingers appears. Attention is drawn to the forced position of the patient’s body, the participation of auxiliary muscles in breathing. Distal hypertrophic osteoarthropathy is often observed in patients with bronchial obstruction against the background of chronic pulmonary pathology.
- Percussion, auscultation. Percussion determines the box sound over the entire surface of the lungs. During auscultation, hard breathing is heard, dry whistling wheezes on exhalation, less often wheezes are heard at the height of inspiration. There is tachypnea, palpitation of the heart. Severe life-threatening bronchospasm is characterized by the appearance of areas of the “silent lung”, in the projection of which respiratory noises are not carried out.
- Pulse oximetry. During the study, the pulse oximeter measures the saturation of arterial blood with oxygen and heart rate, specifies the degree of respiratory failure. Blood oxygenation of less than 95% along with tachycardia is a sign of oxygen starvation. Hypoxia is considered critical at saturation from 90% and below.
- Spirography. The study of the function of external respiration helps to differentiate obstructive disorders from restrictive ones. The presence of narrowing of the lumen of the respiratory tract is indicated by a decrease in the indicators of FEV1 and the Tiffno test. The use of a bronchodilation test makes it possible to identify the reversibility of bronchoconstriction.
- Radiography, CT of the lungs. They are auxiliary diagnostic methods. They are used to determine the cause of secondary airway obstruction. On radiographs and computed tomograms, emphysema of the lungs is visualized, X-ray contrast foreign bodies, tumors, enlarged lymph nodes, signs of other pathology of the respiratory tract are detected.
In order to diagnose bronchospastic conditions in young children, bronchophonography is used. An increase in the content of carbon dioxide in the exhaled air, determined by capnography, helps to detect bronchospasm in intubated patients. The most complete study of the function of external respiration can be done with the help of bodyplethysmography.
Treatment of bronchospastic condition is carried out by conservative methods. At the prehospital stage, inhalations of short-acting beta-adrenomimetics are used in the form of a dosed aerosol or through a nebulizer. You can use combinations of these drugs with cholinolytics or inhaled corticosteroids. If the therapy is not effective enough, the patient is provided with moistened oxygen through a nasal catheter, parenteral administration of methylxanthines and systemic corticosteroids is performed.
To stop an attack of suffocation on the background of anaphylaxis, epinephrine is the drug of choice, bronchodilators, corticosteroid hormones and antihistamines are additionally used. With total bronchospasm, emergency intubation and artificial ventilation of the lungs are indicated. Patients with prolonged attacks of suffocation are hospitalized in the department of therapy or pulmonology. Treatment of patients with asthmatic status is carried out in the ICU. At the hospital stage, the administration of bronchodilators and corticosteroids, oxygen therapy continues. If necessary, bronchoalveolar lavage, respiratory support is carried out.
Prognosis and prevention
The prognosis of the disease depends on the etiological factor that led to bronchoconstriction. Reversible attacks of suffocation respond well to medical treatment. Bronchospasm is very rarely the direct cause of death. In the case of secondary bronchoconstriction, death occurs more often from the underlying disease. For preventive purposes, contact with known allergens should be avoided, and recommendations for the treatment of the underlying pathology should be carefully followed.
- Letter: Bronchospasm, revealing, symptom of pulmonary embolism. Focan C, Bury J, Marcelle R. Nouv Presse Med. 1974 Jan 5;3(1):31. link
- Bronchospasm: an early manifestation of pulmonary embolism during and after anesthesia. Salem MR, Baraka A, Rattenborg CC, Holaday DA. Anesth Analg. 1968 Mar-Apr;47(2):103-7. link
- Bronchospasm disclosing pulmonary embolism. Perol M, Brun P, Arnouk H, Bayle JY, Guerin JC. Rev Pneumol Clin. 1990;46(5):225-8. link
- Impact-driven, pulmonary emboli of osseous fat in exercise-induced bronchospasm. Simkin PA, Snitily BK. Med Hypotheses. 2015 Nov;85(5):694-8. link
- Clinical and instrumental diagnosis of pulmonary embolism. Cina G, Pennestrí F. Rays. 1996 Jul-Sep;21(3):340-51. link