What Is Acute Bronchitis?

Acute bronchitis is bronchial mucosal inflammation caused by infection with pathogens such as viruses or bacteria. It is a common and frequently-occurring disease in infants and young children, often secondary to upper respiratory infections, and often the early manifestation of pneumonia. The disease often affects both the trachea and bronchus, so the correct name should be acute tracheobronchitis. Clinically, it is characterized by cough with or without bronchial secretions.

Basic Information

Visiting department

Respiratory Medicine

Multiple groups

Infants

Common locations

bronchus

Common causes

Infections such as influenza viruses, inhalation of dust, smoke, pollen, etc.

Common symptoms

Cough with (or without) increased bronchial secretions

Causes of Acute Bronchitis

Infection

The viruses that cause the disease include adenovirus, influenza virus, respiratory syncytial virus, and parainfluenza virus; bacteria include Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus, and Staphylococcus. Viruses and bacteria can directly infect the trachea-bronchus, or they can invade the upper respiratory tract and cause the disease. In recent years, the number of mycoplasma and chlamydia causes has gradually increased.

2. Physical and chemical stimulation

Inhalation of cold air, dust, irritating gases or fumes (such as sulfur dioxide, nitrogen dioxide, ammonia, chlorine, ozone, etc.) can cause acute inflammation of the trachea-bronchial mucosa.

3. Allergies

Common allergens that cause tracheal and bronchial allergies include pollen, organic dust, bacterial proteins, fungal spores, and larvae of hookworms and roundworms that migrate in the lungs.

Clinical manifestations of acute bronchitis

Acute infectious bronchitis often precedes symptoms of acute upper respiratory infections: nasal congestion, discomfort, chills, low fever, back and muscle pain, and sore throat. The onset of a severe cough is usually a sign of bronchitis. At first, a dry cough without sputum, but a small amount of slimy sputum after a few hours or days, and more mucus or purulent sputum later. Obvious purulent sputum suggests multiple bacterial infections. Some patients have burning-like sternal pain that worsens when coughing. In severe cases without complications, fever of 38.3 to 38.8 ° C can last for 3 to 5 days. The acute symptoms subsequently disappeared (although the cough could continue for several weeks). Persistent fever is suggestive of pneumonia. Dyspnea secondary to airway obstruction can occur.

Acute bronchitis without complications has almost no signs of lungs. There may be scattered high-pitched or low-pitched dry rales, and occasionally whispered or wet rales at the bottom of the lungs. Especially after coughing, wheezing is often audible, and persistent chest signs suggest the occurrence of bronchial pneumonia. Therefore, some people think that acute bronchitis can be called "transient asthma" instead of "pulmonary infection".

Serious complications are usually seen only in patients with underlying chronic respiratory disease. Acute bronchitis in these patients can cause severe blood gas abnormalities (acute respiratory failure).

Acute bronchitis examination

Chest x-ray

The lung texture is thickened or normal, with occasional hilar shadows.

2. Blood biochemical examination

The total number of white blood cells in the surrounding blood is normal or low. The number of white blood cells increases when bacterial infection or bacterial infection occurs, and neutrophils increase.

Diagnosis of acute bronchitis

Diagnosis is usually based on symptoms and signs, but if the condition is severe or prolonged, there are indications for a chest X-ray to rule out other diseases or comorbidities. When severe underlying chronic respiratory disease is present, arterial blood gas analysis should be monitored. Patients who have failed antibiotic treatment or have special conditions (such as immunosuppression) should be sputum Gram stained and cultured to identify pathogenic bacteria.

Acute bronchitis treatment

The patient should rest until the temperature is normal. Patients should be encouraged to drink water during the fever. Antipyretic and analgesics (eg aspirin or acetaminophen for adults; acetaminophen for children) can relieve discomfort and lower body temperature.

Antibiotics should be used in patients with chronic obstructive pulmonary disease (COPD), purulent sputum or persistent high fever and severe illness. For most adult patients, oral tetracycline or ampicillin is the effective drug of choice, and TMP-SMX is an alternative treatment. Tetracycline is contraindicated in children under 8 years of age and can be given to amoxicillin. When symptoms persist or recur, or when the condition is abnormally severe, sputum smears and cultures should be performed. Then choose antibiotics based on the dominant pathogens and their drug sensitivity tests. If the pathogen is Mycoplasma pneumoniae or Chlamydia pneumoniae, erythromycin can be given.

During influenza virus A epidemics, treatment with amantadine hydrochloride may be considered.