Infective Exacerbation of Bronchiectasis - An Overview

Introduction

Lungs are vital organs of respiration and are subdivided into lung parenchyma and bronchi. Lung parenchyma is responsible for the exchange of gasses, and bronchi are large tubes that extend from the trachea (windpipe). During breathing, oxygen travels to the lungs through the airways, also known as bronchi. These airways end up in tiny sacs called alveoli, from which oxygen is absorbed into the bloodstream. A sticky mucus layer lines the inside walls of the bronchi and protects the lungs against damage. When the airways widen, excess mucus accumulates, increasing the lungs' susceptibility to infections. Bronchiectasis can cause significant loss of lung function and requires an interprofessional team effort to reduce the symptoms and prevent relapses.

What Is Bronchiectasis?

Bronchiectasis is a lung disease characterized by the widening of the bronchial airways, which results in excess mucus accumulation and makes the lungs vulnerable to infections. It is a chronic condition associated with persistent coughing and shortness of breath. It can affect one or both lungs, and symptoms can worsen during infections, leading to lung damage. Bronchiectasis is uncommon; however, global statistics have reported an increase in the incidence of bronchiectasis over the past few years. The most common causes of bronchiectasis include immune system abnormalities and infections such as pneumonia (lung infection), tuberculosis (a bacterial infection that mainly affects the lungs), or whooping cough. However, there may not be a specific cause for this condition in most cases. Currently, no permanent cure for bronchiectasis exists, but it can be managed by medications, breathing exercises, and lowering the chance of infections, improving the quality of life.

What Are the Causes of Exacerbation of Bronchiectasis?

An exacerbation or worsening of the symptoms of bronchiectasis is also known as a flare-up. These are significant adverse events in the natural course of the condition and determine long-term clinical outcomes. Bronchiectasis is a heterogeneous condition, and many patients frequently experience acute worsening of symptoms, which can be challenging to manage and a considerable healthcare burden. The exact cause of bronchiectasis is poorly understood due to the lack of mechanistic studies; however, several factors, including inflammation, microorganisms, and external environmental factors, can increase the risk of exacerbation.

Bacterial infection is typically considered the most probable cause of bronchiectasis exacerbation. It is confirmed by certain observational studies that have demonstrated a clear association between chronic bacterial infections and the risk of exacerbation. Also, antibiotic therapy reduces airway bacteria and markers of airway and systemic inflammation in such patients, leading to significant clinical improvements. A multicenter study in the United States included 830 bronchiectasis patients who reported Staphylococcus aureus infection in 94 patients. Patients with Staphylococcus aureus infection exhibited a higher exacerbation rate than those without prior Gram-negative bacilli or S. aureus growth in the sputum samples. Viral infections are also likely responsible for a major proportion of exacerbations, as it is supported by both direct and indirect evidence. Influenza virus, rhinovirus, and seasonal coronaviruses were the most commonly found viruses in patients with bronchiectasis exacerbations. Respiratory viruses were reported in approximately 25 percent of patients experiencing exacerbations of the condition. A combination of viruses and bacteria or patients with microbial colonization in their lungs, especially Pseudomonas species, are more prone to experiencing bronchiectasis exacerbations.

Patients with a history of exacerbations, comorbid airway diseases such as asthma (swelling or narrowing of the airways) or chronic obstructive pulmonary disease (COPD), immunodeficiency, allergic bronchopulmonary aspergillosis (fungal infection), and external factors such as an increase in pollen count, worsening air pollution, dust, smoking, a change in weather, and missing regular bronchiectasis medications or breathing exercises are a few other causes of exacerbations.

What Are the Symptoms of Infective Exacerbation of Bronchiectasis?

Symptoms of bronchiectasis usually tend to worsen during a flare-up, or patients may also experience certain new symptoms. Clinically, exacerbation of bronchiectasis was initially recognized as deterioration of respiratory symptoms, which requires medical help or antibiotic treatment. However, it was observed that patients may have different thresholds for reporting deterioration of symptoms, and it was also challenging during clinical trials when exacerbations were a primary endpoint. Therefore, a uniform definition was generated in 2017, according to which an individual with a deterioration of three or more key symptoms for about 48 hours and the clinician’s decision to change the bronchiectasis treatment is necessary.

These key symptoms are:

• Cough.

• Sputum volume and consistency.

• Sputum purulence.

• Breathlessness and or exercise intolerance.

• Hemoptysis.

• Fatigue or tiredness.

• Fever, chest pain, and wheezing may be associated symptoms.

How Is Infective Exacerbation of Bronchiectasis Diagnosed?

The exacerbation of bronchiectasis is diagnosed by symptoms described by the patient or caregivers and a chest examination. Some of the tests recommended to confirm the diagnosis include:

• Blood tests are performed to check for infection, determine the microorganism, and whether other medical conditions may contribute to exacerbation.

• Sputum samples are collected and sent for examination to identify the pathogen, facilitating treatment planning.

• Chest X-ray is suggested if pneumonia is suspected or to check for fluid accumulation or collapsed lungs.

• An electrocardiogram test may also be performed to check the condition of the heart or rule out cardiovascular abnormalities.

What Is the Treatment for Infective Exacerbation of Bronchiectasis?

The International Bronchiectasis Guidelines have recommended antibiotics as the mainstay treatment for exacerbations of bronchiectasis. Antibiotics are selected based on the sputum culture test reports or, if unavailable, based on the local data to evaluate common pathogens that may be found in bronchiectasis patients.

Antibiotics reduce the bacterial load and systemic inflammation, lowering symptoms and improving the patient’s condition. Healthcare experts usually recommend a 14 days antibiotic course, especially for patients with Pseudomonas aeruginosa infections; however, short courses may be sufficient for mild exacerbations. Intravenous antibiotics are prescribed for patients who are unable to take medications orally.

Other management strategies include chest physiotherapy, nebulization, oxygen therapy, breathing techniques, and mucolytic medications to clear the mucus. Studies have shown that the airway clearance technique (ACT) is safe for adult patients and can be used to manage acute exacerbations, and pulmonary rehabilitation performed after antibiotic therapy can be beneficial.

How Can Exacerbations of Bronchiectasis Be Prevented?

• Studies have shown that regular airway clearance can reduce bronchiectasis exacerbations; hence, patients must be encouraged to practice these techniques. It is mainly indicated in patients with copious phlegm, which is difficult to expectorate. However, each session must be personalized and guided by an expert physiotherapist, depending on the patient’s condition and characteristics.

• Inhaled antibiotics can be used in frequent exacerbations to eradicate or suppress Pseudomonas aeruginosa organisms. This not only reduces the frequency but also helps reduce the severity.

• Long-term macrolide therapy is recommended for patients with frequent bronchiectasis exacerbations but without chronic P. aeruginosa infection. It reduces airway inflammation and helps to defend against infections more effectively.

• Inhaled corticosteroids (ICS) are commonly used as anti-inflammatory agents; however, it is not recommended for the overall bronchiectasis population but only for patients with asthma or allergic bronchopulmonary aspergillosis and are prone to experiencing bronchiectasis exacerbations.

Conclusion

Bronchiectasis is a debilitating lung disease that requires persistent management to reduce symptoms and prevent exacerbations. Regular monitoring, appropriate antibiotics, and physiotherapy can provide comprehensive care. However, a personalized interprofessional approach is necessary to optimize better clinical outcomes. Although no permanent cure exists for this condition, understanding the causes and implementing effective treatment strategies can significantly enhance the patient’s quality of life.