Professor Zhou Yuqi Bio

Doctor of Medicine, Doctoral Supervisor, Chief Physician Director of the Department of Respiratory and Critical Care Medicine of the Third Affiliated Hospital of Sun Yat-sen University, Deputy Director of the Internal Medicine Department of the Third Affiliated Hospital of Sun Yat-sen University, Core Physician of the Department of Allergic Disease (Allergy) of the Third Affiliated Hospital of Sun Yat-sen University, Director of Guangdong Research Centre of Chronic Obstructive Pulmonary Disease Rehabilitation Engineering Technology, Chairman of the Expert Committee on Allergic Disease of Guangdong Pharmaceutical Association, Member of the Geriatric Respiratory and Critical Care Medicine Branch of the China Association of Gerontology and Geriatrics, Vice Chairman of the Respiratory Disease Specialised Committee of Guangdong Association of Integrated Traditional and Western Medicine, Vice-chairman of the Non-Tuberculosis Mycobacterial Disease Specialised Committee of Antituberculosis Association of Guangdong, Member of the COPD Group of the Respiratory Disease Branch of Guangdong Medical Association, Member of the Rare Disease Branch of Guangdong Medical Association, Member of the Respiratory Therapy Group of the Respiratory Physicians Branch of Guangdong Medical Doctor Association, Member of the Standing Committee of the Swallowing Disorder Rehabilitation Branch of the Guangdong Association of Rehabilitation Medicine. Presided over and participated in numerous provincial-level research projects, published more than 20 SCI papers, edited two monographs, and obtained more than 10 utility model patents. Specialises in the prevention and treatment of COPD, respiratory infection disease, chronic cough, and bronchial asthma.

Introduction: Updates to the 2023 Chinese Expert Consensus on AECOPD: Increased objectivity, enhanced directness, greater practicality, and alignment with clinical practice!

Dating back to 2018, the “Chinese Pulmonary Health Study” revealed that the prevalence of chronic obstructive pulmonary disease (COPD) among individuals aged 40 years and older in China had surged to 13.7%, and the estimated total number of patients with COPD nationwide had reached approximately 100 million people¹. As a chronic respiratory disease with a high outpatient emergency department visit rate in China’s internal medicine departments, patients with COPD experience an average of 0.5–3.5 acute exacerbations annually, which has become the leading cause of mortality among these patients².

This year, the “Chinese Expert Consensus on the Diagnosis and Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) (2023 Revision)” (referred to as “the consensus” hereafter) was released. This revision included updates to the definition, severity grading, and recommendations for empirical antibiotic use for AECOPD ². Media from the “Medical Profession” had the privilege of inviting Professor Zhou Yuqi from the Department of Respiratory and Critical Care Medicine at the Third Affiliated Hospital of Sun Yat-sen University to have an in-depth discussion regarding the updates to the consensus in the context of clinical practice.

The definition of AECOPD is now more complete and precise ─ from the time of onset to the underlying mechanisms of the disease
The consensus has refined its definition of AECOPD by incorporating insights from the “Rome Proposal” and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2023 Guidelines. Specifically, it clarifies that AECOPD refers to exacerbated symptoms of dyspnoea and/or worsening of cough and sputum, with worsening of symptoms occurring within 14 days, and may be accompanied by tachypnoea and/or tachycardia. This revision renders the definition of AECOPD more objective and credible, making it easier for clinicians to understand the disease.

“In the past, there was a lack of clinical consensus regarding the timeline of COPD progression. The new definition provides us with a better framework for evaluating certain ambiguous situations. For symptoms that appear over a short period of time, we can ascertain their classification as AECOPD based on specific circumstances; if the symptoms persist for an extended duration, they may not be classified as AECOPD.

In addition to inflammation, various factors such as vascular changes, allergic reactions, and environmental pollution can lead to acute exacerbations of COPD. As clinicians, we should adopt a more comprehensive and complete consideration of factors contributing to AECOPD. Clinical diagnosis and treatment should not be limited to targeting a single causative factor.” says Professor Zhou Yuqi.

Viruses, bacteria, environmental pollutants, or other stimuli can all trigger the activation of a large number of inflammatory cells within the respiratory tract, releasing multiple inflammatory mediators. During such instances, hypersecretion of airway mucus leads to increased airway resistance, airway stenosis, and exacerbated airflow limitation. Restricted airflow further leads to lung hyperinflation and gas trapping. The increased respiratory load leads to respiratory muscle fatigue and a weakened respiratory drive, which further decreases alveolar ventilation significantly and worsens the patient’s condition. Only targeted treatment can improve clinical outcomes for these patients. This consensus update effectively assists clinicians, especially those working in secondary hospitals or primary care units, to gain a better grasp of the clinical diagnosis and treatment of AECOPD.

Choosing a treatment regimen starts with identifying the triggers of AECOPD
Notably, 78% of patients with AECOPD exhibit clear evidence of viral or bacterial infections, which are the most common triggers of AECOPD. Among them, almost 50% of AECOPD cases feature upper respiratory tract viral co-infections, with the most common viruses being rhinovirus, respiratory syncytial virus, and influenza virus². In terms of bacterial infections, the most common pathogens are Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae. In addition, atypical pathogens such as Chlamydia pneumoniae are also major AECOPD pathogens. Professor Zhou Yuqi highlighted that some patients may also have fungal infections. Furthermore, environmental factors such as smoking and air pollution, as well as other factors, can lead to AECOPD.

Distinct targeted treatment regimens should be implemented in clinical practice for AECOPD. For example, AECOPD in some patients may be caused by pneumothorax, necessitating pneumothorax-related treatments. Similarly, patients with symptoms such as allergic rhinitis and hives should be treated accordingly for their symptoms and allergens. In some patients, AECOPD may be the result of a combination of triggers, which are generally more severe cases that may require longer treatment durations.

The determination of triggers and treatment options during acute exacerbations serves as an important guide for selecting prophylactic treatment options during the stable phase. For patients who are prone to infections or whose AECOPD is caused by infections, vaccines can be administered during the stable period to enhance their immunity. For patients whose AECOPD is caused by anaphylaxis, conscious avoidance of contact with allergens during the stable period or use of specific steroids for treatment is necessary. It is also necessary to have targeted prevention and control measures for AECOPD in patients who are affected by other triggers.

At present, some patients with COPD use long-term glucocorticoids. Attention to infection prevention and control is required for these patients. Patients with COPD often suffer from dyspnoea, reflux, and other issues. In cases where the patient has fungal or oral bacterial infections, pathogens can easily enter the lower respiratory tract through reflux. Under such circumstances, using glucocorticoids could potentially exacerbate the infection.

Bacterial infection is a major trigger of AECOPD, necessitating tailored anti-infective treatment regimens in accordance with the characteristics of the pathogen
In clinical practice, the antimicrobial therapy for AECOPD caused by infections is usually managed with reference to the treatment of community-acquired infectious diseases. Microorganisms isolated from patients with AECOPD are also common causes of community-acquired infectious diseases observed in clinical practice. According to statistics, bacteria can be isolated from sputum in 40–60% of patients with AECOPD. Among these cases, the three most common pathogens are Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Pseudomonas aeruginosa, gram-negative Enterobacteriaceae, Staphylococcus aureus, and Haemophilus parainfluenzae.

Oral antimicrobial therapy may be administered to the patient if significant exudative pulmonary effusion is not observed on computed tomography (CT) or X-ray, and the patient is not severely ill or suffering from multiple comorbidities. Initial antimicrobial therapy should focus on improving both short-term patient outcomes and minimising the risk of future acute exacerbations in patients with COPD by reducing the frequency of AECOPD exacerbations, extending the interval between exacerbations, and minimising the bacterial load within the lower respiratory tract.

In terms of antimicrobial drug selection, respiratory quinolones can effectively achieve therapeutic goals in AECOPD. The common causative pathogens of AECOPD are sensitive to respiratory quinolones. These drugs also cover atypical pathogens and can improve a patient’s infection condition with once-a-day dosing. Serving as the “new star” of respiratory quinolones, sitafloxacin provides new clinical options for respiratory quinolone therapy. The new-generation respiratory quinolone sitafloxacin offers broad-spectrum coverage of common gram-positive bacteria, gram-negative bacteria, anaerobic bacteria, and atypical respiratory tract pathogens. Sitafloxacin exhibits high sensitivity to drug-resistant organisms such as Pseudomonas aeruginosa and MRSA, and can serve as a treatment option for AECOPD.

Conclusion
The 2023 edition of the consensus has updated the definition of AECOPD, severity grading, and recommendations for empirical selection of antimicrobials. It acknowledges that viral infections, bacterial infections, environmental pollutants and other stimuli can all trigger AECOPD. In terms of bacterial infections, the most common pathogens are Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae. Treatment of AECOPD caused by bacterial infections is usually managed with reference to community-acquired infectious diseases. As a broad-spectrum antimicrobial agent covering common gram-positive, gram-negative, anaerobic, and atypical pathogens of the respiratory tract, the new-generation respiratory quinolone sitafloxacin provides a new option for anti-infective therapy in AECOPD.

References

1. Li, H., Li, P., Zeng, Q., et. al. Summary of Best Evidence of Rehabilitation Education in Pulmonary Patients with Chronic Obstructive Pulmonary Disease. Journal of Nursing Science, 2022, 37(03):79-83.

2. Expert Group on Diagnosis and Management of Acute Exacerbations of Chronic Obstructive Pulmonary Disease. Chinese Expert Consensus on the Diagnosis and Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease (2023 revised edition). International Journal of Respiration, 2023, 43(2) : 132-149. DOI: 10.3760/cma.j.cn131368-20221123-01066.

3. Mikasa, K., Aoki, N., Aoki, Y., Abe, S., & Yoshida, K. (2014). [The JAID/JSC Guideline to Clinical Management of Infectious Diseases (Respiratory Infections)] Kansenshogaku Zasshi, 88(1), 1-109.