Respiratory Health manual

Acute Exacerbation Chronic obstructive pulmonary disease (AECOPD) is one of the most common lung diseases. It is a progressive Chronic disease which is characterised by a decline in respiratory function and the worsening of symptoms provoke what are known as exacerbation.

The frequence of exacerbations has an impact on individual’s life expectancy. Moreover, they represent a significant cause of hospital admission and readmission. Acute exacerbations are an important cause of mortality and morbidity in patients with AECOPD.

AECOPD is the fourth leading cause of death and affects over 210 million people worldwide. In Europe, the prevalence in adult population has been estimated between 4-10 % . The development of AECOPD is not completely understood and may also depend on gender, genetic and socioeconomic factors (exposures to dusts, chemicals, pollutants).

The principal risks factor associated with AECOPD are :

• Smoking, (50 % of chronic smokers develop AECOPD).
• Air pollution and chemical fumes or dust from the environment.
• Genetics, in rare cases (deficiency of a protein which is called alpha-1 antitrypsin).

Two main forms of COPD exist : chronic bronchitis and emphysema :

• Chronic bronchitis is a cough with sputum production on most days during 3 months per year, for two consecutive years.
• Emphysema is an enlargement of the air spaces distal to the terminal bronchioles with destruction of their walls (which reduces the surface available for the exchange of oxygen and carbon dioxide).

Acute exacerbations of COPD (AECOPD) are commonly triggered by bacterial or viral pathogens and also pollutants. Typically, infections cause 75% or more of the exacerbations, bacteria alone can be found in roughly 25% of cases, viruses in another 25%, and viruses and bacteria coinfection in another 25%.

Furthermore, other factors may provoke exacerbations, such as environmental pollution (nitrogen dioxide)

Main pathogens involved in AECOPD
Viruses	Rhinovirus (66%), Influenza, Parainfluenza, Coronavirus Adenovirus, Respiratory Syncytial Virus, Picornavirus, Metapneumovirus.
Bacteria	Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus parainfluenzae, Pseudomonas aeruginosas.

The most common pathogens responsible for AECOPD