Chronic obstructive pulmonary disease is common and is associated with high morbidity and mortality. It leads to huge costs in the health care system. One of the resons is acute exacerbations that lead to hospital admissions, increased medication use and other costly operations. They can also lead to death. In this review we will discuss the definition of acute exacerbation, causes and differential diagnosis. Treatment will be discussed and ways to avoid repeated exacerbations. Among ways to prevent acute exacerbations is drug treatment such as inhaled long-acting bronchodilators, inhaled corticosteroids and combination treatment. In selected cases antibiotics and antioxidants can be helpful. Influenza and pneumococcal vaccinations are important in addition to pulmonary rehabiliation. It is important to evaluate the role of co-morbidities and treat those diseases also. Examples of comorbidites are coronary artery disease and heart failure but also anxiety and depression.

Picture 1. Effects of acute exacerbations on patients with chronic obstructive pulmonary disease.

Tables:

Table 1. Risk factors for acute exacerbations

Increasing age	Longer duration of COPD
Severity of obstruction	Colonization of airways
Prior history of inhaled COPD drug use	Comorbidites
Chronic bronchial mucus production	Poor health related quality of life
Productive cough and wheezing	Prior history of exacerbations
Antibiotic or systemic steroid use

Table 2. Selected comorbidities of COPD

Cardiovascular diseases	Depression
Heart failure	Anxiety
Pulmonary hypertension	Gastroesophageal reflux
Pulmonary embolism	Diabetes mellitus
Osteoporosis	Sleep disturbances

Table 3. Causes of infection in AECOPD

Bakteria	Tíðni
Hemofilus influenzae	20-30%
Streptokokkus pneumoniae	10-15%
Moraxella cataralis	10-15%
Pseudomonas aeruginosa	5-10%
Viruses
Rhinovirus	10-25%
Parainfluensavirus	5-10%
Influensuvirus	5-10%
Respiratory syncytial virus	5-10%

Table 4. Treatments that can prevent acute exacerbations of chronic obstructive pulmonary disease

Pharmacological	Nonpharmacological
Long acting bronchodilators	Tobacco cessation
Inhaled corticosteroids	Influenza vaccination
Antioxidants	Pnumococcal vaccination
Antibiotics	Pulmonary rehabilitation
Betablockers if indicated for comorbidities	Nutritional assessment