Antibiotics can be effective against acute exacerbations of chronic bronchi
tis and chronic obstructive pulmonary disease, but with bacterial resistanc
e to multiple antibiotics increasing worldwide, appropriate antibiotic sele
ction is critical. Categorizing patients with acute exacerbations according
to age, number of exacerbations per year, disease severity, degree of pulm
onary impairment, and presence of comorbid conditions helps to direct thera
py.