Adults
In 2001 the American Thoracic Society, drawing on the work of the British and Canadian Thoracic Societies, established guidelines for the management of adult CAP by dividing patients into four categories based on common organisms:
Healthy outpatients without risk factors: This group (the largest) is composed of otherwise-healthy patients without risk factors for DRSP, enteric gram-negative bacteria, pseudomonas or other, less common, causes of CAP. Primary microorganisms are viruses, atypical bacteria, penicillin-sensitive streptococcus pneumoniae and haemophilus influenzae. Recommended drugs are macrolide antibiotics, such as azithromycin or clarithromycin, for seven to ten days. A shorter course of these antibiotics has been investigated, however, there is not sufficient evidence to make recommendations. Outpatients with underlying illness or risk factors: Although this group does not require hospitalization, they have underlying health problems such as emphysema or heart failure or are at risk for DRSP or enteric gram-negative bacteria. They may be treated with a quinolone active against streptococcus pneumoniae (such as levofloxacin) or a β-lactam antibiotic (such as cefpodoxime, cefuroxime, amoxicillin or amoxicillin/clavulanic acid) and a macrolide antibiotic, such as azithromycin or clarithromycin, for seven to ten days. Hospitalized patients without risk for pseudomonas: This group requires intravenous antibiotics, with a quinolone active against streptococcus pneumoniae (such as levofloxacin), a β-lactam antibiotic (such as cefotaxime, ceftriaxone, ampicillin/sulbactam or high-dose ampicillin plus a macrolide antibiotic (such as azithromycin or clarithromycin) for seven to ten days. Intensive-care patients at risk for pseudomonas aeruginosa: These patients require antibiotics targeting this difficult-to-eradicate bacterium.
All patients with CAP should have their blood oxygen monitored with pulse oximetry. In some cases, arterial blood gas analysis may be required to determine the amount of oxygen in the blood. A complete blood count (CBC) may reveal extra white blood cells, indicating infection. Prevention
CAP may be prevented by treating underlying illnesses that increasing its risk, by smoking cessation, and by vaccination. Vaccination against haemophilus influenzae and streptococcus pneumoniae in the first year of life has been protective against childhood CAP. A vaccine against streptococcus pneumoniae, available for adults, is recommended for healthy individuals over 65 and all adults with COPD, heart failure, diabetes mellitus, cirrhosis, alcoholism, cerebrospinal fluid leaks or who have had a splenectomy. Re-vaccination may be required after five or ten years.Patients who have been vaccinated against streptococcus pneumoniae, health professionals, nursing-home residents and pregnant women should be vaccinated annually against influenza. During an outbreak, drugs such as amantadine, rimantadine, zanamivir and oseltamivir have been demonstrated to prevent influenza. Treatment
CAP is treated with an antibiotic that kills the infecting microorganism; treatment also aims at managing complications. If the causative microorganism is unidentified, which is often the case, the laboratory identifies the most effective antibiotic; this may take several days. Health professionals consider a persons risk factors for various organisms when choosing an initial antibiotic. Additional consideration is given to the treatment setting; most patients are cured by oral medication, while others must be hospitalized for intravenous therapy or intensive care.