MINOR CRITERIAARESPIRATORY RATEB _30 BREATHS/MINPAO2/FIO2 RATIOB _250MULTILOBAR INFILTRATESCONFUSION/DISORIENTATIONUREMIA (BUN LEVEL, _20 MG/DL)LEUKOPENIAC (WBC COUNT, !4000 CELLS/MM3)THROMBOCYTOPENIA (PLATELET COUNT, !100,000 CELLS/MM3)HYPOTHERMIA (CORE TEMPERATURE, !36_C)HYPOTENSION REQUIRING AGGRESSIVE FLUID RESUSCITATIONMAJOR CRITERIAINVASIVE MECHANICAL VENTILATIONSEPTIC SHOCK WITH THE NEED FOR VASOPRESSORS

Criteria for severe community-acquired pneumonia.

Most common etiologies of community-acquiredpneumonia.

Patient type EtiologyOutpatient Streptococcus pneumoniaeMycoplasma pneumoniaeHaemophilus influenzaeChlamydophila pneumoniaeRespiratory virusesaInpatient (non-ICU) S. pneumoniaeM. pneumoniaeC. pneumoniaeH. influenzaeLegionella speciesAspirationRespiratory virusesaInpatient (ICU) S. pneumoniaeStaphylococcus aureusLegionella speciesGram-negative bacilliH. influenzae

Recommended empirical antibiotics for community acquired pneumonia.

Outpatient treatment1. Previously healthy and no use of antimicrobials

within theprevious 3 monthsA macrolide (strong recommendation; level I

evidence)Doxycyline (weak recommendation; level III

evidence)

Epidemiologic conditions and/or risk factors related to specific pathogens in community-acquired pneumonia.

Condition Commonly encountered pathogen(s)Alcoholism Streptococcus pneumoniae, oral anaerobes,

Klebsiellapneumoniae, Acinetobacter species, MycobacteriumtuberculosisCOPD and/or smoking Haemophilus influenzae, Pseudomonas

aeruginosa,Legionella species, S. pneumoniae, Moraxella cararrhalis,Chlamydophila pneumoniaeAspiration Gram-negative enteric pathogens, oral anaerobesLung abscess CA-MRSA, oral anaerobes, endemic fungal

pneumonia,M. tuberculosis, atypical mycobacteria

Recommended empirical antibiotics for community acquired pneumonia.

2. Presence of comorbidities such as chronic heart, lung, liver

or renal disease; diabetes mellitus; alcoholism; malignancies;asplenia; immunosuppressing conditions or use ofimmunosuppressing drugs; or use of antimicrobials withinthe previous 3 months (in which case an alternative from adifferent class should be selected)A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, orlevofloxacin [750 mg]) (strong recommendation; level Ievidence)A b-lactam plus a macrolide (strong recommendation; level Ievidence) 

Recommended empirical antibiotics for community acquired pneumonia.

3. In regions with a high rate (125%) of infection with high-level(MIC _16 mg/mL) macrolide-resistant Streptococcus

pneumoniae,consider use of alternative agents listed above in(2) for patients without comorbidities (moderate

recommendation;level III evidence) 

Recommended empirical antibiotics for community acquired pneumonia.

Inpatients, non-ICU treatmentA respiratory fluoroquinolone (strong

recommendation; level Ievidence)A b-lactam plus a macrolide (strong

recommendation; level Ievidence)

RECOMMENDED EMPIRICAL ANTIBIOTICS FOR COMMUNITY ACQUIRED PNEUMONIA.

Inpatients, ICU treatmentA b-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam)plus either azithromycin (level II evidence) or a respiratoryfluoroquinolone (level I evidence) (strong recommendation)(for penicillin-allergic patients, a respiratory fluoroquinoloneand aztreonam are recommended) 

Recommended empirical antibiotics for community acquiredpneumonia.

Special concernsIf Pseudomonas is a considerationAn antipneumococcal, antipseudomonal b-lactam (piperacillintazobactam,cefepime, imipenem, or meropenem) pluseither ciprofloxacin or levofloxacin (750 mg)

orThe above b-lactam plus an aminoglycoside and azithromycin

orThe above b-lactam plus an aminoglycoside and an antipneumococcalfluoroquinolone (for penicillin-allergic patients,substitute aztreonam for above b-lactam)(moderate recommendation; level III evidence)If CA-MRSA is a consideration, add vancomycin or linezolid(moderate recommendation; level III evidence)  

Recommended empirical antibiotics for community acquiredpneumonia.

Exposure to bat or bird droppings Histoplasma capsulatumExposure to birds Chlamydophila psittaci (if poultry: avian

influenza)Exposure to rabbits Francisella tularensisExposure to farm animals or parturient cats Coxiella burnetti (Q

fever)HIV infection (early) S. pneumoniae, H. influenzae, M. tuberculosisHIV infection (late) The pathogens listed for early infection plus

Pneumocystisjirovecii, Cryptococcus, Histoplasma, Aspergillus,atypical mycobacteria (especially Mycobacteriumkansasii), P. aeruginosa, H. influenzae

Recommended empirical antibiotics for community acquiredpneumonia.

 

Hotel or cruise ship stay in previous 2 weeks Legionella speciesTravel to or residence in southwestern United States Coccidioides species,

HantavirusTravel to or residence in Southeast and East Asia Burkholderia pseudomallei,

avian influenza, SARS

Influenza active in community Influenza, S. pneumoniae, Staphylococcus aureus,

H. influenzaeCough 12 weeks with whoop or posttussivevomitingBordetella pertussisStructural lung disease (e.g., bronchiectasis) Pseudomonas aeruginosa,

Burkholderia cepacia, S. aureusInjection drug use S. aureus, anaerobes, M. tuberculosis, S. pneumoniaeEndobronchial obstruction Anaerobes, S. pneumoniae, H. influenzae, S. aureusIn context of bioterrorism Bacillus anthracis (anthrax), Yersinia pestis (plague),Francisella tularensis (tularemia)NOTE. CA-MRS