Severe pneumonia: Infectious Diseases Society of America and American Thoracic Society criteria

Major criteria
Respiratory distress requiring mechanical ventilation
Septic shock
Minor criteria
Respiratory rate > 30 breaths per minute
Blood urea nitrogen > 7 mmol/L
Leukopenia resulting from infection
Hypotension requiring aggressive fluids
PaO2 / FiO2 < 250
Multilobar infiltrates
Having at least 1 major criterion or at least 3 minor criteria suggests the need for intensive care.
  • From Mandell LA, Wunderink RG, Anzueto A, et al; Infectious Diseases Society of America; American Thoracic Society. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44(suppl 2):S27–S72, by permission of Oxford University Press.