Severe pneumonia: Infectious Diseases Society of America and American Thoracic Society criteria
| Major criteria |
| Respiratory distress requiring mechanical ventilation |
| Septic shock |
| Minor criteria |
| Confusion |
| Respiratory rate > 30 breaths per minute |
| Blood urea nitrogen > 7 mmol/L |
| Leukopenia resulting from infection |
| Thrombocytopenia |
| Hypothermia |
| 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.