Table 1 Ventilator-associated pneumonia diagnostic algorithms utilized in this study
Published Criteria (citation) | Systemic Criteria | Chest Criteria | Chest Radiography Criteria | Microbiologic Criteria |
|---|---|---|---|---|
CDC/NHSN (25) | - Inflammatory response Temperature > 38 °C WBC > 12,000/mm3 or < 4,000/mm3 - OR new antimicrobial agent is started for ≥ 4 days  → Infection-related ventilator-associated complication | After a period of stability or improvement on the ventilator (≥ 2 calendar days of stable or ↓ FiO2 or PEEP): - Minimum daily FiO2 ↑ ≥ 0.20 lasting 2 days - Or minimum daily PEEP values ↑ ≥ 3 cm H2O lasting 2 days  → Ventilator-associated condition | – | Microbiologic quantitative ( +), OR histologic ( +), OR ( +) for legionella, influenza, RSV, adenovirus, or parainfluenza virus AND Gram-stain evidence ≥ 25 neutrophils/lpf and ≤ 10 epithelial cells/lpf  → Probable VAP |
CPISa (26) | Fever: - 38.5–38.9 (1 point) - ≥ 39 or < 36.5 (2 points) WBC: - < 4,000/mm3 or > 11,000/mm3 (2 points) | - Secretions but not purulent (1 point) - Purulent secretions (2 points) - PaO2/ FiO2 < 240 without ARDS (2 points) | Diffuse infiltrate (1 point) Localized infiltrate (2 points) Progressive infiltrate (without cardiac disease or ARDS) (+ 2) | Positive (1 point) |
HELICSb (27) | At least 1 criterion: - Temperature > 38 °C (with no other cause) - WBC > 12,000/mm3 or < 4,000/mm3 - If age > 70 years: AMS without other cause | At least 1 of following criteria (2 clinical pneumonia only = PN4 and PN5): New onset purulent sputum or change in sputum character (color, odor, quantity, consistency) Cough or dyspnea or tachypnea Suggestive auscultation (rales or bronchial breath sounds, rhonchi, wheezing) Worsening gas exchange (O2 desaturation, increasing FiO2 requirements or ventilation demands) | Image suggestive of pneumonia. (≥ 2 serial chest X-rays or CT scans with suggestive imaging for patients with underlying cardiac or pulmonary disease) | PN1 – ( +) quantitative Cx from minimally contaminated LRT specimen c PN2 – ( +) quantitative Cx from possibly contaminated LRT specimen d PN3 – Alternative methods: e ( +) blood or pleural Cx, pleural or pulmonary abscess, histology, or pathogen antigen or antibody testing PN4 – ( +) sputum Cx or non-quantitative LRT specimen Cx PN5 – No positive results |
Johanson (28) | Temperature > 38.5 °C WBC > 12,000/mm3 | Purulent secretions | New or progressive consolidation | – |