The Clinical Pulmonary Infection Score (CPIS) is a bedside scoring system designed to estimate the likelihood of ventilator-associated pneumonia (VAP) by combining several clinical, laboratory, physiologic, radiographic, and (optionally) microbiology findings into a single number. It was originally developed to bring more structure to VAP assessment, since individual signs like fever or purulent secretions aren’t reliable enough on their own.

What CPIS includes

Classic CPIS assigns 0–2 points across commonly used domains (total typically 0–12):

• Temperature
• White blood cell count (with band forms in some versions)
• Tracheal secretions (amount/character; purulence increases score)
• Oxygenation via PaO₂/FiO₂ (worse oxygenation can increase score, except when explained by ARDS in some schemes)
• Chest radiograph infiltrates (none vs diffuse vs localized)
• Culture/Gram stain of tracheal aspirate (optional component in some workflows)

How it’s interpreted (and an important caution)

A commonly used threshold is CPIS > 6 (often written as ≥6) as “suggestive” of VAP.
However, major guidelines caution that CPIS does not have high enough diagnostic accuracy to be used as the sole basis for starting/stopping antibiotics; clinical judgment and diagnostic testing remain essential.