ICU-acquired pneumonia beyond pathogen detection

Intensive care unit-acquired pneumonia is often treated as a binary diagnosis, although clinical deterioration, imaging and microbial detection describe different aspects of disease. This Perspective proposes an explicit, graded and revisable assessment of whether a detected organism plausibly causes the current lung injury. The framework encompasses pneumonia arising during ventilation, pneumonia that precedes intubation and pneumonia in non-ventilated ICU patients. It places molecular results within clinical, anatomical, microbiological and host context and uses formal reassessment at 48-72 hours to guide treatment continuation, narrowing or discontinuation.