Ventilator-associated pneumonia and mortality: a true involvement or only an association?

Abstract

If ventilator-associated pneumonia (VAP) is known to increase morbidity, its exact role in intensive care unit (ICU) mortality remains debated. Mortality rates reported in numerous studies vary from 15 to 70%. This variability can be explained in several ways. First, since the gold standard to diagnose VAP, i.e. histological examination, is not applicable in routine practice, diagnosis remains difficult and heterogeneous in the different studies. Second, many events alter the prognosis of VAP, especially the appropriateness of empirical antibiotic therapy. Third, many associated pathologies add their own impact on mortality to that of VAP. The cause of death in the ICU is therefore difficult to determine with precision. Finally, statistical approaches to link VAP and mortality are numerous, but none is recognized as a gold standard. In conclusion, differentiating VAP-related mortality from mortality due to comorbidities remains a problem incompletely solved in critically ill patients.