Is ventilated hospital-acquired pneumonia a worse entity than ventilator-associated pneumonia?

INTRODUCTION: Nosocomial pneumonia develops after ≥48 h of hospitalisation and is classified as ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP); the latter may require mechanical ventilation (V-HAP) or not (NV-HAP). MAIN FINDINGS: VAP and HAP affect a significant proportion of hospitalised patients and are characterised by poor clinical outcomes. Among them, V-HAP has the greatest 28-day mortality rate followed by VAP and NV-HAP (27.8% versus 18% versus 14.5%, respectively). However, no differences in terms of pathophysiology, underlying microbiological pathways and subsequent therapy have been identified. International guidelines suggest specific flow charts to help clinicians in the therapeutic management of such diseases; however, there are no specific recommendations beyond VAP and HAP classification. HAP subtypes are scarcely considered as different entities and the lack of data from the clinical scenario limits any final conclusion. Hopefully, recent understanding of the pathophysiology of such diseases, as well as the discovery of new therapies, will improve the outcome associated with such pulmonary infections. CONCLUSION: Nosocomial pneumonia is a multifaced disease with features of pivotal interest in critical care medicine. Due to the worrisome data on mortality of patients with nosocomial pneumonia, further prospective studies focused on this topic are urgently needed.