Incidence, microbiology, and mortality of ventilation-associated pneumonia in a large Italian cohort of critically ill patients: results from the PROSAFE project.

Objectives: Despite preventive measures, ventilator-associated pneumonia (VAP) remains the most common healthcare-associated infection in the intensive care unit (ICU). VAP's striking incidence and impact are a leading cause of morbidity and prolonged ICU stay. This study focused on the characteristics and outcomes of patients diagnosed with ICU-acquired VAPs in Italian ICUs.

Methods: Data were drawn from the PROSAFE network, a prospective multicentric observational project conducted across 192 Italian ICUs (2014-2023). Clinical data were recorded following the European Centre for Disease Prevention and Control VAP definitions. The incidence rate was estimated, and multivariable logistic regression identified ICU mortality risk factors.

Results: The patients admitted to the included ICUs were 402 085. Among 122 430 classified at risk for VAP because of invasive mechanical ventilation (IMV) ≥48 hours, a total of 11 978 VAP cases were identified, corresponding to a prevalence of 9.8%. The incidence rate of VAP was 10.47 cases per 1 000 ventilator days (95% CI: 10.28-10.66). Patients with VAP exhibited prolonged ICU stays (median: 23 days, Q1-Q3: 15-36) and high mortality (30.0%). Microbiological profiling of VAP identified Pseudomonas spp. (21.0%), Staphylococcus aureus (20.2%), and Klebsiella spp. (20.1%) as the predominant pathogens. The logistic regression showed that older age, chronic liver and kidney diseases, multidrug-resistant organisms, and Acinetobacter spp. aetiology and duration of ICU stay before VAP were significantly associated with higher mortality.

Discussion: While confirming the overall high mortality of patients undergoing IMV, our findings highlight the significantly prolonged ICU stay in VAP patients, and the influence of multidrug-resistant organisms on VAP-related mortality. These insights emphasize the necessity for effective and timely preventive strategies, as well as the early identification of VAP aetiology.