Hospital-acquired pneumonia and ventilator-associated pneumonia: recent advances in epidemiology and management

Abstract

Purpose of review: The recent evidence is reviewed on clinical epidemiology, trends in bacterial resistance, diagnostic tools and therapeutic options in hospital-acquired pneumonia (HAP), with a special focus on ventilator-associated pneumonia (VAP).

Recent findings: The current incidence of VAP ranges from two to 16 episodes for 1000 ventilator-days, with an attributable mortality of 3-17%. Staphylococcus aureus (with 50-80% of methicillin-resistant strains), Pseudomonas aeruginosa and Enterobacteriaceae represent the most frequent pathogens in HAP/VAP. The prevalence of carbapenemase-producing Gram-negative bacilli (GNB) and the emergence of colistin resistance are alarming. Procalcitonin seems to have a good value to monitor the response to treatment. Rapid molecular tests for the optimization of empirical therapy will be available soon. Recent studies support the use of a high-dosing regimen of colistin in HAP/VAP caused by extensively drug-resistant GNB. Linezolid may probably be preferred to vancomycin for a subset of methicillin-resistant S. aureus HAP/VAP. Given the scarcity of novel antimicrobial drugs, different approaches such as bacteriophage therapy or immunotherapy warrant further clinical evaluations.

Summary: HAP/VAP is a major cause of deaths, morbidity and resources utilization, notably in patients with severe underlying conditions. The development of new diagnostic tools and therapeutic weapons is urgently needed to face the epidemic of multidrug-resistant pathogens.