Purpose of review
Hospital-acquired pneumonia (HAP) is a form of nosocomial pneumonia, distinct from ventilator-associated pneumonia (VAP). This review compares HAP and VAP, highlighting differences in natural history, risk factors, and bacteriology that necessitate a different approach to the therapy of HAP, compared with VAP.
HAP can arise out of the ICU, or in the ICU, and can lead to severe illness, including the need for intubation and mechanical ventilation. New American and European nosocomial pneumonia guidelines make therapy recommendations for HAP. The American guidelines recommend broader spectrum therapy than the European guidelines, but recent studies support the idea that not all HAP patients need antipseudomonal therapy. When the American guideline approach to HAP has been studied, it led to both overtreatment and inappropriate therapy for the identified pathogens. An algorithm, modified from the European guideline, proposes an approach to therapy that necessitates dual antipseudomonal therapy in less than 25% of all HAP patients.
Although more prospective therapy trials of HAP are needed, based on currently available data, it is possible to use an approach that provides appropriate therapy without the overuse of broad-spectrum therapy.