Pneumonia in the ICU

Community-acquired and nosocomial pneumonia occur frequently within their defined populations. Community-acquired pneumonia presents a spectrum of severity from mild to rapidly fatal disease. The CURB-65 score is used to define severity together with co-morbid conditions and other criteria. In those patients identified as suffering from severe disease a multisystem approach must be used, focusing on resuscitation and organ-system support as well as antibiotic therapy. Most fatalities are the result of complications of multiorgan failure, hence the requirement for invasive circulatory monitoring together with varying degrees of ventilatory, cardiovascular and other organ system support. Nosocomial pneumonia particularly affects patients requiring endotracheal intubation for provision of mechanical ventilatory support. Nosocomial pneumonia may occur early or late in the patient’s clinical course, with different causative organisms necessitating different treatment strategies. Many risk factors and preventative measures have been recognized for ventilator-associated pneumonia and only late-onset disease is associated with an excess mortality. Many diagnostic techniques can be applied to the management of ventilator-associated pneumonia. Initial treatment with antimicrobial agents is usually empirical and should reflect local experience and guidelines. Pneumonia also frequently affects immunocompromised patients, where the causative pathogens are very different, the commonest being Pneumocystis jirovecii for which specific antimicrobial treatment is required.