Introduction

Despite the great advances in medicine this century, pneumonia remains one of the leading causes of death in industrialised countries. It currently ranks fifth among overall causes of mortality and one of the first among infectious causes. Moreover, pneumonia is a major cause of respiratory failure in patients requiring intensive care unit admission and is one of the leading nosocomial infections in the critically ill. In this chapter we will highlight the major categories of pneumonia syndromes managed in the intensive care unit, their pathophysiological consequences, diagnostic work-up, antimicrobial therapy, ventilatory strategies, and recent advances in the care of these patients.

Community-acquired pneumonia

Recent studies continue to provide evidence that community-acquired pneumonia remains an important cause of morbidity and mortality accounting for 3% of all hospital admissions and a mortality rate ranging from 10–25%. Of those patients admitted to hospital with community-acquired pneumonia, 10–20% will require intensive care unit admission, among whom the mortality rate is high, ranging from 20–50% in most series. Although many of these patients who succumb from severe pneumonia have established underlying diseases, previously healthy people may also be susceptible. Factors associated with a poor prognosis include co-existent illnesses such as chronic obstructive lung disease, alcoholism, diabetes mellitus, the presence of shock, severe hypoxaemic respiratory failure, and inappropriate initial antibiotic therapy (Table 27.1). Severe community-acquired pneumonia can be defined as ‘life-threatening pneumonia acquired in a non immunosuppressed patient in the community who requires ICU admission’.