Pneumonia in the elderly (geriatric) population

Abstract

Review of recent studies (2003 and 2004) concerning pneumonia in the very old. Hospitalisation for community-acquired pneumonia (CAP) in the elderly is associated with a high mortality and with a high rate of readmission within the following year. Functional status, altered mental status, number of comorbidities, aspiration pneumonia, renal failure, and nutritional status are all indicators of adverse prognosis. Although Streptococcus pneumoniae, Haemophilus influenzae, Enterobacteriacae, and Staphylococcus aureus are the most frequently identified causative microorganisms, viruses account for up to 26% of hospital admissions for CAP. Chlamydia pneumoniae is also implicated in CAP and in nursing-home-acquired pneumonia (NHAP), with recent reports of outbreaks in nursing homes. Aspiration pneumonia is frequent in the elderly and occurs with increased frequency in patients with nasogastric tubes or percutaneous enterogastric tubes. In severe aspiration pneumonia, 20% of organisms implicated are anaerobic and 80% aerobic, most of which are gram-negative Enterobacteriaceae. Poor oral hygiene increases subsequent risk of pneumonia: dental plaque may act as a reservoir for pathogenic organisms implicated in CAP or NHAP. Prevention of CAP and NHAP relies on the combined use of influenza and pneumococcal vaccination, which decreases hospital admissions and in-hospital mortality for CAP. Recent studies stress the importance of aspiration as a frequent mechanism of CAP, provide new insights as to causative organisms in this setting, and underline the contribution of combined vaccination in reducing morbidity and mortality.