Clinical Features and Prognosisof Community-acquired Pneumonia in the Elderly Patients / 감염

ABSTRACT

BACKGROUND: Community-acquired pneumonia (CAP) is more frequent in the elderly and results in higher morbidity and mortality. Korea is undergoing extraordinary demographic change. Elderly patients constitute an even-increasing proportion of the population but there have been few studies on the epidemiological investigation of the CAP in the elderly. The purpose of this study was to characterize the background, etiology, clinical course and outcome of CAP in elderly compared with younger patients. METHODS: During the study period (from 1st January to 31th December 1997), 214 patients with CAP were reviewed with regard to epidemiological, clinical, laboratory and microbiological data. 119 elderly patients (> or =65 years-old of age) were compared with 95 younger patients (<65 years-old of age). The both groups were compared with each others in terms of variables related to CAP. RESULTS: Comparison of epidemiological data between older and younger patients revealed a high prevalence of alcoholics (40% vs 56%), current smoker (33% vs 56%), malignancy (8% vs 24%) in the elderly. In terms of complication and clinical manifestation, shock (1% vs 6%), intubation (6% vs 20%), mechanical ventilation apply (5% vs 18%), respiratory failure (2% vs 12%), dyspnea (26% vs 56%), altered consciousness (0% vs 13%), extrapulmonary symptom (11% vs 18%) and bilateral infiltration (8% vs 20%) showed higher incidence in the elderly than in the younger patients. Causative organisms are identified in 47% (56/119) of elderly patients those identified most frequently were S. pneumoniae (25%), K. pneumoniae (20%), S. aureus (16%), other Gram-negative bacilli (13%) and H. influenzae (11%). The overall mortality were significantly higher in the elderly patients (24%) than younger patients (5%). Two independent risk factors, those were related to the mortality of the elderlyhigher APACHE II score (RR3.43, 95% CI=1.43~7.21) and requirement of endotracheal tube (RR4.73; 95% CI=1.72~16.5). CONCLUSION: CAP in the elderly shows more serious clinical and abnormal laboratory features than younger patients. In elderly, S. pneumoniae was the most common causative organism for CAP but other agents, particularly K. pneumoniae was isolated frequently. The severity of illness at initial presentation such as high APACHE II score and requirement of endotracheal tube were the major variables affecting the outcome.