[The clinical feature of febrile episodes]

Institutionalized elderly patients are at risk of nosocomial infection because of their compromised status by aging. To clarify the relationship between fever and disease in elderly patients, we analyzed 1,105 febrile episodes, the etiology of which were already diagnosed, of 443 patients (136 men, 307 women). All patients who were 65 years of age or older and who had been admitted to the hospital for more than 7 days had fevers above 37.5 degrees C recorded. The etiologies of the 1,105 febrille episodes were respiratory tract infection in 381 (34.5%), urinary tract infection in 263 (23.8%), other diseases in 164 (14.8%) and in 297 (26.9%) unknown. The episodes were categorized into two groups by the degree of initial fever: group A, 559 episodes (50.6%) of 37.5-38.0 degrees C and group B, 546 episodes (49.4%) of above 38.0 degrees C. Of the episodes, 41.0% were one-day fevers, 21.4% two-day fevers, and 14.0% three-day fevers. The frequency of two-or-more-day fevers was significantly higher in group B (69.0%) than in group A (49.2%) (p < 0.001). In group B, respiratory tract infection (44.3%) was more frequent than urinary tract infection (16.1%) (p < 0.001). Of the respiratory tract infections, 63.5% were in group B and, in contrast, 66.5% of the urinary tract infections were in group A. The white blood cell count and C-reacting protein levels were significantly higher in group B than in group A (p < 0.001). The degree of initial fever is an important predictive marker of severity of disease in elderly patients.