Temporal characteristics of aspiration pneumonia in elderly inpatients: From resumption of oral intake to onset

BACKGROUND: Elderly inpatients who develop fevers after resumption of oral intake are often considered to have aspiration pneumonia (AP) and be tentatively fasted. Fasting has been associated with prolonged hospital stays and decreased swallowing ability. The purpose of this study was to compare AP and other infections after resumption of oral intake in elderly inpatients and to identify the clinical characteristics. PATIENTS AND METHODS: The records of patients who were admitted to a public tertiary hospital and referred for evaluation of swallowing disability were retrospectively reviewed to identify those who had developed AP, non-AP, or urinary tract infection (UTI) after resumption of oral intake. Eligible patients were enrolled consecutively in the study. The patient characteristics, physical findings, laboratory data, oral intake status at the time of onset of symptoms, and rate of discontinuation of oral intake after onset of infection were compared between the three types of infection. RESULTS: A total of 193 patients developed an infectious illness after resuming oral intake. Among them, 114 patients had a diagnosis of AP (n = 45), non-AP (n = 24), or UTI (n = 45). There were no significant differences in patient characteristics, physical findings or laboratory data between the group with AP and the other two groups. AP developed at a median of 6 (range 1–16) days after resumption of oral intake. The rate of discontinuation of oral intake was 91.1% in the AP group, 58.3% in the non-AP group, and 26.7% in the UTI group, respectively. CONCLUSION: Infectious diseases other than AP should be considered in the differential diagnosis when nosocomial fever develops in elderly inpatients more than 17 days after resuming oral intake. Furthermore, nosocomial fever after resuming oral intake has many causes other than AP, and discontinuation of oral intake should be carefully considered.