Presentation of infection in older patients--a prospective study

Traditional wisdom suggests that infections in older patients have atypical presentation, including blunted febrile response. Data are scarce.

We analyzed data from a prospectively collected database on presentation of infection in 4,308 patients, and compared the presentation of older patients (≥ 75 years) versus adults (< 75 years).

Single tertiary medical center.

Patients admitted with suspected bacterial infection during 2002-2004 and 2010-2011.

We evaluated clinical presentation on day of admission, including vital signs and laboratory parameters.

No difference in fever values as a presenting sign of infection was found between older patients and adults (median fever 38.3°C, interquartile range [IQR] 37.4-39.0°C; and 38.4°C, IQR 37.3-39.0°C, respectively, P = 0.08). Median leukocyte count was significantly higher in older patients (median 11.60, IQR 8.30-15.72 in older patients; 10.84, 7.50-15.00 in adults, P < 0.001). Presentation with septic shock, acute renal failure, and reduced consciousness was significantly more common in older patients. These findings were also consistent in the subgroups of bacteremic patients and patients with microbiologically documented infection.

Elevated fever and leukocytosis were found to be at least equally common in older patients compared to younger adults as part of the presentation of infection.