Postoperative fever is associated with infections in elderly patients aged 80 years or older after femoral intertrochanteric fracture surgeries

Background: Postoperative fever (POF) following orthopedic surgeries was generally secondary to inflammatory responses and most diagnostic tests were unnecessary according to previous reports. To our knowledge, there has been no literature discussing POF in elderly patients after femoral intertrochanteric fracture (ITF) surgeries. This study aimed to investigate the incidence of POF and the association between POF and infections in patients aged 80 years or older after ITF surgeries. Methods We retrospectively reviewed 128 patients aged 80 years or older after ITF surgeries. A postoperative body temperature ≥ 38ºC was defined as POF. Diagnostic tests conducted for POF were reviewed. Univariate analysis was used to compare the variables. Logistic regression was used to identify the independent risk factor of infections. Results 32 (25%) patients developed POF. Positive results were identified in 48.9% (22/45) of diagnostic tests. The positive rates of diagnostic tests were as follows: sputum cultures, 77.8% (7/9); urine cultures, 75% (3/4); urinalyses, 58.3% (7/12); chest radiographs, 36.4% (4/11); blood culture, 11.1% (1/9). The infection rate of the febrile patients was significantly higher than the afebrile patients (40.6% versus 17.7%, p = 0.008). After adjustment for age, sex and body mass index, POF was independently associated with infections (odds ratio = 3.4, 95% confidence interval = 1.4–8.1). In the febrile patients, the infection rate of patients who developed POF at postoperative day (POD) 2 or later was significantly higher than patients who developed POF within POD 1 (75.0% versus 29.2%, p = 0.022). Conclusions POF in patients aged 80 years or older following ITF surgeries was associated with postoperative infections. Diagnostic tests for respiratory and urinary systems were recommended for POF. POF occurred at POD 2 or later suggested increased infection risk in the febrile patients.