Background: Hospital-acquired infections (HAI) in trauma patients increase inpatient morbidity and mortality. However, their impact on long-term mortality is not well understood.
Patients and methods: A retrospective trauma registry analysis of all patients admitted to an academic level I trauma center between July 1, 2008 and December 31, 2012 was performed. Patients included survived to discharge and were 18 years of age or older. Age, gender, Injury Severity Score (ISS), ventilator use, history of chronic obstructive pulmonary disease (COPD), and HAI were reviewed. Name, social security number, and date of birth were used to extract National Death Index data from 2008-2013 for an outcome of mortality after discharge, time to death, and cause of death. Unadjusted logistic regression was performed. Multiple logistic regression was used to adjust for patient and injury characteristics and to determine odds of mortality in the post-discharge period.
Results: A total of 8,275 patients met inclusion criteria; 65.4% were male and the median age was 47. The mean ISS was 11 ± 8.9. Nine hundred seventeen patients (11.1%) died after discharge; 4.8% of patients had hospital-acquired pneumonia (HAP) and 4.2% had a urinary tract infection (UTI). The unadjusted odds ratio (OR) of mortality after discharge in patients who had pneumonia and UTI were 1.77 (1.35, 2.31, p < 0.001) and 2.44 (1.87, 3.17, p < 0.001), respectively. After adjusting for patient age, gender, ISS, ventilator use, and history of COPD (pneumonia patients only), the odds for mortality after discharge remained significant for pneumonia (OR = 1.57 (1.09, 2.23), p = 0.013) but not for UTI (OR = 1.25 (0.93, 1.68), p = 0.147). The top causes of death after discharge in patients with HAP were COPD (11.4%) and falls (7.1%).
Conclusions: Trauma patients with HAP have higher mortality after hospital discharge. Prevention strategies for HAP including pulmonary toilet, early mobility, pain control, and early extubation must be a priority. Unfortunately, patients who develop pneumonia may have a decreased reserve, or ability to recover from their traumatic injuries and HAI. Further characterization of HAP and its subsequent treatment strategies are needed.
Keywords: infection; mortality; trauma.