Male gender is a risk factor for major infections after surgery

Background: Accumulating clinical and epidemiological evidence suggests sig nificant gender differences in the incidence of and outcome following major infection. in a rodent model of hemorrhagic shock, Investigators have show n that malts manifest depressed cell-mediated immunity that is reversed by castration or pharmacologic testosterone receptor blockade. Female rats, in contrast, show enhanced immune function that is reduced to male levels by testosterone administration. This sexual dimorphism is believed responsible for the improved outcome in female mice following septic challenge. Hypothesis: Male gender is a risk factor for major infections following sev ere injury. Design: Five-year prospective cohort study ending October 1998. Setting: Urban level I regional trauma center. Patients and Methods: A total of 545 trauma patients older than 15 years wi th an Injury Severity Score greater than 15 and survival more than 48 hours were prospectively identified and studied. Collected data included age, in jury mechanism. and Injury Severity Score. Major infections, defined as pne umonia, abdominal and pelvic abscess, wound infection requiring operative d ebridement, and meningitis, were tabulated. The occur rence of major infect ions in males and females was compared using multiple logistic regression a nalysis. Main Outcome Measurer Postinjury major infectious complications. Results: Of the 545 patients, 135 (24.8%) were female and 410 (75.2%) were male. Major infections occurred in 219 (40.2%) patients. Logistic regressio n confirmed that male gender is an independent risk factor for major infect ions (P=.04) after controlling for age and Injury Severity Score. Males had a 58% greater risk of developing a major infection (odds ratio, 1.58; 95% confidence interval, 1.01-2.48). Conclusions: Male gender is associated with a dramatically increased risk o f major infections following trauma. This effect is most significant follow ing injuries of moderate severity (Injury Severity Score 16-25) and persist s in all age groups.