Burn wounds infected with Pseudomonas aeruginosa triggers weight loss in rats

Sprague-Dawley rats (n = 21) were randomized into three groups: 1) burn only 2) burn and infection or 3) sham burn. Weight was monitored and blood was collected for cytokine ELISA, LPS quantification, and peripheral blood analysis. Animals were sacrificed either after 6 or 12 days.Infected animals showed substantial weight loss until day 6 post-burn as compared to burn alone. Endotoxin and TNF-α levels were elevated early in the infected burn group within 48 hours post-burn. In contrast, significant up-regulation of the anti-inflammatory cytokine IL-10 occurred later in the clinical course and was associated with the recovery from weight loss.Our results suggest that in the presence of infection, you get a SIRS response possibly due to transient endotoxemia that is only seen in the infection group. In contrast, both burn and infection get a late IL-10 (CARS) response, which is then associated with a return to normal weight in the infection group.While current procedures for burn injury management have improved patient prognosis, increased morbidity and mortality remains a major challenge for the clinician. Thus, identification of the mechanisms responsible for post-burn immune dysfunction and increased susceptibility to wound infection, subsequent sepsis and multiple organ failure under such conditions, is crucial for the development of improved treatment modalities. Thermal injury induces an immuncompromised state that predisposes patients to sepsis and multiple organ failure [1-6]. Skin, as the first line of defense against invading microbes, is equipped with an array of immune mediators capable of recruiting inflammatory cells to enable neutralization and clearance of bacteria and fungi [7,8]. Hence, immune failure in a burn patient who has lost the skin barrier is vulnerable to infection. These are major complications associated with burn trauma and recent evidence suggests that activation of a pro-inflammatory cascade plays an important role in their developmen