The effect of sepsis on wound healing

Normal wound healing is a regulated sequence of events that successfully restore tissue integrity. Previous studies have suggested that wound healing is impaired in a septic host. The current study examines the effect of sepsis on the inflammatory and proliferative phases of wound healing at a remote site of secondary injury.

Polyvinyl alcohol sponges, either inoculated with a standard dose of Pseudomonas aeruginosa (experimental) or soaked in normal saline (control), were placed subcutaneously in the anterior abdominal region of male B6D2F1 mice. Immediately following sponge placement, full thickness excisional dermal wounds were created on the dorsum. Wound healing was examined at days 3, 5, and 7 postinjury. The infiltration of neutrophils and macrophages into wounds was quantified, and the reepithelialization rate and collagen content were measured.

Peripheral neutrophil counts were significantly elevated in infected mice, yet neutrophil content of the remote wound of infected animals was significantly reduced (5% of control, P < 0.05). Wounds of infected mice also showed a 30% reduction in the macrophage content. Wounds of infected animals exhibited delayed reepithelialization (76 +/- 3 vs 97 +/- 3% at day 5, P < 0.05) and collagen synthesis (55.3 +/- 9.5 vs 105 +/- 13.0 microg/wound, P < 0.05).

Systemic infection alters both the inflammatory and the proliferative processes at remote sites of injury. Multiple factors seem likely to contribute to the increased incidence of wound complications in septic patients.