Burn wound infection and sepsis

Infection remains the most common cause of morbidity and mortality in burn patients.A variety of factors increase the risk of developing invasive burn wound infection (burn wound sepsis). Individuals who sustain a TBSA burn > 20 percent are at particularly high risk; Other factors include delays in burn wound excision, extremes in age (very old, very young), and impaired immunity. Microbial factors, such as type, virulence, and bacterial count (> 105 organisms per gram of tissue), increase the risk of an invasive wound infection.The organisms that can colonize the burn wound and potentially give rise to burn wound infection vary with time and location.The recognition of burn wound infection remains challenging due to the many features unique to a burn injury. A rapid change in the clinical condition of the burn patient, such as increasing pain or changes in the gross appearance of a burn wound or skin graft donor sites; intolerance of enteral feedings; or systemic signs, is indicative of burn wound infection and potentially burn wound sepsis.When wound infection is suspected clinically based upon clinical features, quantitative wound cultures and examination of histopathology obtained by biopsying the wound are necessary to confirm the diagnosis of burn wound infection (> 105 bacteria per gram of tissue), which may or may not be invasive.Criteria used for a diagnosis of sepsis in unburned patients often does not apply in burn patients, particularly severely burned patients, due to alterations of the patient s metabolic profile by inflammatory mediators. The burn sepsis definition distinguishes physiologic changes that occur secondary to the hypermetabolic response of the burn itself from those that result from microbial infection. Specific criteria have been suggested by the American Burn Association.Depending upon the burn wound category, treatment of burn wound infection consists of a combination of burn wound care (ie, cleansing, dressings), topical antimicrobial therapy, systemic antimicrobial therapy, and burn wound debridement or excision. Noninvasive burn wound infection is characterized by typical clinical features of burn wound infection without systemic signs, bacterial count > 105 bacteria per gram of tissue (or recovery of mold or yeast by culture), and no microbial invasion into unburned tissue. Treatment consists primarily of topical antimicrobial therapy and burn wound excision for unexcised wounds, and possibly reexcision for excised wounds. Invasive burn wound infection is characterized by typical clinical features of burn wound infection and systemic signs, bacterial count > 105 bacteria per gram of tissue obtained from a burn wound or eschar, and microbial invasion into unburned tissue. Treatment is initiated with systemic broad-spectrum antimicrobial therapy and excision of all infected tissue to healthy tissue bed as determined by intraoperative biopsy. Specific antimicrobial therapy is guided by the results of burn wound culture and histopathology.