Immunosuppression of the burned patient

The burn patient is highly susceptible to infection due to the loss of the skin as a barrier to microorganisms. Immune defenses are activated in response to the burn injury; however, some of these defenses are altered. Neutrophil chemotaxis is compromised by decreased perfusion caused by hypovolemia and the formation of microthrombi. Chemotaxis and phagocytosis are dependent on complement components that are reduced in a large burn wound. Neutrophil intracellular killing power is reduced as oxygen delivery to the wound is decreased. Humoral immunity is altered with the drop in IgG levels. Cell-mediated immunity is depressed and T cell lymphocyte counts are deceased. Suppressor T cells are generated. Specific sources of infection for the burn patient include the patient's own bacterial flora; hospital personnel; respiratory equipment; and catheters, both urinary and intravascular. The best control for burn wound infection is the closure of the wound by early excision and grafting. When lack of donor sites prohibits this surgical therapy, control centers on the environment and wound care techniques. The selection of wound topical antibiotics on the basis of visual inspection and surface culturing assists in the prevention of burn wound sepsis. When wound sepsis does occur, systemic antibiotics are instituted. Although burn wound sepsis is an obvious cause of death for the burn patient, it is not the primary cause. Increasing sophistication in fluid resuscitation and in intensive care therapy has resulted in patients living beyond the initial insult and the following few days. Burn patient mortality is now associated with a syndrome presenting clinically as sepsis but without any identifiable septic source.(ABSTRACT TRUNCATED AT 250 WORDS)