A number of types of soft tissue infections may benefit from adjunct treatment with hyperbaric oxygen and are included in the category of “necrotizing soft tissue infections.” Names of such clinical syndromes include crepitant anaerobic cellulitis, progressive bacterial gangrene, necrotizing fasciitis, and nonclostridial myonecrosis. Gas gangrene (clostridial myositis and myonecrosis) is a separate entity and is reviewed elsewhere in this information.
Necrotizing soft tissue infections may result from either a single strain or a mixed population of bacteria and typically occurs after trauma, surgery and/or contact with foreign bodies. The individual affected by such infections frequently has complicating conditions such as diabetes or vascular disease.
In addition to pre-existing complications, necrotizing soft tissue infections themselves may induce conditions adverse to control of the infection by normal defense mechanisms. The infections commonly lower tissue oxygen levels, impairing the ability of the white blood cells (neutrophils) to fight infection. Toxins produced by bacteria may also inhibit neutrophil activity.
The primary treatments for necrotizing soft tissue infection are surgical removal of infected tissue and administration of the appropriate antibiotics. In selected cases, the addition of hyperbaric oxygen therapy may be both lifesaving and cost effective. Hyperbaric oxygen may be beneficial in several ways. Some of the bacteria involved in necrotizing soft tissue infections are “anaerobic,” growing most rapidly in a low oxygen environment. In the hyperbaric chamber, tissue oxygen levels may be raised sufficiently to inhibit bacterial growth. In addition, hyperbaric oxygen treatment may enhance the ability of neutrophils to kill bacteria.
The use of hyperbaric oxygen for treatment of necrotizing soft tissue infections should be individualized. In specific instances where risk of morbidity and mortality are high, adjunct hyperbaric oxygen therapy should be considered.