Necrotizing Soft Tissue Infections

Necrotizing Soft Tissue Infections

Hyperbaric oxygen therapy is a recognized accepted adjunct to surgical debridements, antibiotic therapy and maximal goal-directed critical care therapy for infections of soft tissues resulting in necrosis. A number of clinical scenarios, specific lesions and syndromes have been described over the years, based on the affected tissues and location of infection, the etiologic organism or combination of organisms involved in the infection, and particular host immunologic and vascular risk factors. In all of these clinical situations, there appears to be the common denominator of the development of hypoxia resulting in necrosis and its progression.

Hypoxia is known to impair phagocytosis by polymorphonuclear leukocytes (PMNs). After an infective process is initiated, metabolic products of aerobic and anaerobic metabolism tend to lower the oxidation-reduction potential (Eh), leading to a drop in pH, which creates a milieu for growth of strict and facultative anaerobic organisms. When the blood supply to the skin is affected by involvement within a phlegmon, with edema and necrosis in the deep fascial layers in which they reside, the decreased perfusion pressure and ischemia predispose to rapid progression and advancement of the infectious process within the skin and subcutaneous tissues, exacerbated by the dysfunctioning polymorphonuclear leukocytes. Local hypoxia occurs, with upregulation of endothelial adherence molecules, resulting in leukocyte adhesion and endothelial cytotoxicity. Leukocytes may become sequestered in vessels, impairing local immunity, and incomplete substrate oxidation results in hydrogen and methane accumulation in the tissues. Tissue necrosis occurs, with purulent discharge and gas production. Quantities of gas within tissues are frequently seen in gas gangrene, crepitant anaerobic necrotizing cellulitis, and necrotizing fasciitis.

Hyperbaric oxygen therapy can reduce the amount of hypoxic leukocyte dysfunction occurring within an area of hypoxia and infection and provide oxygenation to otherwise ischemic areas, thus limiting the spread and progression of infection. The diffusion of oxygen dissolved in plasma in the circulation, where it is initially carried in large vessels, proceeds to areas of poorly perfused tissue, from regions of very high O2saturation down a gradient to lower oxygen levels in tissue. Integrin inhibition decreases leukocyte adherence, reducing systemic toxicity.

In cases where the antibiotic being used requires oxygen for transport across cell walls, hyperbaric oxygen therapy can act to enhance antibiotic penetration into target bacteria.

The above information was obtained from:
Jacoby I. Necrotizing Soft Tissue Infections.  Hyperbaric Oxygen Therapy Indications, 13th Edition, Undersea and Hyperbaric Medical Society, Best Publishing Comapany, FL; 2014

Additional indications for hyperbaric oxygen therapy may be discussed with your doctor and the Hyperbaric Medicine Team. Hyperbaric oxygen  therapy is usually used as an adjunct to additional care the patient is receiving. Additional treatments may also include antibiotic therapy, nutritional support, and surgical procedures, if indicated.  Our Hyperbaric Medicine Team will work closely with your physician(s) to coordinate any additional care needed.


Contact the Department of Hyperbaric Medicine at MemorialCare, Long Beach Medical Center for more information.

 

MemorialCare, Long Beach Medical Center
Department of Hyperbaric Medicine
2801 Atlantic Avenue
Long Beach, California 90806


Telephone: (562) 933-6960

 Fax: (562) 933-6060