Quemaduras y HBOT

THERMAL BURNS

The burn wound is a complex and dynamic pathophysiologic process characterized by a zone of coagulation, surrounded by a region of stasis, and bounded by an area of hyperemia. An intense inflammatory reaction leading to rapid edema formation, increased microvascular permeability, and sluggish blood flow results in thrombosis, ischemia, and advancing necrosis. The basic problems in repair of burns include susceptibility to infection, prolonged healing, and excessive scarring. These problems are greatly increased due to the loss of the integumentary barrier to bacterial invasion and compromised or obstructed microvasculature. These problems further prevent humeral and cellular elements from reaching the burned tissue as well as delayed regeneration and healing. The therapy of burns must be directed at minimizing edema, preserving marginally viable tissue, enhancing host defenses, and promoting wound closure. Adjunctive hyperbaric oxygen (HBO2) therapy can attack these problems, directly maintaining microvascular integrity, minimizing edema, and providing the substrate necessary to maintain viability.

RATIONALE: A significant body of data clearly supports the efficacy of HBO2 in the treatment of thermal injury. A reduction in fluid requirements, less conversion of partial to full thickness injury, preservation of marginally viable tissue, improved microcirculation, reduction in edema, faster epithelialization, less inflammatory response, enhancement of PMN killing, preservation of tissue creatine phosphate, adenosine triphosphate, and decreased wound lactate have all been reported. Infection remains the leading cause of death from burn injuries that are treated at burn centers. Therefore, control of infection is a major goal of therapy. Present evidence indicates that brief HBO2 exposures (2 ATA for 2 hrs) inhibit Pseudomonas aeruginosa both in vitro and in vivo. An intact microvasculature is a critical factor in the ability to provide cellular and humeral elements to the site of the injury. Any improvement in the microvasculature, whether it be preservation of intact capillaries or control of interstitial edema, would favorably influence the burn outcome. In human studies, HBO2 therapy has been shown to exert a positive, beneficial effect on the burn wound by: (1) reducing edema and plasma extravasation, (2) preserving the microcirculation, (3) preventing the conversion of partial to full thickness injury, and (4) maintaining the viability of the dermal elements which lead to a more rapid epithelialization. This has lead to a reduced need for surgery, a reduced length of hospital stay, and a reduced mortality rate. HBO2 therapy, used as an adjunct to traditional burn care, demonstrates greatest effects when initiated within the first 4 hours following the injury, or as quickly as possible.

Source: Hyperbaric Oxygen Therapy: A Committee Report. Undersea and Hyperbaric Medical Society. 1996 Revision.