What is the role of hyperbaric oxygen therapy (HBOT) in wound healing for necrosis?

From the Guidelines

Hyperbaric oxygen therapy is conditionally recommended as an adjunctive treatment for wound healing in patients with necrosis, particularly those with diabetic foot ulcers, as it has been shown to improve wound healing and reduce ulcer area, although the evidence is limited and the certainty of evidence is low. According to the guidelines on interventions to enhance healing of foot ulcers in people with diabetes (IWGDF 2023 update) 1, hyperbaric oxygen therapy involves breathing 100% oxygen at a pressurized atmosphere of 2ATA or above, which increases the partial pressure of oxygen in hypoxic or ischemic tissues. This has been proposed as a key mechanism for improving wound healing in diabetes-related foot ulcers with ischemia or hypoxia.

The benefits of hyperbaric oxygen therapy include:

• Increasing oxygen concentration in tissues up to 10-15 times normal levels, which stimulates angiogenesis, enhances collagen production, activates stem cells, and fights infection by boosting white blood cell activity
• Improving wound healing and reducing ulcer area, as shown in a good quality study included in the systematic review for the guidelines 1
• Being a valuable therapy for diabetic foot ulcers, radiation injuries, compromised skin grafts, and crush injuries with compartment syndrome

However, it is essential to consider the following:

• The evidence behind the use of hyperbaric oxygen therapy is limited, and the certainty of evidence is low 1
• Patients should be assessed for suitability for hyperbaric oxygen therapy, and those with general frailty and comorbid conditions may have to be excluded from this treatment modality due to increased risks of adverse events
• Hyperbaric oxygen therapy requires large costs, and although several poor quality in-trial studies have demonstrated cost savings with its use, these fail to account for costs of construction of hyperbaric oxygen units 1

In addition to hyperbaric oxygen therapy, other gases such as topical oxygen, nitric oxide, ozone therapy, cold atmospheric plasma, and carbon dioxide have been studied, but the evidence is either limited or of low quality 1. As stated in the 2018 WSES/SIS-E consensus conference: recommendations for the management of skin and soft-tissue infections, consider adjuvant hyperbaric oxygen therapy in patients with necrotizing soft tissue infections (NSTI) after prompt debridement 1.

Hyperbaric oxygen therapy should be used as part of a comprehensive wound care approach that includes appropriate debridement, infection control, nutritional support, and offloading of pressure from the wound area. Patients should be monitored for potential side effects, including ear/sinus barotrauma, temporary nearsightedness, and rare oxygen toxicity.

From the Research

Hyperbaric Oxygen Therapy for Wound Healing and Necrosis

• Hyperbaric oxygen (HBO) therapy is a Medicare-approved treatment for chronic nonhealing wounds and radiation necrosis, using high pressures to saturate hemoglobin and dissolve oxygen into blood plasma to create a hyperoxemic environment 2.
• The therapy has been shown to aid in the healing of ulcerated wounds and reduce the risk of amputation in diabetic patients 3, 4.
• HBOT promotes wound healing by increasing nitric oxide production, which is associated with wound granulation tissue formation and improved wound closure 5.
• The therapy has been found to be effective in treating various types of wounds, including diabetic foot ulcers, arterial ulcers, and refractory osteomyelitis 3.
• HBOT has antimicrobial, immunomodulatory, and angiogenic properties, making it a potential treatment for a range of conditions, including inflammatory and systemic maladies 6.

Mechanisms of Hyperbaric Oxygen Therapy

• HBOT increases oxygen bioavailability in the blood and tissue, leading to hyperoxemia and hyperoxia 2, 6.
• The increased oxygen levels promote angiogenesis, collagen synthesis, and fibroblast proliferation, which are essential for wound healing 5, 4.
• HBOT has been shown to reduce the risk of infection and improve wound healing outcomes by promoting a hyperoxemic environment 3, 4.

Applications and Efficacy of Hyperbaric Oxygen Therapy

• HBOT has been found to be effective in reducing the risk of amputation in patients with diabetic foot ulcers 3.
• The therapy has been shown to promote healing of arterial ulcers, calciphylactic and refractory vasculitic ulcers, and refractory osteomyelitis 3.
• HBOT has been found to be associated with remission of about 85% of cases of refractory lower extremity osteomyelitis 3.