Oxygen is a significant factor in wound healing. In normal wound healing, the wound either requires conditions of hypoxia or normal levels of oxygen (ie, normoxia). In the aerobic metabolism of glucose, cells use oxygen as the final electron acceptor to generate adenosine triphosphate (ATP), which fuels the majority of cellular processes during wound healing. During the inflammatory phase of wound healing, platelets and disintegrating cells can contribute ATP. This extracellular ATP can act as a signalling mechanism for many aspects of wound healing such as the immune response, inflammation, epithelial cells, and angiogenesis. During the inflammatory phase, the most significant cellular processes occur when oxygen is involved in the oxidative phosphorylation in the mitochondria which results in the production of ATP. Throughout the phases of wound healing there is a control of oxygen maintained in a narrow range. This point of normoxia is important because it is used to prevent abnormal periods of hypoxia or hyperoxia which can create damage to cell membranes.
Wound healing might be delayed in extreme hyperoxia which can cause growth arrest and cell death by mitochondria apoptosis.
This point of normoxia is the state of oxygenation where the cell or tissue does not report hypoxia nor does it report hyperoxia which would be oxygen toxicity.
Hyperbaric oxygen therapy (HBOT) is usually administered in a single patient or multipatient chamber that delivers 100% oxygen at 2 atmospheres of pressure. Hyperbaric oxygen therapy has proven to raise tissue oxygen 10 to 20 fold above room air.
Throughout all phases of wound healing, oxygen plays a substantial role. Its effects vary depending on whether the wound is in a hypoxic, normoxic, or in a hyperoxic state.
This study clarified that 1) oxygen is needed for mitochondrial cytochrome oxidase 2) oxygen is also involved in the hydroxylation of proline and lysine into procollagen, which leads to collagen maturation, 3) hypoxia is required to start the process of wound healing, 4) superoxide ion which kills bacteria, and 5) the level of evidence is moderate for the use of hyperbaric oxygen therapy (HBOT) for diabetic foot ulcers, crush injuries, and soft-tissue infections.
Chou WY conducted this study.
Authors Howard M. Kimmel; Anthony Grant, and James Ditata
Newspaper Wounds 2016;28(8)264-270