EpiFLO^® utilizes leading-edge oxygen concentration technology to stimulate tissue regenerative processes driving closure of delayed-healing acute or chronic wounds. EpiFLO^® is a light-weight (~100 g) oxygen ‘fuel cell’ concentrator (i.e. no moving parts; operates silently) that continuously delivers oxygen (concentrated to nearly 100% from ambient air) to the wound site. The product is US FDA approved (for a broad range of indications) as a Class III Medical Device; prescribed or on order by a physician. It is also ISO13485 and Health Canada certified (Class II; no physician prescription / order required in Canada).

Sustained Oxygen Delivery (with EpiFLO^®) for Rapid Wound Healing: Wound healing is a complex biological process that requires the successful mobilization and integration of cells to repopulate the wound and lay down the tissue extracellular matrix. This process is orchestrated, at least in part, by a number of growth factors. Optimal metabolic function of these cells is critical for the success of this process which implies that oxygen be available. Although it has been suggested that some degree of hypoxia may stimulate normal wound repair, chronic wound ischemia is a clearly pathological condition that inhibits normal wound healing. Oxygen plays an essential role in energy metabolism, and is important for polymorphonuclear cell function, neovascularization, fibroblast proliferation and collagen deposition – all of which are critical in wound repair. It has been now well established that many antibiotics (e.g. vancoymycin, gentamicin) have an absolute need for adequate levels of oxygen present to work properly. Mechanisms of action of oxygen in wound healing are briefly outlined below:

Hypoxia delays wound healing: Many clinical observations, strongly supported by experimental evidence in animals, have led to the conclusion that wound healing is delayed under hypoxia. Ischemic ears in this rabbit ear model have tissue oxygen tensions of approximately 24 mmHg versus the level of 53 mmHg measured in non-ischemic ears¹. Oxygen electrodes implanted in chronic wounds have indeed recorded conditions of hypoxia compared to controls². Hypoxia blunts energy metabolism, collagen synthesis, and neovascularization³.

Oxygen as an infection control agent: Leukocytes kill bacteria most effectively when supplied with abundant oxygen. The rate of bacterial killing may be directly dependent on oxygen tension⁴ Phagocytosis stimulates a huge, often five-fold increase in oxygen consumption, the so-called “respiratory burst.” At least 98 percent of this oxygen is converted to superoxide anion, peroxide, and other reactive oxygen species (ROS) which, when released into phagosomes, are lethal to many bacteria. This oxidative mechanism is most effective in high PO2, even up to several hundred millimeters of mercury⁵. Hunt et al. showed that oxidative and antibiotic killing of bacteria are independent mechanisms and are additive in wounds⁶. In a human study of colorectal surgical patients, a direct correlation between decreased subcutaneous partial pressure of oxygen and the resulting increase in postoperative wound infection rate has been shown⁷.

Growth Factors: Increased production of oxidants, hydrogen peroxide and O2, stimulate macrophages to produce angiogenic substances that are both chemoattractant and growth factors to endothelial cells. The most important of these in wounds appears to be VEGF (Vascular Endothelial Growth Factor). VEGF secretion responds to mild exposure to oxidates and lactates, stimulants that are not inhibited by hyperoxia. In fact, they are enhanced by elevated oxygen tensions. Oxygen may have direct influence on keratinocytes since the keratinocytes are the most likely cell type to encounter the increased oxygen tensions because they are at the surface of the wound. Oxygen stimulates their metabolism and consequent cell migration and growth factor production.

Collagen Synthesis is dependent on Oxygen: Molecular oxygen is essential during collagen synthesis and for stable cross-linking leading to enhanced healed wound stability. In a clinical study, collagen deposition was determined in patient wounds. The amount of deposited collagen was directly proportional to the measured tissue oxygen tensions⁴.

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¹ Tandara A and Mustoe T. Oxygen in wound healing – More that a nutrient. World J Surg 28, 294-300,2004.
² Silver IA. The measurement of oxygen tension in healing tissue. In Herzog H. ed. Progress in Respiration Research III. Basel, Switzerland: S. Karger; 1969: 124-135.
³ Albina J, Reicner J. Oxygen and the regulation of gene expression in wounds. Wound Rep Reg 2003;11:445-451
⁴Hohn DC. Oxygen and leukocyte microbial killing. In Davis JC and Hunt T, eds. Hyperbaric Oxygen Therapy. Bethesda, Undersea Med. Soc. 1997: 101-110.
⁵ Cianci Paul. Advances in the treatment of the diabetic foot: Is there a role for adjunctive hyperbaric oxygen therapy? Wound Rep Reg 2004;12:2-10
⁶ Knighton DR, Hunt TK, Scheuenstuhl H, et al. Oxygen tension regulates the expression of angiogenesis factor by macrophages. Science 1983;221:1283-5.
⁷ Gottrup F. Oxygen in wound healing and infection. World J Surg. 28, 312-315, 2004.

Oxygen Stimulates Angiogenesis: Recent studies^8,9 have shown increased formation of new blood vessels (i.e. neo-angiogenesis) in wounds treated with oxygen, compared to controls. The ability of oxygen to stimulate angiogenesis is an important component in the ability of oxygen therapy to heal large and deep wounds in both diabetic and venous stasis patients.

Products Benefits of EpiFLO® Oxygen

The advantages of using EpiFLO® are numerous: Works with your existing wound dressings – you don’t have to change your practice Simple to use, installs in 1-2 minutes Oxygen delivery cannula readily installs on any anatomic site Operate 24/7 for extended therapeutic durations Small size allows patients to be ambulatory and allows normal daily activities Silent operation – no moving parts Can reduce wound dressings and ancillary costs Convincing economic advantages and wound care costs Compatible with both outpatient and inpatient health care