Supplementing Diabetic Wound Care With Hyperbaric Medicine
However, within 15 minutes of HBOT, endothelial cells begin to proliferate. After 120 minutes, fibroblasts begin to produce a response, which can last up to 72 hours post-exposure.10 There are also effects in red blood cells as hyperbaric oxygen increases their deformability and improves the ability of these cells to pass through narrow capillaries. Leukocytes use oxygen to create high-energy radicals and their rate of formation is directly proportional to the amount of oxygen available. Leukocytes can then lend these radicals to neutrophils for increased phagocytosis of bacteria, helping to clean the wound and prevent infection.11
Is The Patient A Viable Candidate For HBOT?
When assessing whether a diabetic foot ulceration meets criteria for HBOT, Medicare requires that the wound be staged as a Wagner III (a full thickness ulceration having bone and/or soft tissue infection present) ulcer, which has failed standard care for at least 30 days.12 Hyperbaric oxygen therapy is also indicated for the treatment of gas gangrene and progressive necrotizing infections as an adjunct to surgical debridement and antibiotic therapy. Hyperbaric oxygen therapy can also be indicated for use with the preservation of skin grafts and flaps if concerns of failure are present. Furthermore, if the graft or flap does fail, one can use HBOT to prepare the wound bed for the next graft or flap.
The use of transcutaneous oxygen pressure (TcPO2) measurements offers a simple and noninvasive diagnostic technique to provide a reliable objective assessment of the local skin perfusion in room air. One can also use TcPO2 measurements to gauge the effect HBOT might have on local tissue by measuring changes in perfusion while supplementing the patient with 100% O2 via a mask or a nasal cannula.The results of this test show if the patient has the ability to heal a wound by way of tissue perfusion in room air and if one can achieve a benefit via supplementation with HBOT.13 It should be noted that in the presence of infection, there is a local decrease in tissue oxygen perfusion that does resolve once the infection is eradicated.14
What About Contraindications For HBOT?
Hyperbaric oxygen therapy is not without risks and proper patient selection is important. If patients are taking the chemotherapeutic drug doxorubicin, HBOT is contraindicated as the drug can become cardiac toxic and lead to death.
The use of Sulfamylon® (UDL Laboratories) cream on a wound is also contraindicated when a patient undergoes HBOT as this leads to local CO2 buildup and vasodilatation, which is further compounded by central vasoconstriction caused by HBOT. One should utilize a different topical wound agent or remove the ointment from the wound before starting a HBOT treatment.
Untreated pneumothorax is also a contraindication. It is of benefit to screen patients with a chest radiograph to rule this out before starting HBOT. Other conditions that present a risk with HBOT include: seizure disorders, emphysema with CO2 retention, uncontrolled high fevers, a history of spontaneous pneumothorax, chronic sinusitis and upper respiratory tract infections, viral infections, a history of optic neuritis, previous otosclerosis surgery and congenital spherocytosis.8 However, authors have noted that one can take possible precautions if one of these conditions is present in order to allow HBOT to proceed.8
Case Study: When A Patient With Diabetes Has An Involved Infection With Gas Gangrene
A 66-year-old male with type 2 diabetes mellitus had an involved infection with the presence of subcutaneous gas gangrene in the lateral foot. The patient subsequently had a wide margin excisional debridement and partial fifth ray resection. The resulting foot had an exposed bone of the fourth metatarsal shaft and the fifth metatarsal base as well as concerns of further tissue loss occurring due to local ischemia.