A Closer Look At HBOT For Foot And Ankle Indications

Hyperbaric oxygen therapy (HBOT) can be a valuable adjunct treatment for foot and ankle wounds. Our panelists discuss the indications for HBOT, their personal experience with the treatment and keys to patient education on the modality.

Q:

What are your main indications for HBOT in the foot and ankle?

A:

Caitlin Garwood, DPM, notes her best clinical successes with HBOT has been for the acute stage of necrotizing/ascending limb infections in surgical limb salvage patients and in patients with compromised local flaps or wound closures. She and John Steinberg, DPM, generally utilize HBOT for one to two weeks in those patients and have seen “dramatic results” in those patient populations in comparison to the patients with chronic wounds.

Drs. Garwood and Steinberg will use HBOT for patients with a Wagner grade 3 ulcer. As they note, the wound must extend to the level of the bone and be non-healing with at least 30 days of standard wound care in order to receive HBOT. They also suggest proper offloading of the wound throughout the treatment period and maintaining adequate blood sugar control.

Kazu Suzuki, DPM, CWS, also most commonly uses HBOT for severe diabetic foot ulcers (Wagner Grade 3 or higher with gangrene and/or osteomyelitis). He also uses HBOT for failed skin grafts and flaps, and radiation injury (i.e. skin cancer on legs treated with radiation). Similarly, Enoch Huang, MD, MPH&TM, FACEP, FUHMS, FACCWS, notes the main foot and ankle indication for adjunctive HBOT is treating diabetic foot wounds that have not responded to standard wound care efforts such as incision and drainage, and debridement of deep space infections of the foot.

Patients with peripheral vascular disease (PVD) are also candidates for HBOT, notes Dr. Garwood. When patients present with evidence of vascular compromise, she and Dr. Steinberg typically refer them to vascular surgery. They note these patients must have optimal revascularization prior to the use of HBOT as the modality does not have any effect on large vessels with PVD.

Drs. Steinberg and Garwood add that transcutaneous oximetry (TCOM), which measures the transcutaneous oxygen partial pressure (PtcO₂), is a common test to determine if HBOT will add any benefit to healing. They note patients with diabetes must have a PtcO₂ value of 50 mmHg for the potential to heal and those without diabetes should have a PtcO₂ of 40 mmHg. During HBOT, Dr. Steinberg notes one can take serial TCOM measurements and should expect a rise of about 5 mmHg after two weeks with the goal being 40 to 50 mmHg. He and Dr. Garwood say a good predictor of whether HBOT will help wound healing is in-chamber PtcO₂. They note that a value of 200 mmHg or higher is a good predictor that HBOT will benefit the patient and help wound healing.  

In addition, Drs. Garwood, Steinberg and Huang will use HBOT for patients with refractory osteomyelitis. Specifically, they note candidates must have osteomyelitis that has not resolved with at least six weeks of appropriate antibiotic therapy and that the diagnosis of osteomyelitis is confirmed via bone culture, bone biopsy, magnetic resonance imaging (MRI) or computed tomography (CT) scan. There must also be evidence of either local (scar, radiation of the area, etc.) or systemic compromise of the host (diabetes, PVD, etc.), notes Dr. Garwood. She and Dr. Steinberg say the treatment of osteomyelitis with HBOT does not negate the need for aggressive surgical debridement to remove the infected bone with bony stabilization when necessary, a point Dr. Huang also emphasizes.  

Drs. Suzuki and Huang cite the Undersea and Hyperbaric Medical Society (UHMS) approved HBOT indications (available at www.uhms.org ). Dr. Suzuki adds that he tries not to stray from approved indications or “oversell” patients on the HBOT efficacy in wound healing.

“I have encountered many patients with venous ulcers and pressure ulcers who requested HBOT,” says Dr. Suzuki. “I believe it is my responsibility to educate them that we currently do not have any medical evidence to show that HBOT is efficacious in those diagnoses.”

Q:

What is your own experience with HBOT in your wound care practice?

A:

Following the published UHMS indications for HBOT, Dr. Huang utilizes HBOT when it is appropriate in patients with hypoxic and/or ischemic wounds.

“We have had good success in identifying patients for whom their wounds required adjunctive HBOT in order to heal and the patients who do not respond are usually ones who have not been able to adhere to our comprehensive treatment plan,” says Dr. Huang.

If a patient can stick with the prescribed treatment period, often 20 to 30 sessions, Dr. Suzuki believes HBOT is “exceedingly effective in healing wounds and treating infections and, in turn, saving many limbs.” He does acknowledge occasional problems with his patients dropping out of the treatment program because of the time commitment and logistics for them to commute to the HBOT center.

Drs. Steinberg and Garwood emphasize that HBOT is only an adjunctive therapy. They have found it is most useful and has the best success when one combines HBOT with comprehensive care including aggressive surgical management of the wound and the treatment of underlying diseases. Dr. Garwood says one must appropriately address the etiology of the wound with proper offloading, infection management and referral for revascularization when needed. Dr. Steinberg notes the team approach to limb salvage and the proper selection of patients for HBOT are critical to the success of this adjunctive treatment.  

Q:

How do you refer and prepare your patient before initiating HBOT therapy?

A:

Patients typically receive a multidisciplinary team approach, according to Drs. Steinberg and Garwood. They note patients must have medical optimization via their primary care physician. This consists of appropriate blood sugar control if the patient has diabetes and treatment of other underlying systemic diseases. Due to the vasoconstrictive effects of HBOT, they note that patients can have a decline in cardiac function. For this reason, Drs. Garwood and Steinberg say they typically want a patient’s ejection fraction to be 40 percent or greater. If the ejection fraction is under 40 percent, a cardiologist must evaluate these patients.

Prior to starting therapy, Dr. Garwood says patients must also have a chest X-ray that shows no evidence of an air trapping lesion. Dr. Steinberg adds that one can identify this better on a CT scan or ventilation/perfusion (VQ) scan when necessary. They emphasize that lung evaluation is a must to ensure there is not an untreated pneumothorax as this can cause further damage to the lungs and create a life-threatening condition.   

Performing wound care and HBOT in his practice, Dr. Huang says he and his colleagues are able to incorporate HBOT early in the evaluation and management process. He believes this leads to optimal outcomes. Dr. Huang advises that all patients must have prior or concomitant evaluation and treatment of the comorbidities known to affect wound healing by appropriate physicians (from vascular surgery, foot and ankle surgery, infectious disease, endocrinology) before initiating HBOT. Dr. Huang explains to patients that HBOT is only part of the treatment plan and failure to address all aspects of care will result in less than ideal outcomes. Dr. Suzuki concurs. He emphasizes to patients that HBOT is not a magic cure but rather an adjunctive therapy to proper wound care and antibiotic therapy.

Dr. Suzuki advises patients that HBOT is a logistically intensive treatment, ideally occurring five times per week (daily treatment Monday through Friday). However, he says patients can miss a few days occasionally as long as they can finish the prescribed course of treatment (20 to 30 sessions in most cases). Many of his dialysis patients get treatment on non-dialysis days. Dr. Suzuki recently had a patient who lived 100 miles away from the hospital. The patient commuted three times a week to complete 20 sessions over eight weeks, and had a great outcome, according to Dr. Suzuki.

Dr. Garwood is the Diabetic Limb Salvage Fellow at MedStar Georgetown University Hospital in Washington, DC.
 
Dr. Huang is the Medical Director of Wound Healing and Hyperbaric Medicine at Adventist Medical Center in Portland, Ore. He is an Affiliate Assistant Professor of Emergency Medicine at Oregon Health and Science University in Portland, Ore. He is also an Assistant Clinical Professor of Emergency Medicine at the Western University of Health Sciences in Pomona, Calif.

Dr. Steinberg is an Associate Professor at the Georgetown University School of Medicine. He is a Fellow of the American College of Foot and Ankle Surgeons.

Dr. Suzuki is the Medical Director of the Tower Wound Care Center at the Cedars-Sinai Medical Towers. He is also on the medical staff of the Cedars-Sinai Medical Center in Los Angeles and is a Visiting Professor at the Tokyo Medical and Dental University in Tokyo. Dr. Suzuki can be reached via e-mail at Kazu.Suzuki@CSHS.org .