Cutaneous Vascular Compromise
At our institution, a 36-year-old man was referred to the dermatology clinic 2 days after undergoing embolization of a symptomatic arteriovenous malformation in the right knee (Figure 3A). The procedure was complicated by cutaneous purpura concerning for necrosis, a known complication of this procedure. We referred the patient for evaluation to consider HOT. Although he was outside the ideal window for starting treatment, HOT was initiated. With a late start in treatment, areas of skin had already progressed to full necrosis, which did not respond to treatment; however, contiguous areas that initially looked very similar clinically did respond to treatment (Figure 3B). This case suggests a penumbralike effect in which vulnerable tissue that would most likely have been lost was salvaged by HOT.
Figure 3. A, Purpuric skin at presentation 2 days after the patient underwent embolization of a symptomatic arteriovenous malformation of the right knee. B, Several months after hyperbaric oxygen therapy, the medial aspect of the knee was fully necrosed at presentation, but the lateral aspect of the knee was salvaged.
Ischemia
Hyperbaric oxygen therapy has been used to treat ischemia caused by injection of cosmetic filler. Henderson et al21 described a 37-year-old woman who experienced occlusion of the left superficial temporal artery while self-injecting a hyaluronic acid filler around the temples. The problem was complicated by left-sided hearing loss, cutaneous blanching of the left face, and pain. She was treated with enoxaparin, aspirin, dexamethasone, antibiotics, and intradermal lidocaine. Additionally, she was urgently referred to a HOT facility and was treated with 6 HOT treatments in 3 days, with the first treatment provided 15 hours after the initial insult. The patient showed a decrease in ischemic discoloration over the course of the treatment. Eventually, her hearing returned to baseline and she achieved an acceptable cosmetic outcome.21
Uittenbogaard et al22 reported the treatment of a patient who experienced dermal ischemia after receiving calcium hydroxylapatite at an aesthetic clinic. She did not improve with standard treatment but subsequently experienced resolution of symptoms after treatment with HOT. She had an excellent cosmetic outcome at 6-month follow-up.22
Complications and a Contraindication
Hyperbaric oxygen therapy generally is safe, but there is potential for complications.
Fire
This rare risk has a catastrophic outcome.23 Standards for fire prevention in hyperbaric facilities are issued by the National Fire Protection Association, covering construction and building materials, lighting, electrical wiring, exposure to flammable materials, and other possible ignition sources.24
Middle Ear Barotrauma
The incidence of the most common adverse effect of HOT is reported at 2% to 30%.7,25 Middle ear barotrauma occurs most commonly during the compression phase of treatment. It is more common in patients treated in a monoplace chamber because they are kept supine and are less able to regulate middle ear pressure.26 Symptoms of middle ear barotrauma can be relieved by teaching patients autoinflation technique, such as the Valsalva maneuver, or by placing tympanoplasty tubes.27
Reversible Myopia
Caused by direct O2 toxicity to the lens, this complication can last for weeks, though it eventually resolves spontaneously. Reversible myopia has been reported to be at least as common as middle ear barotrauma.27
Other Complications
Central nervous system complications, such as seizures, and pulmonary O2 toxicity are rare, more serious complications.27
Untreated Pneumothorax
The only absolute contraindication to HOT, pneumothorax can decompensate during HOT if left untreated. However, HOT can proceed once pneumothorax is addressed.7
Conclusion
Hyperbaric O2 therapy can make a positive contribution to the dermatologic therapeutic armamentarium, in specific patients, for impending graft or flap failure, chronic wounds and ulcerations, and cutaneous vascular compromise. Although HOT is not a commonly needed treatment in dermatology, it is important to be aware of its potential because delay in treatment can decrease its effectiveness. It is recommended that dermatologists locate the nearest HOT facility and become familiar with its capabilities.