Hyperbaric Therapy for Skin Grafts and Flaps

Anatomy and Physiology

Free, partial-thickness skin grafts are reliant on the local accepting tissue and its microvasculature. Neovascularization is essential for acceptance of the donor tissue. Full-thickness rotation flaps are dependent on the main intact vasculature of the transfer area's pedicle.

Indications

There is no indication for hyperbaric oxygen therapy in uncompromised flaps and grafts. Situations, where HBO2 therapy is approved for skin grafts and flaps, includes various settings where there is a vascular compromise. Areas of past radiation exposure result in decreased micro vascularization and overall poor tissue conditions. Reperfusion injuries such as with crush injuries have shown to benefit from HBO2 therapy. Thermal burns with skin grafts are also indications for HBO2 therapy. [2]

Contraindications

Most contraindications to hyperbaric oxygen therapy are related to issues of barotrauma. This is when there is physical injury to an area where there is a closed air-filled space such as the lung or middle ear. Injury results from expansion of trapped gases with the changing pressure from the hyperbaric dive resulting in rupture of the compartment (perforation of a tympanic membrane or pneumothorax). The only true absolute contraindication is an untreated pneumothorax. Diving a patient in this situation will lead to fast progression of a tension pneumothorax and certain death. More relative contraindications are the presence of pulmonary blebs and emphysema with carbon dioxide retention. Administration of certain drugs is a relative contraindication. Disulfiram blocks superoxide dismutase which protects against oxygen toxicity (a known risk of hyperbaric oxygen therapy). Cisplatinum and sulfamylon impair wound healing. Bleomycin can cause interstitial pneumonitis. Sinusitis, seizures, pregnancy, and implanted devices such as pacemakers and epidural pumps are also relative contraindications. Claustrophobia, especially in cases of the monoplace chamber, can be an issue.[3]

Equipment

Hyperbaric oxygen therapy is administered in an approved and inspected the pressurized chamber. The chambers are either monoplace chambers which hold only one patient at a time or multiplace chambers which can accommodate several patients and an overseeing physician. 

The multiplace chambers can accommodate a wider variety of patients such as those on ventilators or those who need special accessory equipment that would not fit into a monoplace chamber. This activity regulates everything from the exhaust carbon dioxide to the purity of the oxygen and air. Frequent inspections are mandated, and the staff has to be specially trained to oversee hyperbaric dives. There is also a safety director appointed to each facility ensuring compliance with specifications. The most catastrophic event associated with a hyperbaric dive is a failure of the chamber or fire. Hopefully, the frequent inspections and keen vigilance of the staff will avoid failure of the chamber. Fire prevention is also at the forefront of concern with dives. Three things are needed for a fire; a combustible material, a spark or fire source, and oxygen. Patients are limited to what they can bring into the chamber. No oils, electronics, or other non-approved items are allowed. They must wear only specially approved gowns, and no street clothes are permitted. Patients are also grounded to prevent static sparks. Any non-approved electronic equipment can only be used away from the open chamber. [4]

Personnel

The physicians and all personnel including the cleaning staff must have special training in hyperbaric medicine and the chambers. Each overseeing physician must complete at least a 40-hour training course in hyperbaric medicine. Physicians can also get certified in undersea and hyperbaric medicine through a year-long fellowship. Hyperbaric techs must also take a 40-hour hyperbaric course. There is an appointed safety officer who has extra safety and maintenance training. Cleaning personnel must be aware of precautions needed to clean the acrylic monoplace chambers and the other special details in caring for and maintaining multiplace chambers.[5]

Technique or Treatment

Hyperbaric dives follow specific proven dive protocols depending on the condition being treated. Dives last 2 hours daily with two, 10-minute oxygen breaks to prevent oxygen seizures. They usually go to a pressure of 2.4 ATM at 100% oxygen. A typical dive routine lasts for 30 sessions but can be extended if it is felt to be beneficial. [6]

Complications

The most common complication of hyperbaric oxygen therapy is barotrauma. Barotrauma is caused by the expansion of gases in a confined space. The most common barotrauma is rupture or irritation of the tympanic membrane. Other more serious injuries include pneumothorax, rupture of small vessels, and damage to the inner, middle and external ear canals. More serious hazards include oxygen seizures, convulsions, and pulmonary edema and hemorrhage. Catastrophic complications are chamber fires and explosions.

Not all failed or compromised flaps or grafts respond to hyperbaric oxygen therapy. Prolonged treatments may be required. Loss of the flap or graft is a possibility that could require extensive debridement with loss of skin coverage. This could significantly increase patients' morbidity and mortality. [6]

Clinical Significance

Awareness of possible compromise or impending compromise of skin grafts and flaps is essential. Early initiation of hyperbaric oxygen therapy in these situations may lead to better results. [6]

Enhancing Healthcare Team Outcomes

Hyperbaric oxygen therapy has many uses. It is indicated for certain soft tissue conditions including compromised and ischemic skin grafts. The treating surgeon and wound care specialist must be aware of these indications in order to make the appropriate and timely referral for hyperbaric therapy. This will add to a better outcome and flap salvage for a certain percentage of patients who would otherwise be victims of failed grafts and poor outcomes.