Making the case against hyperbaric oxygen

Abstract

HBOT. Osteoradionecrosis (ORN) is another condition which presents with a problem wound that may benefit from HBOT as adjunctive therapy. This benefit may be seen both in the treatment of established ORN or in its prevention during tooth extractions in high risk cases. However, HBOT is a valuable but expensive treatment modality and its indications must be thoroughly assessed to ensure satisfactory cost benefit from the therapy. Radiation therapy causes tissue injury with a change in the transcutaneous oxygen gradient and the sensitivity of macrophages. In wounds HBOT at 2.1 atmospheres results in a 40% increase in endothelial growth factor. In vitro HBOT affects fibroblasts after 15 to 120 minutes, increasing fibroblast growth. Clinically, HBOT has also been used to manage other irradiated tissue such as in delayed radiation injuries of the abdomen and pelvis. HBOT has also been used for soft tissue radionecrosis of the vagina. A thorough pre-treatment history and physical examination ensures the satisfactory physical condition of the patient and rules out absolute contraindications to HBOT such as conditions with a risk of gas trapping in the lungs like asthma. The relative contraindications to HBOT include sinus or middle ear disease which may necessitate pre-treatment myringotomy to avoid the complication of otic barotrauma. The adverse effects following HBOT may include oxygen toxicity which may result in seizures. The two factors regarding oxygen toxicity are oxygen intensity and the duration of exposure. The current therapy limits are based on experience and HBOT induced oxygen toxicity has a low incidence of 1 in 10-15,000 exposures. Other potential adverse effects may include visual changes such as myopia which may or may not resolve after treatment. The author will present data reflecting experience in the use of HBOT to manage ORN in 75 patients. Group A (51 patients) had been treated for overt ORN with HBOT alone, HBOT with sequestrectomy, or HBOT with sequestrectomy and reconstruction. Group B (24 patients at risk for developing ORN) had been treated with HBOT prophylactically for dental extractions. In group A, only 3 patients (5.9%) failed to show improvement. In group B, only one patient (4.2%) had complications during healing. The author will also present findings from an ongoing animal study involving the healing of critical sized calvarial defects and HBOT.