1. Aetna considers systemic hyperbaric oxygen therapy (HBOT) medically necessary for any of the following conditions:
   1. Non-healing infected deep ulcerations (reaching tendons or bone) of the lower extremity in diabetic adults unresponsive to at least 1 month of meticulous wound care (including aggressive debridement, maximal antibiotic therapy, tight glycemic control, and appropriate treatment of arterial insufficiency, including revascularization if necessary). HBOT is not considered medically necessary for superficial lesions.
   2. Acute carbon monoxide poisoning
   3. Decompression illness (“the bends”)
   4. Acute air or gas embolism
   5. Gas gangrene (Clostridial myositis and myonecrosis)
   6. Cyanide poisoning (with co-existing carbon monoxide poisoning)
   7. Acute traumatic peripheral ischemia (including crush injuries and suturing of severed limbs) when loss of function, limb, or life is threatened and HBOT is used in combination with standard therapy
   8. Acute peripheral arterial insufficiency (i.e., compartment syndrome)
   9. Progressive necrotizing soft tissue infections, including mixed aerobic and anaerobic infections (necrotizing fasciitis, Meleney's ulcer)
   10. Chronic refractory osteomyelitis, unresponsive to conventional medical and surgical management
   11. Compromised skin grafts and flaps
   12. Radiation necrosis (osteoradionecrosis, myoradionecrosis, brain radionecrosis, and other soft tissue radiation necrosis) 
   13. Radiation proctitis
   14. Exceptional blood loss anemia only when there is overwhelming blood loss and transfusion is impossible because there is no suitable blood available, or religion does not permit transfusions
   15. Pneumatosis cystoides intestinalis
   16. Prophylactic pre- and post-treatment for members undergoing dental surgery of a radiated jaw
   17. Acute cerebral edema
   18. Idiopathic sudden deafness, acoustic trauma or noise-induced hearing loss, when HBOT is initiated within 3 months after onset.

2. Aetna considers the use of systemic HBOT experimental and investigational for the following conditions (not an all inclusive list) because there is insufficient evidence in the medical literature establishing that systemic HBOT is more effective than conventional therapies:
   1. Actinomycosis and other mycoses
   2. Superficial and/or non-infected diabetic ulcers
   3. Non-diabetic cutaneous, decubitus, pressure and venous stasis ulcers
   4. Chronic peripheral vascular insufficiency
   5. Acute renal arterial insufficiency
   6. Acute or chronic cerebrovascular insufficiency/accident (including thrombotic or embolic stroke)
   7. Anaerobic septicemia and infection other than clostridial
   8. Aerobic septicemia and systemic aerobic infection
   9. Pyoderma gangrenosum
   10. Intra-abdominal abscess, pseudomembranous colitis (antibiotic-induced colitis)
   11. Intracranial abscesses
   12. Skin burns (thermal)
   13. Acute thermal and chemical pulmonary damage, i.e., smoke inhalation (e.g., carbon tetrachloride, hydrogen sulfide) with pulmonary insufficiency
   14. Tetanus
   15. Organ transplantation and storage
   16. Pulmonary emphysema
   17. Cognitive impairment (e.g., senility, senile dementia)
   18. Non-vascular causes of chronic brain syndrome (e.g., Pick's disease, Alzheimer's disease, Korsakoff's disease)
   19. Multiple sclerosis
   20. Migraine or cluster headaches
   21. Meningitis
   22. Closed head and/or spinal cord injury
   23. Myocardial infarction
   24. Cardiogenic shock
   25. Sickle cell crisis or hematuria
   26. Radiation-induced cystitis, myelitis, enteritis
   27. Bone grafts or fracture healing (e.g., nonunion fractures)
   28. Arthritic diseases
   29. Ophthalmologic diseases (including diabetic retinopathy, retinal detachment, central retinal artery occlusion, radiation injury to the optic nerve, glaucoma, keratoendotheliosis)
   30. Hepatic necrosis
   31. Lepromatous leprosy
   32. Arthritis
   33. Aseptic necrosis of the femoral head and neck
   34. Cystic acne
   35. Melasma
   36. Actinic skin damage
   37. Lyme disease
   38. Cerebral palsy
   39. Reflex sympathetic dystrophy (complex regional pain syndrome)
   40. Necrotizing arachnidism
   41. Bell's palsy
   42. Legg-Calve Perthes disease
   43. Crohn's disease
   44. Osteoporosis
   45. Cancer
   46. HIV infection
   47. Facial neuritis
   48. Tinnitus
   49. Interstitial cystitis
   50. Acute coronary syndrome
   51. Ischemia due to lupus vasculitis
   52.  Autism.  

3. Aetna considers systemic HBOT experimental and investigational for members with any of the following contraindications to systemic HBOT, as the safety of systemic HBOT for persons with these contraindications to HBOT has not been established:
   1. Untreated pneumothorax
   2. Concurrent administration of doxorubicin, cisplatin, or disulfiram
   3. Premature infants (birth prior to 37 weeks gestation).

4. Aetna considers topical HBOT administered to the open wound in small limb-encasing devices experimental and investigational because its efficacy has not been established through controlled clinical trials.

Hyperbaric oxygen therapy (HBOT) is defined as systemic treatment in which the entire patient is placed inside a pressurized chamber and breathes 100% oxygen under a pressure greater than one atmosphere. It is used to treat certain diseases and conditions that may improve when an increased partial pressure of oxygen is present in perfused tissues.

The literature states that HBOT should not be a replacement for other standard successful therapeutic measures. Depending on the response of the individual patient and the severity of the original problem, treatment may range from less than 1 week to several months' duration, the average being 2 to 4 weeks. HBOT treatment for more than 2 months is usually not necessary.

HBOT has been shown to be an effective method for treating diabetic foot wounds in carefully selected cases of lower extremity lesions. Although the results of multiple retrospective studies involving a significant number of patients have consistently indicated a high success rate in patients who had been refractory to other modes of therapy, several recent prospective, randomized studies have only supported the adjunctive role of systemic hyperbaric oxygen therapy in the treatment of non-healing infected deep lower extremity wounds in patients with diabetes. Such evidence is lacking, however, for superficial diabetic wounds and non-diabetic cutaneous, decubitus, and venous stasis ulcers.

A number of technology assessment organizations, including the Cochrane Collaboration, the Wessex Institute, the Alberta Heritage Foundation for Medical Research, and the Agency for Healthcare Research and Quality (AHRQ), have systematically reviewed the evidence supporting the use of hyperbaric oxygen for each of the indications for which it has been used.

An evidence review conducted by the Alberta Heritage Foundation for Medical Research (Hailey, 2003) concluded that use of HBOT is not supported for a number of conditions, including non-diabetic wounds, multiple sclerosis, cerebral palsy, decubitus ulcers, necrotizing arachnidism, actinomycosis, cardiovascular conditions, Bell's palsy, cluster and migraine headaches, Legg-Calve Perthes disease, Crohn's disease, osteoporosis, cancer, head trauma, cognitive impairment, senile dementia, glaucoma, keratoendotheliosis, HIV infection, facial neuritis, and nonunion of fractures. 

A systematic evidence review conducted for the Agency for Healthcare Research and Quality (AHRQ) (McDonagh, et al., 2003) found insufficient evidence to support the use of HBOT in brain injury. The assessment concluded that “The balance of benefits and harms of HBOT for brain injury, cerebral palsy, or stroke has not been adequately studied.”

Denton, et al. (2004) systematically reviewed the evidence regarding HBOT for radiation cystitis. Of the 19 studies that met inclusion criteria, all the reports were case series and only one was a prospective series. The authors stated that “[t]he level of evidence that these data represent is essentially IIIC (weak evidence), apart from one prospective case series of forty patients.” The latter study (Bevers, et al., 1995) was graded IIC (prospective study without calculation of sample size and without accurate and standard definition of outcome variables).

In a Cochrane review, Bennett, et al. (2005) concluded that for people with acute coronary syndrome, individual small trials suggest the addition of HBOT reduced the risk of major adverse cardiac events, some dysrrhythmias, and reduced the time to relief from ischemic pain, but did not reduce mortality. They noted that in view of the modest number of patients, methodological shortcomings and poor reporting, this result should be interpreted cautiously, and an appropriately powered trial of high methodological rigor is justified to define those patients (if any) who can be expected to derive most benefit from HBOT. The routine application of HBOT to these patients cannot be justified from this review.

A Cochrane review (Bennett, et al., 2005) assessed the evidence of effectiveness of HBOT for long-term radiation injury to the anus and rectum.  The investigators found HBOT significantly improved chance of healing for radiation proctitis (relative risk 2.7, 95% confidence interval 1.2 to 6.0). The investigators concluded that small trials suggest that HBOT is useful for treatment of long-term radiation injury to the anus and rectum.

Absolute contraindications to hyperbaric oxygen therapy include: untreated pneumothorax, concurrent administration of disulfuram (Antabuse); concurrent administration of the antineoplastic agents doxorubicin and cisplatinum; and administration to premature infants (due to risk of retrolental fibroplasia). Relative contraindications to the use of hyperbaric oxygen therapy include prior chest surgery, lung disease, viral infections, recent middle ear surgery, optic neuritis, seizure disorders, high fever, congenital spherocytosis, and claustrophobia.

Topical HBOT administered to the open wound in small limb-encasing devices is not systemic HBOT and its efficacy has not been established due to the lack of controlled clinical trials. In addition, in vitro evidence suggests that topical HBOT does not increase tissue oxygen tension beyond the superficial dermis. Examples of topical HBOT devices are TOPOX portable hyperbaric oxygen extremity and sacral chambers (Jersey City, NJ), Oxyboot and Oxyhealer from GWR Medical, L.L.P. (Chadds Ford, PA).

The Undersea and Hyperbaric Medical Society issued the following policy statement on topical oxygen, often referred to as “topical hyperbaric oxygen therapy” (Feldmeier, et al., 2005): “1. Topical oxygen should not be termed hyperbaric oxygen since doing so either intentionally or unintentionally suggests that topical oxygen treatment is equivalent or even identical to hyperbaric oxygen. Published documents reporting experience with topical oxygen should clearly state that topical oxygen not hyperbaric oxygen is being employed. 2. Mechanisms of action or clinical study results for hyperbaric oxygen cannot and should not be co-opted to support topical oxygen since hyperbaric oxygen therapy and topical oxygen have different routes and probably efficiencies of entry into the wound and their physiology and biochemistry are necessarily different. 3. The application of topical oxygen cannot be recommended outside of a clinical trial at this time based on the volume and quality of scientific supporting evidence available, nor does the Society recommend third party payor reimbursement. 4. Before topical oxygen can be recommended as therapy for non-healing wounds, its application should be subjected to the same intense scientific scrutiny to which systemic hyperbaric oxygen has been held”.

There is insufficient evidence of the effectiveness of hyperbaric oxygen as a treatment for autism. Rossignol (2007) stated that autism is a neurodevelopmental disorder currently affecting as many as 1 out of 166 children in the United States. Numerous studies of autistic individuals have revealed evidence of cerebral hypoperfusion, neuro-inflammation and gastrointestinal inflammation, immune dysregulation, oxidative stress, relative mitochondrial dysfunction, neurotransmitter abnormalities, impaired detoxification of toxins, dysbiosis, and impaired production of porphyrins. Many of these findings have been correlated with core autistic symptoms. For example, cerebral hypoperfusion in autistic children has been correlated with repetitive, self-stimulatory and stereotypical behaviors, and impairments in communication, sensory perception, and social interaction. Hyperbaric oxygen therapy might be able to improve each of these problems in autistic persons. Specifically HBOT has been used with clinical success in several cerebral hypoperfusion conditions and can compensate for decreased blood flow by increasing the oxygen content of plasma and body tissues. Hyperbaric oxygen therapy has been reported to possess strong anti-inflammatory properties and has been shown to improve immune function. There is evidence that oxidative stress can be reduced with HBOT through the upregulation of antioxidant enzymes. Hyperbaric oxygen therapy can also increase the function and production of mitochondria and improve neurotransmitter abnormalities. In addition, HBOT upregulates enzymes that can help with detoxification problems specifically found in autistic children. Dysbiosis is common in autistic children and HBOT can improve this. Impaired production of porphyrins in autistic children might affect the production of heme, and HBOT might help overcome the effects of this problem. Finally, HBOT has been shown to mobilize stem cells from the bone marrow to the systemic circulation. Recent studies in humans have shown that stem cells can enter the brain and form new neurons, astrocytes, and microglia. It is expected that amelioration of these underlying pathophysiological problems through the use of HBOT will lead to improvements in autistic symptoms. Several studies on the use of HBOT in autistic children are currently underway and early results are promising.

An systematic evidence review of hyperbaric oxygen therapy for autism (Moqadem & Pineau, 2007) prepared for AETMIS, a Canadian technology assessment agency, concluded: "In light of its assessment, AETMIS concludes that there is insuffi cient evidence to build a strong case for the efficacy of hyperbaric oxygen therapy in the management of autistic disorders. In these circumstances, a literature watch should be conducted to evaluate the results of the current and future studies. In short, for the management of autism, hyperbaric oxygen therapy should, for now, be considered an experimental treatment modality. Consequently, this treatment should be limited to formal research projects."