Carbogen Inhalation Therapy
This Clinical Policy Bulletin addresses the use of carbogen (5% CO2 / 95% O2) inhalation therapy and states Aetna's coverage stance for various indications; intended for providers submitting claims or prior authorization requests to Aetna.
No material clinical or coverage changes in this revision.
Coverage Criteria for Carbogen Inhalation Therapy
Experimental and Investigational indications
Carbogen inhalation therapy is considered experimental and investigational for the following indications because effectiveness has not been established:
Carbogen inhalation therapy is designated experimental and investigational for multiple indications because peer‑reviewed evidence has not established effectiveness. The policy lists specific conditions for which carbogen is considered investigational, including bladder cancer, central retinal artery occlusion, cervical cancer, head and neck cancers, optic nerve damage/degeneration, prostate cancer, retinal artery occlusion, seizures, stroke, and sudden hearing loss. Corresponding ICD‑10 diagnosis code ranges for these noncovered indications are provided in the policy (e.g., malignancy ranges C00.x–C76.x, retinal vascular occlusions H34.x, optic nerve disorders H46–H47, sudden idiopathic hearing loss H91.20–H91.23, epilepsy/seizures G40.x, and cerebrovascular disease I60–I69).
The policy states there is insufficient evidence to support carbogen inhalation as an effective therapy for retinal artery occlusion; case reports and small series have not established benefit and the document explicitly notes that carbogen has not been proven effective for RAO. For cervical cancer, randomized and nonrandomized studies evaluating carbogen with nicotinamide (CON) did not demonstrate clear improvements in survival or local control, and major reference sources (UpToDate and NCCN) do not list carbogen inhalation as a therapeutic option, so effectiveness for cervical cancer is not established.
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