Central Retina Arterial Occlusion (CRAO)
Central retina arterial occlusion (CRAO) is a blockage from a blood clot or fat deposit occurring in one of the small arteries which carry blood to the retina, the layer of tissue in the back of the eye that senses light. CRAO affects the entire eye causing sudden blurring or loss of vision due to the lack of oxygen.
To date, hyperbaric oxygen therapy is the only treatment option for CRAO with favorable results. It should be treated within 8-24 hours to achieve optimal outcomes. Some visual acuity (light/dark) may be recovered for up to two weeks.
Referral Protocol: Immediately, preferably within 8 hours but no more than 24 hours to achieve an optimal outcome, but refer up to two weeks for a chance to regain some visual acuity (light/dark):
-Hyperbaric oxygen therapy must be initiated before the retinal tissue is irreparably damaged. Adequate partial pressure of oxygen must be maintained to keep the retina viable until circulation is restored.
The degree of occlusion of the blocked vessel may vary accounting for why some patients respond to oxygen at lower partial pressures more than others. Some patients may not respond to oxygen therapy even when treated promptly if the level of occlusion is at the ophthalmic artery because the blood supply to the posterior ciliary vessels is blocked as well and there is no alternate choroidal blood supply to provide oxygenation of the inner layer of the retina
Hyperbaric oxygen therapy delivered at HyOx increases the chance of reversing the loss of vision IF retinal tissue isn’t irreparably damaged with cell death and necrosis in the inner layers of the retinal artery, and to supply oxygen to the retinal tissue to maintain its life while blood flow is restored (either medically assisted or spontaneous).
Crush Injury, Compartment Syndrome (acute traumatic peripheral ischemias)
A crush injury occurs when a body part is crushed or trapped for a period of time. The crushing event injures the blood vessels in the area so that when the body part is freed and no longer crushed, there is not adequate blood flow for healing.
Compartment syndrome happens when bones or muscles, contained in “compartments” divided by fibrous tissue in the extremities, are injured causing edema or swelling in a compartment. In severe cases, the blood vessels can collapse, cutting off flow to the area and impairing healing.
Referral Protocol: Within four to six hours of crush injury
Hyperbaric oxygen therapy delivered at HyOx works to decrease swelling, provide oxygen to tissues with inadequate blood supply, and build new blood vessels.
Brown Recluse Spider Bites
Closets, attics, boxes, and basements are favorite urban settings for the brown recluse or fiddle back spider. Deemed more of a public health menace than the black widow or any other arachnid, the brown recluse is surprisingly non-aggressive and won’t attack unless threatened.
At first, a person who has been bitten by a brown recluse may only notice irritation on the skin. After two to eight hours, the affected area becomes a papule (a small, raised, solid swelling, typically inflamed but not producing pus). The papule turns white from the localized thrombosis, vasoconstriction, and infarction of the tissue.
After time, the skin lesion becomes more evident with the development of a hemorrhagic vesicle. Subsequently, the vesicle will rupture and form a black crust. As the crust sloughs, it has a necrotic ulcer that can extend through the subcutaneous fat and expose muscles and fascial planes. These disfiguring ulcers can be up to 25 cm. Other symptoms include fever, renal failure, chills, rash, nausea, and hemolytic anemia.
Hyperbaric oxygen therapy delivered at HyOx works to improve wound healing, along with a course of antibiotics.