[abstract] EARLY PATHOGENESIS AND DETECTION OF DYSBARIC OSTEONECROSIS INDUCED IN SHEEP.

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[abstract] EARLY PATHOGENESIS AND DETECTION OF DYSBARIC OSTEONECROSIS INDUCED IN SHEEP.

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Title: [abstract] EARLY PATHOGENESIS AND DETECTION OF DYSBARIC OSTEONECROSIS INDUCED IN SHEEP.
Author: Lehner, CE; Lin, TF; Lanphier, EH; Wilson, MA; DeSmet, AA; Markel, MD; Dueland, R
Abstract: To evaluate the developmental stages, early diagnostic detection, and potential risk of dysbaric osteonecrosis (DON), DON was induced in sheep long bones with a single hyperbaric exposure. Six female sheep (3-1/2 yr, 66-108 kg) underwent a 24-hour hyperbaric exposure at 2.2-2.4 abs atm and no-stop decompression at 1.6 atm/min. After decompression, clinical signs of limb bends were frequently observed, and Doppler ultrasound indicated numerous circulating venous gas bubbles. Non-invasive diagnostic techniques, roentgenography, scintigraphic bone scans (99m Tc-MDP), and magnetic resonance imaging (MRI), were used to evaluate DON development during the 2 months following decompression. "Cold spots," areas of decreased Tc-MDP uptake that indicate localized ischemia, were observed 2 days after hyperbaric exposure and these later converted to "hot spots." DON lesions presented as "hot spots," areas of increased Tc-MDP uptake that indicate rapid bone formation, as early as 2 weeks after hyperbaric exposure. MRI findings were consistent with the bone scans. Roentgenography detected endosteal thickening and medullary opacities 8 weeks after hyperbaric exposure. At necropsy, gross sections of sheep bones confirmed widespread fatty marrow and bone necrosis. All sheep which underwent hyperbaric exposure developed DON in limbs with persistent limb bends. We propose that DON develops when decompression triggers N2 bubble formation and causes a bone compartment syndrome. The findings suggest that prolonged hyperbaric exposure with rapid decompression is a significant risk factor in DON and that untreated limb bends can lead to DON. (Supported by the UW Sea Grant Institute)
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held June 23-27, 1992. Hyatt Regency Bethesda Hotel, Bethesda, Maryland (http://www.uhms.org)
URI: http://archive.rubicon-foundation.org/6489
Date: 1992

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  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

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