[abstract] COMPARISON OF DYSBARIC OSTEONECROSIS SEVERITY IN THE UW SHEEP MODEL AFTER A 24 HOUR DIVE AT 60 FSW FOLLOWED BY EITHER A 15-MIN, 1-H, 2-H OXYGEN PRE-BREATHES BEFORE DROPOUT DECOMPRESSION.

Rubicon Research Repository/Manakin Repository

[abstract] COMPARISON OF DYSBARIC OSTEONECROSIS SEVERITY IN THE UW SHEEP MODEL AFTER A 24 HOUR DIVE AT 60 FSW FOLLOWED BY EITHER A 15-MIN, 1-H, 2-H OXYGEN PRE-BREATHES BEFORE DROPOUT DECOMPRESSION.

Show full item record


Title: [abstract] COMPARISON OF DYSBARIC OSTEONECROSIS SEVERITY IN THE UW SHEEP MODEL AFTER A 24 HOUR DIVE AT 60 FSW FOLLOWED BY EITHER A 15-MIN, 1-H, 2-H OXYGEN PRE-BREATHES BEFORE DROPOUT DECOMPRESSION.
Author: Sobakin, AS; Lehner, CE; Dueland, RT; Wilson, MA; Gendron-Fitzpatrick, AP; Abraham, JL
Abstract: BACKGROUND: After a provocative dive, bubble formation in fatty long bone marrow may lead to a bone compartment syndrome with bone and marrow ischemia and necrosis. We evaluated oxygen pre-breathes (15-min, 1-h, and 2-h) to determine which would be most likely to provoke dysbaric osteonecrosis (DON) and where DON would occur. MATERIALS AND METHODS: Twelve adult female sheep (99 ± 14 kg SD) underwent dry chamber air exposure at 60 fsw (2.79 atm abs) for 24 h followed by oxygen (88-92%) pre-breathe (15-min, 1-h, and 2-h) before “dropout” decompression 30 fsw/min (0.91 atm/min). One month later, 99mTc-methylene diphosphonate (MDP) bone scans of radii and tibiae were used to detect “hot spots” of remodeling DON lesions. Alizarin complexone fluorochrome was injected IV to visualize sites of DON repair. Six weeks post “dropout” decompression, sheep underwent necropsy to observe DON pathology. Images of long bone gross pathology were taken. Using Scion Image software (Scion Corporation, Frederick, MD), we mapped the areal extent of alizarin complexone deposition as the index of DON severity. DON severity was compared by ANOVA. RESULTS: Alizarin complexone deposition was greater in sheep experiencing 15-min O2 pre-breathe dives than 1-h O2 pre-breathe dives (P<0.05), and sheep DCS incidence was lowest in the 2- h oxygen pre-breathe group. Proximal radii accumulated more alizarin complexone in the 15-min O2 pre-breathe group than in the 1-h group (P<0.05). The proximal tibia appeared most affected in the 2-h O2 pre-breathe dive group (P<0.05). CONCLUSIONS: Brief 15-min O2 pre-breathe dives show greater DON severity than 1-h and 2-h O2 dives. In humans, DON often may trigger secondary osteoarthritis. These findings indicate that even a 2-h O2 pre-breathing did not prevent DON in decompressed sheep, but enabled “dropout” survival. (Research was funded by NAVSEA, U.S. Navy. We acknowledge the assistance Dr. Ed Flynn.)
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held June 14-16, 2007. Ritz-Carlton Kapalua Maui, Hawaii (http:www.uhms.org)
URI: http://archive.rubicon-foundation.org/5147
Date: 2007

Files in this item

Files Size Format View
abstract.txt 259bytes Text file View/Open

This item appears in the following Collection(s)

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

Show full item record

Browse

My Account