[abstract] MAGNETIC RESONANCE IMAGING OF CENTRAL NERVOUS SYSTEM DECOMPRESSION SICKNESS IN SHEEP UNDERGOING HYPERBARIC EXPOSURE.

Rubicon Research Repository/Manakin Repository

[abstract] MAGNETIC RESONANCE IMAGING OF CENTRAL NERVOUS SYSTEM DECOMPRESSION SICKNESS IN SHEEP UNDERGOING HYPERBARIC EXPOSURE.

Show full item record


Title: [abstract] MAGNETIC RESONANCE IMAGING OF CENTRAL NERVOUS SYSTEM DECOMPRESSION SICKNESS IN SHEEP UNDERGOING HYPERBARIC EXPOSURE.
Author: Ferrazzano, PA; Sobakin, AS; Hutchinson, E; Lehner, CE; Eldridge, MW
Abstract: BACKGROUND: We have previously demonstrated that oxygen pre-breathing before “drop-out” decompression reduces the risk of decompression sickness (DCS) in the UW sheep model. However, little is known about the incidence and mechanisms of neurological injury in these models, or the effects of decompression strategies on ameliorating neurological DCS. We have undertaken magnetic resonance imaging (MRI) studies to define the incidence and mechanism of CNS injury in a sheep model of decompression sickness. METHODS: Ten adult ewes (91.4 ± 9.2 SD kg) underwent dry chamber air exposure at 60 fsw (2.8 atm abs) for 24 hours, followed by an oxygen (88-92%) pre-breathe for 3-hr before “dropout” decompression at 30 feet/min (0.9 atm/min) to surface. Another four animals (95.6 ± 5.8 SD kg) underwent an identical decompression scenario without oxygen pre-breathing. Six weeks after exposure, animals were sacrificed and brain and spinal cords are fixed in formalin. T2 weighted fast spin-echo imaging and high-resolution 3-dimensional spin-echo imaging were performed on the spinal cords using a high-field strength Varian 4.7 Tesla MRI scanner. RESULTS: Decompression without oxygen pre-breathing resulted in 100% mortality. All the oxygen pre-breathing animals survived. Six animals developed limb bends, with one developing signs of respiratory DCS. Thus far we have found no evidence of focal infarcts in the spinal cords of the oxygen pre-breath group. However, patchy areas of increased T2 signal intensity are seen in white matter. CONCLUSION: Thus far we see no evidence of discreet spinal cord infarction as would occur with arterial gas embolism, suggesting that 3-hr oxygen pre-breathing may reduce the severity of neurological DCS. However, subtle areas of increased signal intensity may represent white matter injury. Our ongoing work will use high-resolution diffusion tensor MRI to further characterize the possible white matter injury. (Funded by NAVSEA, U.S. Navy. We acknowledge the assistance of Dr. Ed Flynn.)
Description: Abstract of the Undersea & Hyperbaric Medical Society 2008 Annual Scientific Meeting June 26-28, 2008 Salt Lake City Marriott Downtown, Salt Lake City, Utah.
URI: http://archive.rubicon-foundation.org/7939
Date: 2008

Files in this item

Files Size Format View
abstract.txt 193bytes 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