[abstract] INERT GAS COMPOSITION OF INTRAVASCULAR BUBBLES IN GUINEA PIGS FOLLOWING DECOMPRESSION FROM EXPERIMENTAL DIVES.

Rubicon Research Repository/Manakin Repository

[abstract] INERT GAS COMPOSITION OF INTRAVASCULAR BUBBLES IN GUINEA PIGS FOLLOWING DECOMPRESSION FROM EXPERIMENTAL DIVES.

Show full item record


Title: [abstract] INERT GAS COMPOSITION OF INTRAVASCULAR BUBBLES IN GUINEA PIGS FOLLOWING DECOMPRESSION FROM EXPERIMENTAL DIVES.
Author: MacCallum, ME; Lillo, RS; Caldwell, JM
Abstract: These experiments examined the effect of the inert gas mixture breathed during a dive on the composition of intravascular bubbles following decompression. Unanesthetized guinea pigs were compressed to depths ranging from 250 to 300 fsw with air, HeO2 (21% 02), or one of two different N2-He-02 mixtures (21% O2), Animals were held at depth for one hour, and then decompressed slowly (1 fsw/sec) or rapidly <15 sec) to 5 fsw. Physiological variables (arterial blood pressure, heart rate, and ventilation) were then monitored for signs of decompression sickness (DCS). Usually severe DCS developed and death quickly occurred. Immediately upon death, blood samples containing bubbles were withdrawn in a glass syringe from an indwelling catheter in either the right atrium or the inferior vena cava. Gas samples (25 microl) were then taken from the bubbles in the blood using a gastight syringe and analyzed for N2, He, CO2, and O2, via gas chromatography. Bubbles from all dives were found to contain 5-7% CO2, 2-5% O2, with the balance being inert gas. Animals dived on He-02 showed only trace amounts <2%) of N2 in bubble samples after slow decompression. Results from both trimix dives following slow decompression revealed that bubbles contained substantially more N2 than He (on average 1.9 times more) compared to the breathing mixture. This N2 to He ratio dropped on average to 1.6 following rapid decompression. This change in inert gas composition from breathing gas to bubble gas may reflect differences between N2 and He in tissue solubility and gas exchange rates. (Supported by NMRDC Work Unit No. M0099.01A.1002) (UHMS SPON: J Clarke)
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held 6-11 June 1989. Hawaiian Regent Hotel, Honolulu, Hawaii, USA (http://www.uhms.org)
URI: http://archive.rubicon-foundation.org/6582
Date: 1989

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