[abstract] THE EFFECT OF VARIOUS COMBINATIONS OF PN2 AND PO2 ON CNS OXYGEN TOXICITY

Rubicon Research Repository/Manakin Repository

[abstract] THE EFFECT OF VARIOUS COMBINATIONS OF PN2 AND PO2 ON CNS OXYGEN TOXICITY

Show full item record


Title: [abstract] THE EFFECT OF VARIOUS COMBINATIONS OF PN2 AND PO2 ON CNS OXYGEN TOXICITY
Author: Arieli, R
Abstract: INTRODUCTION: The greatest risk in closed-circuit oxygen diving is of central nervous system (CNS) oxygen toxicity. There are disagreements as to the effect of inert gas, and there are no comprehensive data on the quantitative effect of inert gas. The upper oxygen pressure allowed in diving with oxygen enriched air has been set by NOAA and ANDI at 162 kPa, which is lower than the limit set for pure oxygen diving. The purpose of the study was to quantify the effect of inert gas and oxygen pressure on CNS oxygen toxicity. METHODS: Rats were exposed to 507, 557, 608 and 658 kPa O2, each on a mixture of 100percent, 85percent, 75percent, 60percent, 50percent or 40percent O2 balanced with N2, until the appearance of the first electrical discharge (FED) preceding the clinical convulsions. Decompression was conducted at a PO2 of 300 kPa balanced with N2 using an on-line decompression program. RESULTS: Latency to the FED at a PO2 of 507, 557, 608 and 658 kPa in pure oxygen and at a highest PN2, respectively, was 34 18 min and 12 6 min (PN2 760 kPa), 21 11 min and 15 14 min (PN2 835 kPa), 16 5 min and 9 5 min (PN2 911 kPa) and 14 4 min and 10 6 min (PN2 658 kPa). For most of the rats the latency at a specific PN2, exceeded that obtained for pure oxygen. This occurred mainly at PN2 of 90 kPa, to 400 kPa. DISCUSSION: The general effect of the PN2 is to reduce the latency to CNS oxygen toxicity. However, rats showed prolongation of the latency at a specific PN2, mainly in the region of 200 kPa. It is suggested that rats sensitive to nitrogen narcosis will exhibit prolongation of latency, until HPNS effect that facilitates oxygen toxicity takes over. nitrogen narcosis, HPNS, oxygen toxicity, diving. See J Appl Physiol. 2005 Jan;98(1):144-50. for updated article.
Description: Undersea and Hyperbaric Medical Society, Inc. (http://www.uhms.org )
URI: http://archive.rubicon-foundation.org/1313
Date: 2003

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