[abstract] USE OF A DEEP (15M) AND SHALLOW (6M) STOP FOLLOWING 25 METER NO-DECOMPRESSION DIVES REDUCES DECOMPRESSION STRESS (AS OBSERVED BY DOPPLER-DETECTABLE BUBBLES) WHEN COMPARED TO EITHER A DIRECT ASCENT, OR DIRECT ASCENT WITH ONLY A SHALLOW STOP.

Rubicon Research Repository/Manakin Repository

[abstract] USE OF A DEEP (15M) AND SHALLOW (6M) STOP FOLLOWING 25 METER NO-DECOMPRESSION DIVES REDUCES DECOMPRESSION STRESS (AS OBSERVED BY DOPPLER-DETECTABLE BUBBLES) WHEN COMPARED TO EITHER A DIRECT ASCENT, OR DIRECT ASCENT WITH ONLY A SHALLOW STOP.

Show full item record


Title: [abstract] USE OF A DEEP (15M) AND SHALLOW (6M) STOP FOLLOWING 25 METER NO-DECOMPRESSION DIVES REDUCES DECOMPRESSION STRESS (AS OBSERVED BY DOPPLER-DETECTABLE BUBBLES) WHEN COMPARED TO EITHER A DIRECT ASCENT, OR DIRECT ASCENT WITH ONLY A SHALLOW STOP.
Author: Marroni, A; Bennett, PB; Cronje, FJ; Balestra, C; Cali-Corleo, R; Germonpre, P; Pieri, M; Bonuccelli, C
Abstract: INTRODUCTION: The incidence of neurological DCS has changed very little notwithstanding modifications to decompression algorithms and dive computers. The efficacy of stage vs. linear decompression was already demonstrated in 1908 by Haldane. Yet changes to decompression ratios have diminished the importance of fast tissues as leading tissues and the need for deep stops during decompression. Most no-decompression dives follow a linear rate of decompression to the surface. METHODS: This study examined the effect of different ascent rates and decompression stops on the Doppler Bubble Score Indexes (BSI) of 22 volunteer divers. Two, consecutive, 25 m (82 fsw) dives were performed for 25 and 20 minutes respectively. The dives were separated by a 3h30 surface interval and each dive series was separated by at least 7 days. Following these dives, the divers ascended according to 8 different protocols: Ascent rates of 3, 10 and 18 (10, 33 and 60 fsw) m/min were combined with no stops, only shallow stops (6 m; 20 fsw), or deep and shallow stops (15 m; 50 fsw and 6 m; 20 fsw). RESULTS: No DCI were reported. The highest precordial BSI - using both Spencer Scale (SS) and Extended Spencer Scales (ESS) for each repetitive dive sequence were respectively 8.78/9.97 (ESS/SS) in no stop, linear ascents vs. 1.79/2.50 (ESS/SS) for the 10-m/min ascent rate with both deep and shallow stops. CONCLUSIONS: The introduction of a 15m (50 fsw) deep stop appears to significantly decrease the degree of decompression stress as observed by Doppler-detectable bubbles and calculated gas tension loading in the 5 and 10 minute tissues. These tissue compartments reflect gas exchange in the spinal cord, and the authors are of the opinion that the addition of a deep stop (15m; 50 fsw) may therefore potentially reduce the incidence of spinal cord decompression sickness in this type of diving.
Description: Undersea and Hyperbaric Medical Society, Inc. (http://www.uhms.org )
URI: http://archive.rubicon-foundation.org/1520
Date: 2004

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