Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Risk assessment of SWEN21 a suggested new dive table for the Swedish armed forces : bubble grades by ultrasonography

Hjelte, Carl LU orcid ; Plogmark, Oskar ; Silvanius, Mårten ; Ekström, Magnus LU orcid and Frånberg, Oskar LU (2023) In Diving and Hyperbaric Medicine 53(4). p.299-305
Abstract

Introduction: To develop the diving capacity in the Swedish armed forces the current air decompression tables are under revision. A new decompression table named SWEN21 has been created to have a projected risk level of 1% for decompression sickness (DCS) at the no stop limits. The aim of this study was to evaluate the safety of SWEN21 through the measurement of venous gas emboli (VGE) in a dive series. Methods: A total 154 dives were conducted by 47 divers in a hyperbaric wet chamber. As a proxy for DCS risk serial VGE measurements by echocardiography were conducted and graded according to the Eftedal-Brubakk scale. Measurements were done every 15 minutes for approximately 2 hours after each dive. Peak VGE grades for the different dive... (More)

Introduction: To develop the diving capacity in the Swedish armed forces the current air decompression tables are under revision. A new decompression table named SWEN21 has been created to have a projected risk level of 1% for decompression sickness (DCS) at the no stop limits. The aim of this study was to evaluate the safety of SWEN21 through the measurement of venous gas emboli (VGE) in a dive series. Methods: A total 154 dives were conducted by 47 divers in a hyperbaric wet chamber. As a proxy for DCS risk serial VGE measurements by echocardiography were conducted and graded according to the Eftedal-Brubakk scale. Measurements were done every 15 minutes for approximately 2 hours after each dive. Peak VGE grades for the different dive profiles were used in a Bayesian approach correlating VGE grade and risk of DCS. Symptoms of DCS were continually monitored. Results: The median (interquartile range) peak VGE grade after limb flexion for a majority of the time-depth combinations, and of SWEN21 as a whole, was 3 (3-4) with the exception of two decompression profiles which resulted in a grade of 3.5 (3-4) and 4 (4-4) respectively. The estimated risk of DCS in the Bayesian model varied between 4.7-11.1%. Three dives (2%) resulted in DCS. All symptoms resolved with hyperbaric oxygen treatment. Conclusions: This evaluation of the SWEN21 decompression table, using bubble formation measured with echocardiography, suggests that the risk of DCS may be higher than the projected 1%.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Decompression, Decompression illness, Decompression tables, Diving, Echocardiography, Risk, Venous gas emboli
in
Diving and Hyperbaric Medicine
volume
53
issue
4
pages
7 pages
publisher
South Pacific Underwater Medicine Society
external identifiers
  • pmid:38091588
  • scopus:85179643629
ISSN
1833-3516
DOI
10.28920/dhm53.4.299-305
language
English
LU publication?
yes
id
eaa22dd4-de7b-419d-abc8-2493f5077627
date added to LUP
2024-01-02 15:10:03
date last changed
2025-05-16 04:47:33
@article{eaa22dd4-de7b-419d-abc8-2493f5077627,
  abstract     = {{<p>Introduction: To develop the diving capacity in the Swedish armed forces the current air decompression tables are under revision. A new decompression table named SWEN21 has been created to have a projected risk level of 1% for decompression sickness (DCS) at the no stop limits. The aim of this study was to evaluate the safety of SWEN21 through the measurement of venous gas emboli (VGE) in a dive series. Methods: A total 154 dives were conducted by 47 divers in a hyperbaric wet chamber. As a proxy for DCS risk serial VGE measurements by echocardiography were conducted and graded according to the Eftedal-Brubakk scale. Measurements were done every 15 minutes for approximately 2 hours after each dive. Peak VGE grades for the different dive profiles were used in a Bayesian approach correlating VGE grade and risk of DCS. Symptoms of DCS were continually monitored. Results: The median (interquartile range) peak VGE grade after limb flexion for a majority of the time-depth combinations, and of SWEN21 as a whole, was 3 (3-4) with the exception of two decompression profiles which resulted in a grade of 3.5 (3-4) and 4 (4-4) respectively. The estimated risk of DCS in the Bayesian model varied between 4.7-11.1%. Three dives (2%) resulted in DCS. All symptoms resolved with hyperbaric oxygen treatment. Conclusions: This evaluation of the SWEN21 decompression table, using bubble formation measured with echocardiography, suggests that the risk of DCS may be higher than the projected 1%.</p>}},
  author       = {{Hjelte, Carl and Plogmark, Oskar and Silvanius, Mårten and Ekström, Magnus and Frånberg, Oskar}},
  issn         = {{1833-3516}},
  keywords     = {{Decompression; Decompression illness; Decompression tables; Diving; Echocardiography; Risk; Venous gas emboli}},
  language     = {{eng}},
  number       = {{4}},
  pages        = {{299--305}},
  publisher    = {{South Pacific Underwater Medicine Society}},
  series       = {{Diving and Hyperbaric Medicine}},
  title        = {{Risk assessment of SWEN21 a suggested new dive table for the Swedish armed forces : bubble grades by ultrasonography}},
  url          = {{http://dx.doi.org/10.28920/dhm53.4.299-305}},
  doi          = {{10.28920/dhm53.4.299-305}},
  volume       = {{53}},
  year         = {{2023}},
}