Risk assessment of SWEN21 a suggested new dive table for the Swedish armed forces : bubble grades by ultrasonography
Hjelte, Carl LU ; Plogmark, Oskar ; Silvanius, Mårten ; Ekström, Magnus LU
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)
- author
- Hjelte, Carl
LU
; Plogmark, Oskar
; Silvanius, Mårten
; Ekström, Magnus
LU
and Frånberg, Oskar
LU
- organization
- publishing date
- 2023-12
- 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 Med Soc
- 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
- 2024-04-17 14:26:30
@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 Med Soc}},
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}},
}