Chng
A full immersion suit did not cause important thermal stress to escaped submariners
Clinical bottom line:
|
1. There was no practical important difference in the thermal protection between the full immersion and half immersion suits, although the full suit had statistically higher maximum and minimum mean temperatures over 24 hours. |
Citation:
Chng J, Wan MC, Lim CL, Kang WL. A comparison of thermal stress in the submarine escape using immersion half- and full suit in tropical weather operations. Undersea and Hyperbaric Medicine 2010;37(6):447-454.
Lead author's name and fax: Jeremia Chng, chngjeremiah@hotmail.com
Three-part Clinical Question:For submariners who have escaped from a submarine, does the use of a full-configuration immersion suit, compared to a half-configuration suit, result in significant heat stress?
Search Terms: Submarine escape, survival suit, hyperthermia
The Study:
Non-blinded randomised controlled trial with intention-to-treat.
The Study Patients: Volunteer male submariners
Control group (N = 7; 7 analysed): BFA suit - 7 full and 12 half suits.. Ingested temperature sensor capsule. Wetted before being placed in the escape raft for 24 hours.
Experimental group (N = 12; 11 analysed): Beaufort suit - 7 full and 12 half suits. Methods as above.
The Evidence:
Measure |
Full suit |
Half suit |
Difference |
95% CI | ||
|
Mean |
SD |
Mean |
SD | |||
|
Thermal comfort score (-7 very cold to +7 very hot) |
3.2 |
1.1 |
2.7 |
1.1 |
0.5 |
-0.71 to 1.71 |
Non-Event Outcomes |
Time to outcome |
Full suit |
Half suit |
P-value |
|
Mean maximum temperature (full versus half suit) Centigrade |
24 hours |
37.8 |
37.6 |
0.01 |
|
Mean minimum temperature (full versus half suit) Centigrade |
24 hours |
36.1 |
36.0 |
0.03 |
Comments:
1. One volunteer pulled out of the half suit trial due to cold
2. There were no statistically significant differences between the suits from the two different suit manufacturers.
3. There were no differences between the groups with respect to water intake, urine output or weight change.
4. Full immersion suit was safe and did not induce problematic hyperthermia but this trial did not expose the volunteers to direct sunlight or a waiting period of longer than 24 hours.
Mike Bennett, Prince of Wales Hospital m.bennett@unsw.edu.au; Saturday, 28 December 2019
Kill or Update By: December 2024
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