Submerged oxygen breathing produced a distinctive pattern of volatile organic compounds compared to air breathing at 1.9 ATA.

1. Significant increases in methyl alkanes and other volatile organic compounds after oxygen breathing at 9msw compared to air breathing.

2. Oxygen diving produced a distinguishable pattern, however there is no known clinical significance.

Citation/s:
1. van Ooij PJAM, van Hulst RA, Kulik W, Brinkman P, Houtkooper A, Sterk PJ. Hyperbaric oxygen diving affects exhaled molecular profiles in men. Respiratory Physiology and Neurobiology 2014; 198:20-24.

Lead author's name and fax: van Ooij pjam.vanooij.01@mindef.nl
Three-part Clinical Question: For immersed divers does the pattern of volatile organic compounds exhaled change when breathing 100% oxygen at 1.9 ATA compared to air breathing at 1.9 ATA?
Search Terms: Exhaled air; volatile organic compounds; hyperbaric oxygen

The Study: Double-blinded concealed randomised crossover trial with intention-to-treat.

The Study Patients: Professional Naval divers

Control group (N = 10 dives; 9 analysed): A single dive to 9msw (1.9ATA) for 60 minutes lying prone, inactive and breathing air.
Experimental group (N = 10 dives; 10 analysed): As above but breathing 100% oxygen.

The Evidence:

Change in concentration of volatile organic compounds before and after dive
Time to outcome
Air dive
Oxygen dive
P-value
2-Methyloctacosane (MOC) (Area under curve and IQR)
4 hrs
-13.45 (13.29)
14.60 (1.24)
0.017
Hexane 2,4-dimethyl- (DMH) (Area under curve and IQR)
4 hrs
-2.03 (8.97)
0.12 (15.58)
0.028
Comments:
1. Compounds found increased after oxygen suggest some lipid peroxidation in cell membranes or an inflammatory process.
2. These findings may represent an adaptation to hyperoxia.
3. The delay of sampling to four hours after exposure may have altered the pattern of VOCs compared to other investigations.


Appraised by: Mike Bennett, Prince of Wales Hospital; Monday, 4 December 2017
Email: m.bennett@unsw.edu.au

Kill or Update By: December 2021




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