Int J Sports Med 2016; 37(14): 1124-1128
DOI: 10.1055/s-0042-110573
Physiology & Biochemistry
© Georg Thieme Verlag KG Stuttgart · New York

Do Environmental Conditions Contribute to Narcosis Onset and Symptom Severity?

P. Lafère
1   Anaesthesia & Reanimation, Hopital de la Cavale-Blanche, Brest, France
C. Balestra
2   Environmental & Occupational Physiology, Haute Ecole Paul Henri Spaak, Auderghem, Belgium
W. Hemelryck
3   Haute Ecole Paul henri spaak, Research Laboratory, Brussels, Belgium
F. Guerrero
4   Université de Bretagne Occidentale, EA4324 – ORPHY, Brest, France
P. Germonpré
5   Military Hospital “Queen Astrid”, Centre for Hyperbaric Oxygen Therapy, Brussels, Belgium
› Author Affiliations
Further Information

Publication History

accepted after revision 03 June 2016

Publication Date:
13 October 2016 (online)


Although many factors contributing to inert gas narcosis onset and severity have been put forward, the available evidence is not particularly strong. Using objective criteria, we have assessed brain impairment associated with narcosis under various environmental diving conditions. 40 volunteers performed a no-decompression dive (33 m for 20 min) either in a dry chamber, a pool or open sea. They were assessed by critical flicker fusion frequency before the dive, upon arriving at depth, 5 min before ascent, on surfacing and 30 min post-dive. Compared to the pre-dive value, the mean value of each measurement was significantly different. An increase of flicker fusion to 105.00±0.69% when arriving at depth is followed by a decrease to 94.05±0.65%. This impairment persists when surfacing and 30 min post-dive, decreasing further to 96.36±0.73% and 96.24±0.73%, respectively. Intragroup comparison failed to demonstrate any statistical difference. When objectively measured narcosis may not be influenced by external factors other than pressure and gas. This might be of importance for training to avoid any over- or underestimation of the severity of narcosis based only on subjective symptoms.

  • References

  • 1 [Anonymous]. Diving physiology. In: Joiner JT. (ed.). NOAA Diving Manual. Diving for Science and Technology. 4th ed. Flagstaff, AZ: Best Publishing Company; 2001: 20-22
  • 2 Abraini JH. Inert gas and raised pressure: evidence that motor decrements are due to pressure per se and cognitive decrements due to narcotic action. Pflugers Arch 1997; 433: 788-791
  • 3 Abraini JH, Kriem B, Balon N, Rostain JC, Risso JJ. Gamma-aminobutyric acid neuropharmacological investigations on narcosis produced by nitrogen, argon, or nitrous oxide. Anesth Analg 2003; 96: 746-749
  • 4 Balestra C, Lafere P, Germonpre P. Persistence of critical flicker fusion frequency impairment after a 33 mfw SCUBA dive: evidence of prolonged nitrogen narcosis?. Eur J Appl Physiol 2012; 112: 4063-4068
  • 5 Bennett PB. Inert gas narcosis and the high pressure nervous syndrome. In: Davis JC. (ed.). Hyperbaric and Undersea Medicine. San Antonio, TX: Medical Seminars Inc; 1981. Lesson No 16
  • 6 Bennett PB, Cross AVC. Alterations in the fusion frequency of flicker correlated with electroencephalogram changes at increased partial pressure of nitrogen. J Physiol (London) 1960; 151: 28-29
  • 7 Bennett PB, Rostain JC. Inert gas narcosis. In: Brubakk A, Neuman TS. eds Bennett and Elliott’s Physiology and Medicine of Diving. 5th ed. London: Saunders; 2003: 300-322
  • 8 Berka C, Levendowski DJ, Lumicao MN, Yau A, Davis G, Zivkovic VT, Olmstead RE, Tremoulet PD, Craven PL. EEG correlates of task engagement and mental workload in vigilance, learning, and memory tasks. Aviat Space Environ Med 2007; 78: B231-B244
  • 9 Colloc'h N, Sopkova-de Oliveira Santos J, Retailleau P, Vivares D, Bonnete F, Langlois d’Estainto B, Gallois B, Brisson A, Risso JJ, Lemaire M, Prange T, Abraini JH. Protein crystallography under xenon and nitrous oxide pressure: comparison with in vivo pharmacology studies and implications for the mechanism of inhaled anesthetic action. Biophys J 2007; 92: 217-224
  • 10 Doolette DJ. Chapter two. Inert gas narcosis. In: Mount T, Dituri J. eds. Exploration and Mixed Gas Diving Encyclopedia. The Tao of Survival Underwater. Miami, FL: IAND Inc./IANTD; 2008: 33-40
  • 11 Fowler B, Ackles KN, Porlier G. Effects of inert gas narcosis on behavior – a critical review. Undersea Biomed Res 1985; 12: 369-402
  • 12 Fowler B, Adams J. Dissociation of the effects of alcohol and amphetamine on inert gas narcosis using reaction time and P300 latency. Aviat Space Environ Med 1993; 64: 493-499
  • 13 Harriss DJ, Atkinson G. Ethical standards in sports and exercise science research: 2016 update. Int J Sports Med 2015; 36: 1121-1124
  • 14 Hecht S, Shlaer SJ. Intermittent stimulation by light: The relation between intensity and critical frequency for different parts of the spectrum. Gen Physiol 1936; 19: 965-977
  • 15 Hemelryck W, Germonpre P, Papadopoulou V, Rozloznik M, Balestra C. Long term effects of recreational SCUBA diving on higher cognitive function. Scand J Med Sci Sports 2014; 24: 928-934
  • 16 Hemelryck W, Rozloznik M, Germonpré P, Balestra C, Lafère P. Functional comparison between critical flicker fusion frequency and simple cognitive tests in subjects breathing air or oxygen in normobaria. Diving Hyperb Med 2013; 43: 138-142
  • 17 Kruse AA. Operational neuroscience: neurophysiological measures in applied environments. Aviat Space Environ Med 2007; 78: B191-B194
  • 18 Lafere P, Lavoute C, Hemelryck W. Nitrogen narcosis. In: Balestra C, Germonpre P. eds. The Science of Diving – Things Your Instructor Never Told You. Saarbrücken: LAP Lambert Academic Publishing; 2014: 183-197
  • 19 Lauridsen MM, Jepsen P, Vilstrup H. Critical flicker frequency and continuous reaction times for the diagnosis of minimal hepatic encephalopathy. A comparative study of 154 patients with liver disease. Metab Brain Dis 2011; 26: 135-139
  • 20 Lavoute C, Weiss M, Risso JJ, Rostain JC. Mechanism of action of nitrogen pressure in controlling striatal dopamine level of freely moving rats is changed by recurrent exposures to nitrogen narcosis. Neurochem Res 2012; 37: 655-664
  • 21 Lavoute C, Weiss M, Rostain JC. Effects of repeated hyperbaric nitrogen-oxygen exposures on the striatal dopamine release and on motor disturbances in rats. Brain Res 2005; 1056: 36-42
  • 22 Lavoute C, Weiss M, Rostain JC. Effects of NMDA administration in the substantia nigra pars compacta on the striatal dopamine release before and after repetitive exposures to nitrogen narcosis in rats. Undersea Hyperb Med 2006; 33: 175-179
  • 23 Lavoute C, Weiss M, Rostain JC. The role of NMDA and GABAA receptors in the inhibiting effect of 3 MPa nitrogen on striatal dopamine level. Brain Res 2007; 1176: 37-44
  • 24 Lavoute C, Weiss M, Rostain JC. Alterations in nigral NMDA and GABAA receptor control of the striatal dopamine level after repetitive exposures to nitrogen narcosis. Exp Neurol 2008; 212: 63-70
  • 25 Levett DZ, Millar IL. Bubble trouble: a review of diving physiology and disease. Postgrad Med J 2008; 84: 571-578
  • 26 Lowry C. Inert gas narcosis. In: Edmons C, Lowry C, Pennefather J, Walker R. eds. Diving and Subaquatic Medicine. 4th ed. London: Hodder Arnold; 2005: 183-193
  • 27 Luczak A, Sobolewski A. Longitudinal changes in critical flicker fusion frequency: an indicator of human workload. Ergonomics 2005; 48: 1770-1792
  • 28 NAVSEA, Air decompression. In: NAVSEA. ed US Navy diving Manual (Revision 6): SS521-AG-PRO-010/0910- LP-106-0957. Washington, D.C.: U. S. Government Printing Office; 2008: 1-84
  • 29 Romero-Gomez M, Cordoba J, Jover R, del Olmo JA, Ramirez M, Rey R, de Madaria E, Montoliu C, Nunez D, Flavia M, Company L, Rodrigo JM, Felipo V. Value of the critical flicker frequency in patients with minimal hepatic encephalopathy. Hepatology 2007; 45: 879-885
  • 30 Rostain JC, Lavoute C, Risso JJ, Vallee N, Weiss M. A review of recent neurochemical data on inert gas narcosis. Undersea Hyperb Med 2011; 38: 49-59
  • 31 Seki K, Hugon M. Critical flicker frequency (CFF) and subjective fatigue during an oxyhelium saturation dive at 62 ATA. Undersea Biomed Res 1976; 3: 235-247
  • 32 Sharma P, Singh S, Sharma BC, Kumar M, Garg H, Kumar A, Sarin SK. Propofol sedation during endoscopy in patients with cirrhosis, and utility of psychometric tests and critical flicker frequency in assessment of recovery from sedation. Endoscopy 2011; 43: 400-405
  • 33 Truszczynski O, Wojtkowiak M, Biernacki M, Kowalczuk K. The effect of hypoxia on the critical flicker fusion threshold in pilots. Int J Occup Med Environ Health 2009; 22: 13-18
  • 34 Vallee N, Rostain JC, Risso JJ. How can an inert gas counterbalance a NMDA-induced glutamate release?. J Appl Physiol 2009; 107: 1951-1958
  • 35 Vallee N, Rostain JC, Risso JJ. A pressurized nitrogen counterbalance to cortical glutamatergic pathway stimulation. Neurochem Res 2010; 35: 718-726