Monica Rocco1, P Pelaia2, P Di Benedetto3, G Conte4, L Maggi5, S Fiorelli6, M Mercieri6, C Balestra7, R A De Blasi6. 1. Department of Surgical and Medical Science and Translational Medicine, Anesthesia and Intensive Care, Sapienza University, Rome, Italy. monica.rocco@uniroma1.it. 2. Department of Biomedical Sciences and Public Health, Anesthesia and Intensive Care, Università Politecnica delle Marche Torrette, Ancona, Italy. 3. Azienda Ospedaliero, Universitaria Sant'Andrea, Rome, Italy. 4. Department of Informatics Engineering, University Politecnica delle Marche, Ancona, Italy. 5. Anesthesia and Intensive Care, Università Campus Biomedico, Rome, Italy. 6. Department of Surgical and Medical Science and Translational Medicine, Anesthesia and Intensive Care, Sapienza University, Rome, Italy. 7. Environmental, Occupational and Ageing (Integrative) Physiology Lab, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium.
Abstract
PURPOSE: Underwater divers face several potential neurological hazards when breathing compressed gas mixtures including nitrogen narcosis which can impact diver's safety. Various human studies have clearly demonstrated brain impairment due to nitrogen narcosis in divers at 4 ATA using critical flicker fusion frequency (CFFF) as a cortical performance indicator. However, recently some authors have proposed a probable adaptive phenomenon during repetitive exposure to high nitrogen pressure in rats, where they found a reversal effect on dopamine release. METHODS: Sixty experienced divers breathing Air, Trimix or Heliox, were studied during an open water dive to a depth of 6 ATA with a square profile testing CFFF measurement before (T0), during the dive upon arriving at the bottom (6 ATA) (T1), 20 min of bottom time (T2), and at 5 m (1.5 ATA) (T3). RESULTS: CFFF results showed a slight increase in alertness and arousal during the deep dive regardless of the gas mixture breathed. The percent change in CFFF values at T1 and T2 differed among the three groups being lower in the air group than in the other groups. All CFFF values returned to basal values 5 min before the final ascent at 5 m (T3), but the Trimix measurements were still slightly better than those at T0. CONCLUSIONS: Our results highlight that nitrogen and oxygen alone and in combination can produce neuronal excitability or depression in a dose-related response.
PURPOSE: Underwater divers face several potential neurological hazards when breathing compressed gas mixtures including nitrogennarcosis which can impact diver's safety. Various human studies have clearly demonstrated brain impairment due to nitrogennarcosis in divers at 4 ATA using critical flicker fusion frequency (CFFF) as a cortical performance indicator. However, recently some authors have proposed a probable adaptive phenomenon during repetitive exposure to high nitrogen pressure in rats, where they found a reversal effect on dopamine release. METHODS: Sixty experienced divers breathing Air, Trimix or Heliox, were studied during an open water dive to a depth of 6 ATA with a square profile testing CFFF measurement before (T0), during the dive upon arriving at the bottom (6 ATA) (T1), 20 min of bottom time (T2), and at 5 m (1.5 ATA) (T3). RESULTS: CFFF results showed a slight increase in alertness and arousal during the deep dive regardless of the gas mixture breathed. The percent change in CFFF values at T1 and T2 differed among the three groups being lower in the air group than in the other groups. All CFFF values returned to basal values 5 min before the final ascent at 5 m (T3), but the Trimix measurements were still slightly better than those at T0. CONCLUSIONS: Our results highlight that nitrogen and oxygen alone and in combination can produce neuronal excitability or depression in a dose-related response.
Authors: Pierre Lafère; Walter Hemelryck; Peter Germonpré; Lyubisa Matity; François Guerrero; Costantino Balestra Journal: Diving Hyperb Med Date: 2019-06-30 Impact factor: 0.887
Authors: Xavier Ce Vrijdag; Hanna van Waart; Jamie W Sleigh; Costantino Balestra; Simon J Mitchell Journal: Diving Hyperb Med Date: 2020-12-20 Impact factor: 0.887
Authors: D De Bels; C Pierrakos; A Bruneteau; F Reul; Q Crevecoeur; N Marrone; D Vissenaeken; G Borgers; C Balestra; P M Honoré; S Theunissen Journal: Front Physiol Date: 2019-06-26 Impact factor: 4.566
Authors: Monica Rocco; Luigi Maggi; Chiara Loffredo; Massimiliano Pelli; Pia Di Benedetto; Silvia Fiorelli; Maurizio Simmaco; Roberto Alberto De Blasi Journal: Diving Hyperb Med Date: 2021-06-30 Impact factor: 1.228