Research of diver body functions’ state with different resistance to the toxic oxygen effect: prospective cohort study
Authors: Zverev D. P. , Israfilov Z. M. , Myasnikov A. A. , Shitov A. Yu. , Chernov V. I. 
Published: October 2022

INTRODUCTION: The relevance of this issue is due to the fact that nowadays there is no common understanding of the influence degree of high partial oxygen pressures on a body functions’ state, depending on individual resistance.OBJECTIVE: Research the state of the functions of the central nervous, cardiovascular and respiratory systems among people with different resistance to the toxic oxygen effect in the descending and the nearest post-descending period.MATERIALS AND METHODS: There was an examination of 11 divers aged 23 to 43 (the average age is 35.5±6.5 years) in conditions of a simulated descent in a pressure chamber to the depth of 15 m (0.25 MPa) while breathing oxygen, and also during 3 days after its termination. Statistic: Software SPSS, v. 20.0 (IBM) was applied for statistical processing of the results.RESULTS: Baseline heart rate (HR) in the low toxic oxygen resistant group (group I) is 10% (р<0.05) higher than the subjects, recognized as resistant (group II). To 60 minutes oxygen breathing (pO2=0.25 MPa) there is a decrease in heart rate (HR) by 12.5% in group I and 11% in group II, comparing the baseline (р><0.05). An increase of diastolic pressure level in group II is 10.5% to 15 min descent and 18% to 45 min, comparing the baseline (р><0.05). In group I the pulse pressure level reduced by 18%, comparing the baseline (р><0.05). Gencha test results after descent rose by 55% in group I and by 62.5% in group II, comparing the baseline (р�0.05), and indicators higher than initial remained for 3 days more. In group I there was reduction of information processing speed by a visual analyzer of 16% (from 0.788 to 0.661 b/sec) and increase in escape latency of a simple visual-motor reaction by 11.7%, comparing the baseline (р><0.05). DISCUSSION: Divers with different resistance to the toxic oxygen effect experience multidirectional reaction of the central nervous, cardiovascular and respiratory systems. Individuals, resistant to the toxic oxygen effect, are characterized by more active inclusion of counteraction mechanisms to hyperoxia and significant reduction in the level of adaptation reserves and the efficiency of the cardiovascular system. People with low resistance experience a decrease in the functionality level of the central nervous system. CONCLUSION: The results obtained have a basis for admitting the application of the method of determining individual body resistance to the toxic oxygen effect and tests with increasing dosed physical activity in order to estimate adaptation reserves and efficiency. >< 0.05) higher than the subjects, recognized as resistant (group II). To 60 minutes oxygen breathing (pO2=0.25 MPa) there is a decrease in heart rate (HR) by 12.5% in group I and 11% in group II, comparing the baseline (р< 0.05). An increase of diastolic pressure level in group II is 10.5% to 15 min descent and 18% to 45 min, comparing the baseline (р< 0.05). In group I the pulse pressure level reduced by 18%, comparing the baseline (р< 0.05). Gencha test results after descent rose by 55% in group I and by 62.5% in group II, comparing the baseline (р 0.05), and indicators higher than initial remained for 3 days more. In group I there was reduction of information processing speed by a visual analyzer of 16% (from 0.788 to 0.661 b/sec) and increase in escape latency of a simple visual-motor reaction by 11.7%, comparing the baseline (р< 0.05).DISCUSSION: Divers with different resistance to the toxic oxygen effect experience multidirectional reaction of the central nervous, cardiovascular and respiratory systems. Individuals, resistant to the toxic oxygen effect, are characterized by more active inclusion of counteraction mechanisms to hyperoxia and significant reduction in the level of adaptation reserves and the efficiency of the cardiovascular system. People with low resistance experience a decrease in the functionality level of the central nervous system.CONCLUSION: The results obtained have a basis for admitting the application of the method of determining individual body resistance to the toxic oxygen effect and tests with increasing dosed physical activity in order to estimate adaptation reserves and efficiency.