Psychophysical stress during a 24 h dive: A case study of an older male diver

This case study investigated the psychophysiological stress responses of a diver during and after a 24-h hyperbaric exposure. Comprehensive biomarker analysis revealed relevant changes in oxidative stress parameters and cardiac muscle markers. Notably, a critical time point at 6 h (T2) emerged, characterized by peak oxidative stress and diminished antioxidant capacity, followed by progressive cardiac strain as evidenced by elevated creatine kinase isoenzime (CK-MBm) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels. Despite these physiological challenges, no pathological tissue damage was detected, indicating effective endogenous defense mechanisms. Moreover, no significant psychophysiological symptoms were detected before, during, and after the dive, except for tiredness and insomnia. Cognitive assessments reflected adaptive shifts in response strategies under prolonged stress, emphasizing the importance of monitoring to prevent operational risks. These findings highlight the need to consider dive duration carefully, suggesting that introducing rest intervals or personnel rotation around the critical T2 threshold may mitigate physiological fatigue and optimize performance. This study provides valuable insights into human adaptation to extended hyperbaric conditions and informs safety protocols for commercial and military diving operations.