Germonpré Peter, Balestra Costantino, Hemelryck Walter, Buzzacott Peter, Lafère Pierre
Aerosp Med Hum Perform. 2017 May 1;88(5):469-475. doi: 10.3357/AMHP.4608.2017.
Divers try to limit risks associated with their sport, for instance by breathing enriched air nitrox (EANx) instead of air. This double blinded, randomized trial was designed to see if the use of EANx could effectively improve cognitive performance while diving.
Eight volunteers performed two no-decompression dry dives breathing air or EANx for 20 min at 0.4 MPa. Cognitive functions were assessed with a computerized test battery, including MathProc and Ptrail. Measurements were taken before the dive, upon arrival and after 15 min at depth, upon surfacing, and at 30 min postdive. After each dive subjects were asked to identify the gas they had just breathed.
Identification of the breathing gas was not possible on subjective assessment alone, while cognitive assessments showed significantly better performance while breathing EANx. Before the dives, breathing air, mean time to complete the task was 1795 ms for MathProc and 1905 ms for Ptrail. When arriving at depth MathProc took 1616 ms on air and 1523 ms on EANx, and Ptrail took 1318 ms on air and and 1356 ms on EANx, followed 15 min later by significant performance inhibition while breathing air during the ascent and the postdive phase, supporting the concept of late dive/postdive impairment.
The results suggest that EANx could protect against decreased neuro-cognitive performance induced by inert gas narcosis. It was not possible for blinded divers to identify which gas they were breathing and differences in postdive fatigue between air and EANx diving deserve further investigation.Germonpré P, Balestra C, Hemelryck W, Buzzacott P, Lafère P. Objective vs. subjective evaluation of cognitive performance during 0.4-MPa dives breathing air or nitrox. Aerosp Med Hum Perform. 2017; 88(5):469-475.
潜水者试图降低与这项运动相关的风险，例如通过呼吸富氧空气氮氧混合气（EANx）而非空气。这项双盲随机试验旨在探究使用EANx是否能在潜水时有效改善认知表现。
八名志愿者在0.4兆帕的压力下进行两次不减压干式潜水，分别呼吸空气或EANx，持续20分钟。使用一套计算机化测试组评估认知功能，包括数学处理和连线测验。在潜水前、到达深度时、在深度停留15分钟后、浮出水面时以及潜水后30分钟进行测量。每次潜水后，要求受试者辨别他们刚刚呼吸的气体。
仅通过主观评估无法辨别呼吸的气体，而认知评估显示呼吸EANx时表现明显更好。潜水前，呼吸空气时，完成数学处理任务的平均时间为1795毫秒，完成连线测验任务的平均时间为1905毫秒。到达深度时，呼吸空气时数学处理任务用时1616毫秒，呼吸EANx时用时1523毫秒；连线测验任务呼吸空气时用时1318毫秒，呼吸EANx时用时1356毫秒，随后在上升和潜水后阶段呼吸空气时出现明显的表现抑制，这支持了潜水后期/潜水后损伤的概念。
结果表明，EANx可以预防惰性气体麻醉引起的神经认知表现下降。蒙眼的潜水者无法辨别他们呼吸的是哪种气体，空气潜水和EANx潜水后疲劳程度的差异值得进一步研究。热尔蒙普雷P、巴莱斯特拉C、赫姆勒里克W、布扎科特P、拉费尔P。在0.4兆帕潜水时呼吸空气或氮氧混合气期间认知表现的客观与主观评估。航空航天医学与人类表现。2017；88(5):469 - 475。
