Lafère Pierre, Balestra Costantino, Hemelryck Walter, Donda Nicola, Sakr Ahmed, Taher Adel, Marroni Sandro, Germonpré Peter
Anesthesiologist and physician in diving and hyperbaric medicine at the Centre for Hyperbaric Oxygen Therapy of the Military Hospital in Brussels and an associate researcher at the Environmental and Occupational Physiology Laboratory of the Haute Ecole Paul-Henri Spaak, Brussels, Centre for Hyperbaric Oxygen Therapy, Military Hospital "Queen Astrid", Rue Bruyn 1, 1120 Brussels, Belgium, Phone: +32-(0)2-264 48 68, Fax: +32-(0)2-264 48 61, E-mail:
Diving Hyperb Med. 2010 Sep;40(3):114-8.
Many divers report less fatigue following dives breathing enriched air nitrox (EANx) compared with breathing air. A reduction of post-dive fatigue with EANx would suggest a pathological origin, possibly the presence of asymptomatic nitrogen bubbles in the body after a dive.
We studied fatigue in 219 healthy divers performing either an air (n = 121) or EANx32 (oxygen 32%, nitrogen 68%; n = 98) dive to 21.2 ± 4 metres' sea water for 43.3 ± 8.6 minutes in tropical open-water conditions. Divers were assessed pre-dive and 30-60 minutes after surfacing using a visual analog scale (VAS) of fatigue and critical flicker fusion frequency (CFFF).
The two groups were comparable in sex ratio, age and diving experience. The change in perceived fatigue level after a single dive was significantly lower when EANx was breathed compared to air dives (VAS; P < 0.001). Compared to pre-dive, CFFF decreased by 6% in the air group (P < 0.01) but increased by 4% in the EANx group (P < 0.05). The post-dive difference between the two groups was highly significant (P < 0.001).
Three hypotheses should be considered to explain the difference in post-dive fatigue and alertness between the air and EANx groups: a nitrogen effect, an oxygen effect and a bubble effect. These involve complex phenomena in the functional modifications of the nervous system in hyperbaric environments according to the type of gas used for the dive, and more research will be required to elucidate them.
许多潜水者报告称,与呼吸空气相比,呼吸富氧空气氮氧混合气(EANx)潜水后疲劳感减轻。使用EANx潜水后疲劳感降低表明存在病理根源,可能是潜水后体内存在无症状氮气泡。
我们研究了219名健康潜水者的疲劳情况,这些潜水者在热带开放水域条件下,分别进行空气潜水(n = 121)或EANx32潜水(氧气32%,氮气68%;n = 98)至21.2 ± 4米海水深度,时长43.3 ± 8.6分钟。潜水前及浮出水面后30 - 60分钟,使用疲劳视觉模拟量表(VAS)和临界闪烁融合频率(CFFF)对潜水者进行评估。
两组在性别比例、年龄和潜水经验方面具有可比性。与空气潜水相比,呼吸EANx潜水后,单次潜水后感知疲劳水平的变化显著更低(VAS;P < 0.001)。与潜水前相比,空气组CFFF下降了6%(P < 0.01),而EANx组CFFF增加了4%(P < 0.05)。两组潜水后的差异高度显著(P < 0.001)。
应考虑三个假说来解释空气组和EANx组潜水后疲劳和警觉性的差异:氮效应、氧效应和气泡效应。这些涉及高压环境下根据潜水所用气体类型神经系统功能改变的复杂现象,需要更多研究来阐明。