男性在0.25兆帕压力下进行90分钟的多次吸氧后肺功能情况。

Pulmonary function in men after repeated sessions of oxygen breathing at 0.25 MPa for 90 min.

作者信息

Mialon P, Barthélémy L, Michaud A, Lacour J M

机构信息

Pulmonary Function Test Unit, Department of Anesthesiology, Brest, France.

出版信息

Aviat Space Environ Med. 2001 Mar;72(3):215-8.

PMID:11277287

Abstract

HYPOTHESIS

We wanted to evaluate the pulmonary effects of discontinuous oxygen breathing (15 min O2, 2 min air breaks, 15:2), at 0.25 MPa once a day for 90 min O2 (6 sequences) over 10 d. This sequence, which has never been evaluated, is currently used in our hyperbaric therapy center.

METHODS

Clinical and functional pulmonary status (questionnaire, spirometry, flow/volume loop, pulmonary diffusing capacity for carbon monoxide) was assessed in 10 non-smoking healthy volunteers after one exposure at 0.25 MPa consisting of 90 min of discontinuous oxygen breathing (15:2) and in 10 non-smoking patients who received a hyperbaric treatment consisting of 90 min of the same discontinuous O2 breathing (15:2) once a day over 10 d. The patients received daily intravenous methylprednisolone (1 mg x kg(-1)) and nicergoline (60 mg).

RESULTS

There were no respiratory symptoms in either group. As expected, for a single exposure of that duration, lung function did not change in volunteers; however, a significant decrease in maximal expiratory flows (MEF) at 50 (-15%) and 25% (-33%) of forced vital capacity (p < 0.05) without change in forced vital capacity (FVC) appeared in patients treated over 10 d.

CONCLUSION

Repetition of the 15:2 oxygen breathing sequence for 90 min once a day over 10 d led to greater flow limitation in peripheral airways than reported after continuous oxygen breathing of 210 min at 0.3 MPa which showed a 7% decrement in MEF50 and a 12% decrement in MEF25. No studies reporting these indexes were found in the 0.2-0.25 MPa range. Similar decrements in MEF50 and MEF25 with steady FVC have been reported after 14 d of daily hyperbaric therapy (0.24 MPa) with 30:5 sequence (-9% and -13%, respectively), 80% of the patients were symptom free. Similarily, our patients were all symptom free and remained so 1 yr after the study, hence, this toxicity is of weak clinical significance in subjects free of inflammatory lung diseases. HBO therapy, though safe, is not totally without effect on the lung.

摘要

假设

我们想要评估间断吸氧（15分钟氧气，2分钟空气间歇，即15:2模式）的肺部效应，每天一次，在0.25兆帕压力下进行90分钟吸氧（共6个序列），持续10天。这种序列此前从未被评估过，目前在我们的高压氧治疗中心被使用。

方法

对10名不吸烟的健康志愿者和10名不吸烟的患者进行了评估。健康志愿者在0.25兆帕压力下接受一次90分钟的间断吸氧（15:2模式）暴露后，评估其临床和肺功能状态（通过问卷调查、肺活量测定、流量/容积环、一氧化碳肺弥散量）；10名患者接受为期10天的高压氧治疗，每天一次，每次90分钟相同的间断吸氧（15:2模式）。患者每天接受静脉注射甲泼尼龙（1毫克/千克）和尼麦角林（60毫克）。

结果

两组均未出现呼吸道症状。正如预期的那样，对于单次该时长的暴露，志愿者的肺功能没有变化；然而，在接受10天治疗的患者中，用力肺活量50%（下降15%）和25%（下降33%）时的最大呼气流量（MEF）显著降低（p<0.05），而用力肺活量（FVC）没有变化。

结论

每天一次，持续10天，每次90分钟重复15:2的吸氧序列，导致外周气道的气流受限比在0.3兆帕压力下持续吸氧210分钟后报告的情况更严重，后者显示MEF50下降7%，MEF25下降12%。在0.2 - 0.25兆帕范围内未发现报告这些指标的研究。在每天进行高压氧治疗（0.24兆帕），采用30:5序列，持续14天后，也报告了MEF50和MEF25有类似下降（分别为-9%和-13%），80%的患者无症状。同样，我们的患者均无症状，并且在研究后1年仍保持无症状，因此，这种毒性在无炎性肺部疾病的受试者中临床意义较弱。高压氧治疗虽然安全，但并非对肺部完全没有影响。