Beynon Christopher, Sun Li, Marti Hugo H, Heiland Sabine, Veltkamp Roland
Department of Neurology, University of Heidelberg, Germany.
Neurosci Lett. 2007 Oct 2;425(3):141-5. doi: 10.1016/j.neulet.2007.07.009. Epub 2007 Aug 1.
Hyperbaric (HBO) and normobaric (NBO) oxygen therapy have been shown to be neuroprotective in focal cerebral ischemia. In previous comparative studies, NBO appeared to be less effective than HBO. However, the experimental protocols did not account for important advantages of NBO in the clinical setting such as earlier initiation and prolonged administration. Therefore, we compared the effects of early prolonged NBO to delayed HBO on infarct size and functional outcome. We also examined whether combining NBO and HBO is of additional benefit. Wistar rats underwent filament-induced middle cerebral artery occlusion (MCAO) for 150 min. Animals breathed either air, 100% O(2) at ambient pressure (NBO; initiated 30 min after MCAO) 100% O(2) at 3 atm absolute (HBO; initiated 90 min after MCAO), or a sequence of NBO and HBO. Infarct volumes and neurological outcome (Garcia score) were examined 7d after MCAO. HBO (174+/-65 mm(3)) significantly reduced mean infarct volume by 31% compared to air (251+/-59 mm(3)) and by 23% compared to NBO treated animals (225+/-63 mm(3)). In contrast, NBO failed to decrease infarct volume significantly. Treatment with NBO+HBO (185+/-101 mm(3)) added no additional benefit to HBO alone. Neurological deficit was significantly smaller in HBO treated animals (Garcia score: 13.3+/-1.2) than in animals treated with air (12.1+/-1.4), but did not differ significantly from NBO (12.4+/-0.9) and NBO+HBO (12.8+/-1.1). In conclusion, HBO is a more effective therapy than NBO in transient experimental ischemia even when accounting for delayed treatment-onset of HBO. The combination of NBO and HBO results in no additional benefit.
高压氧（HBO）和常压氧（NBO）疗法已被证明对局灶性脑缺血具有神经保护作用。在以往的比较研究中，NBO似乎不如HBO有效。然而，实验方案并未考虑到NBO在临床环境中的重要优势，如更早开始治疗和更长时间的给药。因此，我们比较了早期长时间NBO与延迟HBO对梗死体积和功能结局的影响。我们还研究了联合使用NBO和HBO是否具有额外的益处。Wistar大鼠接受丝线诱导的大脑中动脉闭塞（MCAO）150分钟。动物分别呼吸空气、常压下的100%氧气（NBO；MCAO后30分钟开始）、3个绝对大气压下的100%氧气（HBO；MCAO后90分钟开始），或NBO和HBO的联合序列。MCAO后7天检查梗死体积和神经功能结局（加西亚评分）。与空气组（251±59立方毫米）相比，HBO（174±65立方毫米）使平均梗死体积显著减少31%，与NBO治疗组动物（225±63立方毫米）相比减少23%。相比之下，NBO未能显著降低梗死体积。NBO+HBO治疗组（185±101立方毫米）并未比单独使用HBO带来额外益处。HBO治疗组动物的神经功能缺损（加西亚评分：13.3±1.2）明显小于空气治疗组动物（12.1±1.4），但与NBO组（12.4±0.9）和NBO+HBO组（12.8±1.1）相比无显著差异。总之，在短暂性实验性缺血中，即使考虑到HBO治疗开始延迟，HBO仍是比NBO更有效的治疗方法。NBO和HBO联合使用并未带来额外益处。
