Lou Min, Eschenfelder Christoph C, Herdegen Thomas, Brecht Stephan, Deuschl Günther
Department of Neurology, Christian-Albrechts University of Kiel, Kiel, Germany.
Stroke. 2004 Feb;35(2):578-83. doi: 10.1161/01.STR.0000111599.77426.A0. Epub 2004 Jan 8.
Hyperbaric oxygenation (HBO) is an attractive procedure that has been used frequently in cerebral ischemia. However, depending on the model of cerebral ischemia and HBO protocol, different and conflicting results were obtained in the past. This study was undertaken to reevaluate the effects of single administration of HBO in 2 models of acute cerebral ischemia: transient or permanent focal ischemia in rats. A comparison of the 2 ischemia models was undertaken to search for a putative therapeutic window.
The intraluminal middle cerebral artery occlusion model (MCAO) was used. The effect of single HBO therapy (3 atm absolute, 60 minutes) on transient or permanent focal ischemia, when applied at different times (3, 6, or 12 hours) after MCAO, was investigated; infarct volume and neurological deficits were assessed at 24 hours and up to 7 days.
HBO had neuroprotective effects on transient MCAO when HBO was initiated within the first 6 hours, while it aggravated the ischemic injury histologically and clinically when initiated 12 hours after MCAO. In permanent MCAO, HBO did not reduce tissue damage regardless of the timing of therapy.
HBO is highly efficient in reducing infarct volume and improving neurobehavioral outcome in transient MCAO within the first 6 hours. HBO at later time points (>or=12 hours) is harmful by increasing infarct volume. In permanent MCAO, HBO failed to improve infarct volume and clinical outcome.
高压氧治疗（HBO）是一种颇具吸引力的治疗方法，已被广泛应用于脑缺血治疗。然而，既往研究依据不同的脑缺血模型及HBO治疗方案，得出了各异且相互矛盾的结果。本研究旨在重新评估单次HBO治疗对两种急性脑缺血模型（大鼠短暂性或永久性局灶性缺血）的影响。同时对这两种缺血模型进行比较，以探寻可能的治疗窗。
采用大脑中动脉线栓法闭塞模型（MCAO）。研究单次HBO治疗（绝对压3个大气压，60分钟）在MCAO术后不同时间点（3、6或12小时）应用于短暂性或永久性局灶性缺血时的效果；于术后24小时及直至7天评估梗死体积和神经功能缺损情况。
在短暂性MCAO模型中，若在发病后6小时内开始HBO治疗，其具有神经保护作用；而若在MCAO术后12小时开始治疗，则在组织学和临床方面均会加重缺血损伤。在永久性MCAO模型中，无论治疗时机如何，HBO均不能减轻组织损伤。
在短暂性MCAO发病后的最初6小时内，HBO能高效减少梗死体积并改善神经行为学转归。在较晚时间点（≥12小时）进行HBO治疗会因增加梗死体积而产生有害作用。在永久性MCAO模型中，HBO未能改善梗死体积及临床结局。
