Eubaric hyperoxemia and experimental cerebral infarction
Eubaric hyperoxemia and experimental cerebral infarction
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DOI：
10.1002/ana.10322
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发表时间：
2002-11-01
影响因子：
11.2
通讯作者：
Auer, RN
中科院分区：
文献类型：
--
作者：
Flynn, EP;Auer, RN
我们探讨三个问题有关动脉氧合过度和局灶性缺血。(1)动脉高血氧血症水平越高，获益越大吗？(2)持续（缺血内加缺血后）氧疗的净效应对大脑中动脉梗死是有毒还是有益？(3)从自由基再灌注损伤理论来看，再灌注期高氧是否会对组织造成损伤？在2周的存活期评估了经受短暂、局灶性、常温、血糖正常的缺血的大鼠。在缺血期间，动脉高氧从98.9 +/- 4.0到312.2 +/-48.4mmHg改善了神经功能（p < 0.05），孤立的再灌注高氧血症也是如此，但在缺血期间和缺血后持续高氧血症治疗产生了最大的益处（p < 0.001）。在正常氧水平下，皮质梗死占大脑半球的6.5 ± 1.8%，而在高氧水平下，皮质梗死占大脑半球的2.3 ± 0.9%（p < 0.01）。在再灌注期间分离的高氧也减少了皮质坏死，从6.5%减少到2.7 ± 1.2%。然而，持续缺血和再灌注高氧血症仅导致0.2 ± 0.1%皮质坏死（p = 0.0005）。增加高氧血症的程度并不能增加获益。我们的结论是：（1）常压高氧血症改善神经和神经病理结果，（2）持续氧疗提供最大的好处，（3）再灌注高氧血症是有益的。这一发现将减轻临床对氧诱导再灌注损伤的担忧，并通过避免高压舱，鼓励临床试验研究动脉血氧过多症治疗中风。
We explore three questions concerning arterial hyperoxygenation and focal ischemia. (1) Does greater benefit accrue with higher levels of arterial hyperoxemia? (2) Is the net effect of continuous (intraischemic plus postischemic) oxygen therapy toxic, or beneficial to middle cerebral artery infarction? (3) In view of free radical theories of reperfusion injury, does hyperoxia isolated to the reperfusion period damage tissue? Rats subjected to transient, focal, normothermic, normoglycemic ischemia were assessed at 2 weeks' survival. Arterial hyperoxygenation from 98.9 +/- 4.0 to 312.2 +/- 48.4mm Hg during ischemia improved (p < 0.05) neurological function, as did isolated reperfusion hyperoxemia, but treatment with continuous hyperoxemia both during and after ischemia yielded greatest benefit (p < 0.001). Cortical infarcts constituted 6.5 +/- 1.8% of the hemisphere at normoxia, but 2.3 +/- 0.9% at hyperoxic levels (p < 0.01). Hyperoxia isolated to the reperfusion period also reduced cortical necrosis, from 6.5% to 2.7 ± 1.2%. However, continuous intraischemic and reperfusion hyperoxemia led to only 0.2 ± 0.1% cortical necrosis (p = 0.0005). Increasing the degree of hyperoxemia did not augment the benefit. We conclude that (1) eubaric hyperoxemia improves neurological and neuropathological outcome, (2) continuous oxygen therapy offers the greatest benefit, and (3) reperfusion hyperoxemia is beneficial. The findings should allay clinical concerns regarding oxygen-induced reperfusion injury, and, by obviating hyperbaric chambers, encourage clinical trials studying arterial hyperoxemia in treating stroke.