Brain tissue oxygen tension response to induced hyperoxia reduced in hypoperfused brain
Brain tissue oxygen tension response to induced hyperoxia reduced in hypoperfused brain
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DOI：
10.3171/jns/2008/108/01/0053
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发表时间：
2008-01-01
影响因子：
4.1
通讯作者：
Robertson, Claudia S.
中科院分区：
文献类型：
--
作者：
Hlatky, Roman;Valadka, Alex B.;Robertson, Claudia S.
Object. PaO 2升高可使脑组织PO 2（PbtO（2））升高。然而，高氧引起的动脉O-2含量的小幅增加并没有增加O-2的输送，特别是当脑血流量（CBF）低时，高氧作为治疗干预的有效性仍然存在争议。本研究的目的是检查PO 2探针位点的局部（r）CBF在确定PbtO（2）对诱导的高氧反应中的作用。作者在基线常氧条件下和在I I I情况下将吸入O-2浓度增加至100%后测量PaO 2和PbtO（2）。在83例严重创伤性脑损伤患者中进行了稳定的氙增强计算机断层扫描CBF测量。反应性计算为PbtO（2）的变化× 100/PaO 2的变化。在5个rCBF水平（< 10、11-15、16-20、21-40和> 40 ml/100 g/min）下，O-2反应性存在显著差异（p < 0.001）。当rCBF < 20 ml/100 g/min时，高氧引起的PNO 2升高与rCBF> 20 ml/100 g/min时相比非常小。虽然脑血流量水平可能只是决定PbtO（2）对高氧反应的因素之一，但从这些结果中可以明显看出，最有可能从改善氧合中受益的大脑区域是最不可能增加PbtO（2）的区域。
Object. Increasing PaO2 can increase brain tissue PO2 (PbtO(2)). Nevertheless, the small increase in arterial O-2 content induced by hyperoxia does not increase O-2 delivery much, especially when cerebral blood flow (CBF) is low, and the effectiveness of hyperoxia as a therapeutic intervention remains controversial. The purpose of this study was to examine the role of regional (r)CBF at the site of the PO2 probe in determining the response of PbtO(2) to induced hyperoxia.Methods. The authors measured PaO2 and PbtO(2) at baseline normoxic conditions and after increasing inspired O-2 concentration to 100% on I I I occasion. in 83 patients with severe traumatic brain injury in whom a stable xenon-enhanced computed tomography measurement of CBF was available. The 0, reactivity was calculated as the change in PbtO(2) X 100/change in PaO2.Results. The O-2 reactivity was significantly different (p < 0.001) at the 5 levels of rCBF (< 10, 11-15, 16-20, 21-40, and > 40 ml/100 g/min). When rCBF was < 20 ml/100 g/min, the increase in PNO2 induced by hyperoxia was very small compared with the increase that occurred when rCBF was > 20 ml/100 g/min.Conclusions. Although the level of CBF is probably only one of the factors that determines the PbtO(2) response to hyperoxia, it is apparent from these results that the areas of the brain that would most likely benefit from improved oxygenation are the areas that are the least likely to have increased PbtO(2).