综述：颅脑损伤中脑灌注压的意义

众所周知，创伤性脑损伤后，低脑血流灌注（和脑灌注压（CPP）]是预后不良的重要原因。但尚不明确的是：改变脑血流抑或CPP，是否可以改善临床预后。最初的研究表明，提高CPP是有益的，脑创伤研究协会（Braill Trauma Foundation）将目标值定为70rnrnHg，并编入1996年版指南中。然而，随后的实践显示，达到此目标值并未带来显著的益处，而并发症的发生率却有所上升，因此将此目标值降低为60mmHg。近来，有证据表明，创伤性脑损伤后，脑的自身调节功能被破坏，这样就有学者提出，应对CPP进行个体化的调整。另外，随着先进的神经监测技术的出现，临床医生能够更加准确地观察血流动力学调节措施对脑代谢的影响。但现在仍然缺乏有力的证据支持调控CPP可改善预后这一观点。迄今为止，关于最佳脑灌注压的争论仍在继续。

It is now well recognized that low cerebral blood flow （and cerebral perfusion pressure （CPP）） is associated with poor outcome after traumatic brain injury. What is less dear is whether altering cerebral blood flow or CPP will lead to dinical improvement. Initial studies indicated that increasing CPP may be beneficial and the Brain Trauma Foundation acknowledged this by incorporating a target of 70 mm Hg in the 1996 guidelines. However, the lack of a demonstrable benefit and the increased complication rate associated with this approach led to a reduction in the CPP goal to 60 mm Hg. More recently, evidence that autoregulation may be disrupted after traumatic brain injury has led some authors to propose an individualized approach to CPP management. Furthermore, with the advent of advanced neuromonitoring techniques, clinicians are able to more dosely monitor the effects of hemodynamic manipulations on cerebral metabolism. As yet, there is no strong outcome evidence to support this approach. Until then, the current debate over the optimal approach to CPP management is likely to continue.