Department of Neurosurgery, St, Olavs Hospital, Trondheim, Norway.
Scand J Trauma Resusc Emerg Med. 2013 Nov 21;21:78. doi: 10.1186/1757-7241-21-78.
Cerebral perfusion pressure (CPP) is defined as the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). However, since patients with traumatic brain injury (TBI) are usually treated with head elevation, the recorded CPP values depends on the zero level used for calibration of the arterial blood pressure. Although international guidelines suggest that target values of optimal CPP are within the range of 50 - 70 mmHg in patients with TBI, the calibration of blood pressure, which directly influences CPP, is not described in the guidelines.The aim of this study was to review the literature used to support the CPP recommendations from the Brain Trauma Foundation, and to survey common clinical practice with respect to MAP, CPP targets and head elevation in European centres treating TBI patients.
A review of the literature behind CPP threshold recommendations was performed. Authors were contacted if the publications did not report how MAP or CPP was measured. A short questionnaire related to measurement and treatment targets of MAP and CPP was sent to European neurosurgical centres treating patients with TBI.
Assessment methods for CPP measurement were only retrieved from 6 of the 11 studies cited in the TBI guidelines. Routines for assessment of CPP varied between these 6 publications. The 58 neurosurgical centres that answered our survey reported diverging routines on how to measure MAP and target CPP values. Higher CPP threshold were not observed if blood pressure was calibrated at the heart level (p = 0.51).
The evidence behind the recommended CPP thresholds shows no consistency on how blood pressure is calibrated and clinical practice for MAP measurements and CPP target values seems to be highly variable. Until a consensus is reached on how to measure CPP, confusion will prevail.
脑灌注压（CPP）定义为平均动脉压（MAP）与颅内压（ICP）之差。然而，由于创伤性脑损伤（TBI）患者通常采用头高位治疗，因此记录的 CPP 值取决于动脉血压校准使用的零位。尽管国际指南建议 TBI 患者的最佳 CPP 目标值在 50-70mmHg 范围内，但指南并未描述直接影响 CPP 的血压校准。本研究旨在回顾支持脑创伤基金会 CPP 推荐的文献，并调查欧洲 TBI 治疗中心在 MAP、CPP 目标和头高位方面的常见临床实践。
对 CPP 阈值推荐背后的文献进行了回顾。如果出版物未报告如何测量 MAP 或 CPP，则会联系作者。向治疗 TBI 患者的欧洲神经外科中心发送了一份与 MAP 和 CPP 测量和治疗目标相关的简短问卷。
仅从 TBI 指南中引用的 11 项研究中的 6 项中检索到 CPP 测量的评估方法。这 6 篇出版物之间 CPP 评估的常规方法存在差异。回答我们调查的 58 个神经外科中心报告了如何测量 MAP 和目标 CPP 值的不同常规方法。如果血压在心脏水平校准，则不会观察到更高的 CPP 阈值（p=0.51）。
推荐 CPP 阈值背后的证据表明，在血压校准方面没有一致性，MAP 测量和 CPP 目标值的临床实践似乎差异很大。在如何测量 CPP 方面达成共识之前，混淆将继续存在。
