Butcher Isabella, Maas Andrew I R, Lu Juan, Marmarou Anthony, Murray Gordon D, Mushkudiani Nino A, McHugh Gillian S, Steyerberg Ewout W
Public Health Sciences, University of Edinburgh Medical School, Edinburgh, United Kingdom.
J Neurotrauma. 2007 Feb;24(2):294-302. doi: 10.1089/neu.2006.0032.
Hypotension following traumatic brain injury (TBI) is recognized as an important secondary insult that is associated with adverse outcome. We aimed to describe the relationship between actual levels of admission blood pressure and Glasgow Outcome Scale (GOS) at 6 months. Individual patient data from the IMPACT database were available on systolic (N = 6801) and mean arterial (N = 6647) blood pressure. Regression models with restricted cubic spline functions were used to explore the shape of the relationships between blood pressure and outcome in unadjusted and adjusted analyses. Proportional odds methodology was applied to quantify the strength of the associations across the full range of the GOS. Analyses were performed to search for threshold values. A smooth U-shaped relationship was observed between systolic (SBP) and mean arterial (MABP) blood pressures and outcome, without any evidence of an abrupt threshold effect. Best outcomes were observed for values of SBP of the order of 135 mm Hg and for values of MABP of the order of 90 mm Hg. Both lower (OR 1.53; 95% CI: 1.31-1.80) and higher levels (OR 1.42; CI: 1.20-1.68) of SBP and lower (OR 1.30; CI 1.12-1.51) and higher levels of MABP (OR 1.45; CI 1.19-1.76) were associated with poorer outcome. These findings were consistent across studies. The relationship between high blood pressure level and poorer outcome largely disappeared on adjusted analysis. Current guidelines for the management of blood pressure in TBI focus on the avoidance of hypotension as defined by SBP < 90 mm Hg. Our finding of a smooth relationship with improving outcome as SBP increases up to 135 mm Hg, while not supporting a strong causal inference, does suggest that current guidelines need to be reconsidered.
创伤性脑损伤（TBI）后的低血压被认为是一种重要的继发性损伤，与不良预后相关。我们旨在描述入院时实际血压水平与6个月时格拉斯哥预后量表（GOS）之间的关系。可从IMPACT数据库获得个体患者的收缩压（N = 6801）和平均动脉压（N = 6647）数据。在未调整和调整分析中，使用具有受限立方样条函数的回归模型来探索血压与预后之间关系的形状。应用比例优势方法来量化GOS全范围内关联的强度。进行分析以寻找阈值。观察到收缩压（SBP）和平均动脉压（MABP）与预后之间呈平滑的U形关系，没有任何突然阈值效应的证据。SBP约为135 mmHg和MABP约为90 mmHg时观察到最佳预后。较低（OR 1.53；95% CI：1.31 - 1.80）和较高水平（OR 1.42；CI：1.20 - 1.68）的SBP以及较低（OR 1.30；CI 1.12 - 1.51）和较高水平的MABP（OR 1.45；CI 1.19 - 1.76）与较差的预后相关。这些发现在各项研究中是一致的。在调整分析中，高血压水平与较差预后之间的关系基本消失。目前TBI血压管理指南侧重于避免收缩压<90 mmHg所定义的低血压。我们发现随着SBP升高至135 mmHg预后改善呈平滑关系，虽然不支持强烈的因果推断，但确实表明当前指南需要重新考虑。
