Cerebral autoregulation following head injury
Cerebral autoregulation following head injury
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DOI：
10.3171/jns.2001.95.5.0756
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发表时间：
2001-11-01
影响因子：
4.1
通讯作者：
Pickard, JD
中科院分区：
文献类型：
--
作者：
Czosnyka, M;Smielewski, P;Pickard, JD
对象。本研究采用经颅多普勒（TCD）超声检查脑损伤后脑自动调节、颅内压（ICP）、动脉压（ABP）和脑灌注压（CPP）的关系。作者利用ICP监测和TCD超声研究了大脑中动脉血流速度（FV）对自发性ABP或CPP变化的反应是否提供了关于大脑自动调节储备的可靠信息。在本研究中，该方法在187例头部损伤患者中得到了验证，这些患者镇静并接受机械通气。在持续20 ~ 120分钟的时间间隔内记录ICP、ABP和FV的波形。测定时间平均平均FV和CPP。FV和CPP之间的相关系数指数（平均自动调节指数[Mx]）在4分钟内计算，并在每次调查中取平均值。平均FV值的分布与自调节曲线的形状趋于一致，表明自调节阈值的下限（CPP < 55 min Hg）和上限（CPP < 105 min Hg）。Mx。无论是CPP还是ABP都被描绘成u型曲线。当存在颅内高压（颅内压大于或等于25mm Hg）和平均ABP过低（ABP < 75mm Hg）或过高（ABP bb0 125min Hg）时，自动调节受到干扰。自调节功能紊乱（p < 0.005）和ICP升高（p < 0.005）在预后不良的患者中比预后良好的患者更常见。自动调节不仅在高ICP或低ABP时受损，而且在CPP过高时也会受到干扰。当使用面向cpp的方案时，Mx可用于指导重症监护治疗。
Object. The goal of this study was to examine the relationship between cerebral autoregulation, intracranial pressure (ICP), arterial blood pressure (ABP), and cerebral perfusion pressure (CPP) after head injury by using transcranial Doppler (TCD) ultrasonography.Methods. Using ICP monitoring and TCD ultrasonography, the authors previously investigated whether the response of flow velocity (FV) in the middle cerebral artery to spontaneous variations in ABP or CPP provides reliable information about cerebral autoregulatory reserve. In the present study, this method was validated in 187 head-injured patients who were sedated and receiving mechanical ventilation. Waveforms of ICP, ABP, and FV were recorded over intervals lasting 20 to 120 minutes. Time-averaged mean FV and CPP were determined. The correlation coefficient index between FV and CPP (the mean index of autoregulation [Mx]) was calculated over 4-minute epochs and averaged for each investigation.The distribution of averaged mean FV values converged with the shape of the autoregulatory curve, indicating lower (CPP < 55 min Hg) and upper (CPP > 105 min Hg) thresholds of autoregulation. The relationship between the Mx. and either the CPP or ABP was depicted as a U-shaped curve. Autoregulation was disturbed in the presence of intracranial hypertension (ICP greater than or equal to 25 mm Hg) and when mean ABP was too low (ABP < 75 mm Hg) or too high (ABP > 125 min Hg). Disturbed autoregulation (p < 0.005) and higher ICP (p < 0.005) occurred more often in patients with unfavorable outcomes than in those with favorable outcomes.Conclusions. Autoregulation not only is impaired when associated with a high ICP or low ABP, but it can also be disturbed by too high a CPP. The Mx can be used to guide intensive care therapy when CPP-oriented protocols are used.