Müller M, Bianchi O, Erülkü S, Stock C, Schwerdtfeger K
Department of Neurology, Saarland University Hospital, Kirrberger-Strasse, D-66421 Homburg/Saar, Germany.
Acta Neurochir (Wien). 2003 Aug;145(8):643-7; discussion 647-8. doi: 10.1007/s00701-003-0060-z.
Whether the phase relationship (phase shift) between cerebral blood flow velocity as assessed by transcranial Doppler ultrasound and blood pressure at 0.1 Hz can be used to assess cerebral autoregulation (CA) in patients with severe traumatic brain injury (TBI).
In 33 healthy volunteers (mean age, SD; 37+/-17 years, range 17-65) middle cerebral artery (MCA) blood velocity (V) was recorded simultaneously with finger blood pressure (BP) over a period of 10 minutes under normocapnic and hypocapnic conditions to generate normative data. In 27 patients with severe TBI (Glasgow Coma scale score < or =8) serial close in time investigations of cranial computed tomography (CT) scanning and phase shift assessment were performed on days 1, 3, 5, and 8 after trauma. Phase shift in the MCA was compared to brain parenchyma lesion size in the MCA territory on CT scanning. Lesion size was classified into 0, normal; 1, presence of a small lesion (diameter <3 cm); 2, presence of a large lesion (>3 cm).
Compared to normocapnia, hypocapnia significantly increased phase shift at 0.1 Hz from 78+/-28 degrees to 101+/-25 degrees (p < 0.001). In the TBI patients, 115 comparisons between CT findings and CA results were possible. Phase shift detected a pathological CA in 31 instances, which were more frequent in CT lesion type 2 (19/42) than in group 0 (7/44) and group 1 (5/29).
When CA is intended to be assessed by use of phase shift, the hyperventilation setting needs its own reference values. In MCA territories containing a traumatic lesion greater than 3 cm in diameter phase shift at 0.1 Hz will detect a high frequency (44%) of a disturbed state of CA.
经颅多普勒超声评估的脑血流速度与0.1赫兹时的血压之间的相位关系（相移）能否用于评估重型创伤性脑损伤（TBI）患者的脑自动调节功能（CA）。
在33名健康志愿者（平均年龄，标准差；37±17岁，范围17 - 65岁）中，在正常碳酸血症和低碳酸血症条件下，在10分钟内同时记录大脑中动脉（MCA）血流速度（V）和手指血压（BP）以生成标准数据。在27名重型TBI患者（格拉斯哥昏迷量表评分≤8）中，在创伤后第1、3、5和8天对颅骨计算机断层扫描（CT）和相移评估进行了一系列时间上接近的调查。将MCA中的相移与CT扫描时MCA区域的脑实质病变大小进行比较。病变大小分为0级，正常；1级，存在小病变（直径<3 cm）；2级，存在大病变（>3 cm）。
与正常碳酸血症相比，低碳酸血症使0.1赫兹时的相移从78±28度显著增加到101±25度（p<0.001）。在TBI患者中，CT结果与CA结果之间进行了115次比较。相移在31例中检测到病理性CA，在CT病变2型（19/42）中比在0组（7/44）和1组（5/29）中更频繁。
当打算通过相移评估CA时，过度通气设置需要其自身的参考值。在直径大于3 cm的创伤性病变的MCA区域，0.1赫兹时的相移将检测到高频率（44%）的CA紊乱状态。
