The Impact of Systemic Vasoconstrictors on the Cerebral Circulation of Anesthetized Patients
The Impact of Systemic Vasoconstrictors on the Cerebral Circulation of Anesthetized Patients
复制标题
全身血管收缩剂对麻醉患者脑循环的影响
作者：
S. Strebel;C. Kindler;B. Bissonnette;Gabriela Tschalèr;D. Deanovic
背景血管收缩剂对麻醉病人脑内血流动力学的影响是有争议的。使用经颅多普勒超声检查研究了苯肾上腺素和去甲肾上腺素对异氟烷或丙泊酚麻醉患者脑循环的影响。方法40例患者随机分为两组，分别在异氟醚和异丙酚麻醉下，用去甲肾上腺素和苯肾上腺素进行缩血管试验。同时测量大脑中动脉和同侧颈内动脉颅外段血流速度。在稳定麻醉期间以仰卧位进行基线记录（测试0）。在去甲肾上腺素或苯肾上腺素使平均动脉血压增加约20%后进行第二系列测量（测试1）。在持续输注去甲肾上腺素或苯肾上腺素的情况下，在通过患者略微抬头的体位抵消平均动脉压升高后获得最终系列结果（试验2）。结果两种缩血管剂均显著增加大脑中动脉平均血流速度（去甲肾上腺素：43 +/-11 cm/s至49 +/-11 cm/s;苯肾上腺素：43 +/-8 cm/s至48 +/-9 cm/s; +/-SD）和颈内动脉（去甲肾上腺素：27 +/-7 cm/s至31 +/-8 cm/s;苯肾上腺素：27 +/-9 cm/s至31 +/-10 cm/s）。在头高位时，在两条脑动脉中仅观察到微小且不显著的流速变化，与血管收缩剂或背景麻醉剂无关。结论本研究的结果表明，去甲肾上腺素和苯肾上腺素不直接影响麻醉患者的颅内血流动力学，而是与血管收缩剂观察到的血流动力学变化反映了背景麻醉剂对脑压力自动调节的影响。
Background The effect of vasoconstrictors on intracerebral hemodynamics in anesthetized patients is controversial. The influence of phenylephrine and norepinephrine on the cerebral circulation was investigated in isoflurane‐ or propofol‐anesthetized patients using transcranial Doppler ultrasonography. Methods Forty patients were randomly assigned to have vasoconstrictor tests with norepinephrine or phenylephrine during either isoflurane or propofol anesthesia. Blood flow velocities were simultaneously measured in the middle cerebral artery and ipsilateral extracranial internal carotid artery. Baseline recordings were done during stable anesthesia in a supine position (test 0). A second series of measurements were performed after norepinephrine or phenylephrine had increased mean arterial blood pressure by about 20% (test 1). With maintained norepinephrine or phenylephrine infusion, a final series of results were obtained after the increased mean arterial blood pressure was counteracted by a slightly head‐up patient position (test 2). Results Both vasoconstrictors significantly increased mean flow velocities in the middle cerebral artery (norepinephrine: 43 +/‐ 11 cm/s to 49 +/‐ 11 cm/s; phenylephrine: 43 +/‐ 8 cm/s to 48 +/‐ 9 cm/s; +/‐ SD) and internal carotid artery (norepinephrine: 27 +/‐ 7 cm/s to 31 +/‐ 8 cm/s; phenylephrine: 27 +/‐ 9 cm/s to 31 +/‐ 10 cm/s) in the isoflurane‐but not in the propofol‐anesthetized patients. In the head‐up position, only small and insignificant flow velocity changes were observed in both cerebral arteries independent of the vasoconstrictor or background anesthetic. Conclusions The results of the present study indicate that norepinephrine and phenylephrine do not directly affect intracranial hemodynamics in anesthetized patients, but rather that hemodynamic changes observed with vasoconstrictors reflect the effect of the background anesthetic agents on cerebral pressure autoregulation.
影响因子：
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作者：
BUSIJA, DW
通讯作者：
BUSIJA, DW