长时间身体倾斜过程中的脑灌注和动脉血流速度

Brain Perfusion and Arterial Blood Flow Velocity During Prolonged Body Tilting.

作者信息

Montero David, Rauber Sven

机构信息

Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland.

出版信息

Aerosp Med Hum Perform. 2016 Aug;87(8):682-7. doi: 10.3357/AMHP.4546.2016.

DOI:10.3357/AMHP.4546.2016

PMID:27634602

Abstract

BACKGROUND

It remains unknown whether brain perfusion is preserved and mirrored by middle cerebral blood flow velocity (MCA BFV) during prolonged changes in body posture. Herein, we examined the impact of sustained (180 min) 30° head-up (HUT) and head-down (HDT) tilt on brain perfusion, as determined by MCA BFV and blood flow in the extracranial arteries.

METHODS

In 10 healthy male subjects, arterial diameters, BFVs, and blood flows were determined in the left internal carotid (ICA) and vertebral (VA) arteries using duplex Doppler ultrasound in supine rest, and 5, 20, 60, 120, and 180 min following 30° HUT and HDT. MCA BFV was recorded throughout with transcranial Doppler ultrasound.

RESULTS

ICA as well as VA diameters and blood flows were unaltered during HUT. Likewise, brain blood flow and MCA BFV were preserved with HUT. In the HDT protocol, ICA and VA diameters were gradually increased, although ICA, VA, and brain blood flows were preserved. MCA BFV was progressively reduced during HDT. In addition, MCA BFV was positively associated with ICA BFV (β = 0.9) and negatively associated with ICA diameter (β = -125.5). MCA BFV was positively associated with brain blood flow during HUT (β = 0.2) but not HDT.

CONCLUSIONS

Brain perfusion is preserved whereas MCA BFV is progressively decreased and associated with extracranial arterial BFV during sustained 30° HDT. Therefore, MCA BFV may not be a surrogate of brain perfusion in conditions including prolonged HDT. Montero D, Rauber S. Brain perfusion and arterial blood flow velocity during prolonged body tilting. Aerosp Med Hum Perform. 2016; 87(8):682-687.

摘要

背景

在长时间身体姿势改变过程中，脑灌注是否得以维持并可通过大脑中动脉血流速度（MCA BFV）反映出来，目前尚不清楚。在此，我们研究了持续（180分钟）30°头高位（HUT）和头低位（HDT）倾斜对脑灌注的影响，脑灌注通过MCA BFV和颅外动脉血流来确定。

方法

对10名健康男性受试者，在仰卧休息时以及30°HUT和HDT后的5、20、60、120和180分钟，使用双功多普勒超声测定左颈内动脉（ICA）和椎动脉（VA）的动脉直径、BFV和血流。全程使用经颅多普勒超声记录MCA BFV。

结果

HUT期间，ICA以及VA的直径和血流未改变。同样，HUT时脑血流和MCA BFV得以维持。在HDT方案中，ICA和VA直径逐渐增加，尽管ICA、VA和脑血流得以维持。HDT期间MCA BFV逐渐降低。此外，MCA BFV与ICA BFV呈正相关（β = 0.9），与ICA直径呈负相关（β = -125.5）。HUT期间MCA BFV与脑血流呈正相关（β = 0.2），但HDT期间并非如此。