The study used ultrasonography to observe in three head positions how the flow velocities and diameters of three veins and also the angles composed of right subclavian vein, internal jugular vein and brachiocephalic vein changed.
采用超声显像技术观察三种头位时的右侧锁骨下静脉、颈内静脉和头臂静脉间的成角关系、静脉内径以及静脉血流速度的变化,从理论上推测右侧锁骨下静脉正确置管时的合理头位。