超声观察呼吸运动对脑静脉颅外回流的影响

Ultrasound in assessing the influence of respiration on cerebral venous outflow

目的探讨不同体位条件下呼吸运动对脑静脉颅外回流的影响。方法嘱40名健康志愿者分别取坐位和仰卧位,以超声观测颈内静脉和椎静脉在平静呼吸、深吸气末和深呼气末时的血流量变化。结果卧位平静呼吸时,颈内静脉和椎静脉血流量分别占脑血流总量的66.94%和4.17%;深吸气末颈内静脉所占比例增至86.61%,椎静脉所占比例减至1.69%。坐位平静呼吸时,颈内静脉和椎静脉血流量分别占脑血流总量的18.08%和14.73%;深吸气末颈内静脉所占比例增至89.68%,椎静脉所占比例减至1.86%。在深呼气末,卧位和坐位时颈内静脉、椎静脉血流量与平静呼吸时的差异均无统计学意义。结论卧位和坐位时,深吸气均使得脑静脉通过颈内静脉向颅外回流的比例显著增加。

Objective To observe the influence of the respiration on cerebral venous outflow under different body position with color-coded duplex sonography. Methods A total of 40 healthy volunteers were enrolled. Blood flow of internal jugu lar vein （IJV） and vertebral vein （VV） in quiet breath, deep inspiration and deep expiration were measured with Doppler at supine and sitting position. Results At supine position, blood flow of IJV and VV accounted for 66.94% and 4.17% of total cerebral blood flow （tCBF） in quiet breath, respectively. In deep inspiration, the proportion of blood flow of IJV in tCBF increased to 86.61%, and of VV in tCBF decreased to 1.69 %. There was no statistical difference between the vol- ume of blood flow of IJV nor VV in deep expiration and quiet breath. At sitting position, the volume of blood flow of IJV and VV accounted for 18.08% and 14.73% of tCBF in quiet breath, respectively. In deep inspiration, the proportion of blood flow of IJV in tCBF increased to 89.68%, of VV in tCBF decreased to 1.86%. There was neither statistical differ ence between the volume of blood flow of IJV nor VV in deep expiration and quiet breath, Conclusion The proportion the blood flow of J.JV in tCBF increases significantly in forced breathing both at supine and sitting position.