急性出血会降低血压(BP),有时会导致低血容量性休克。此时,外周动脉应该收缩并增加外周血管阻力以提高血压。然而,没有足够的动脉僵硬度指数。我们使用新的BP非依赖性血管指数评估快速出血期间动脉僵硬度的变化,aBeta和ifBeta,通过将心踝血管指数理论应用于弹性(主动脉)和肌肉(髂总-股)动脉来确定,分别,在兔子
■在戊巴比妥麻醉下,将11只日本白兔固定在仰卧位。15%的血液总量以2mL/kg/min的速度耗尽6分钟;15分钟后,抽取的血液以相同的速率再次输血。主动脉起源处的压力波(oA),腹主动脉远端(dA),左髂总动脉远端(fA),同时测量oA处的流动波。β使用以下公式计算:β=2ρ/PP×ln(SBP/DBP)×PWV2,其中ρ,SBP,DBP,PP是血液密度,收缩压,舒张压,和脉压,分别。aBeta,如果贝塔,和主动脉-髂-股β(aifBeta)使用aPWV计算,如果PWV,和aifPWV,分别。
■BP在oA时显著下降,dA,和急性出血期间的fA。aBeta和aifBeta从出血前的3.7和5.0(对照)显着增加到5.0(约34%)和6.3(约26%),而ifBeta从出血前的20.5显著下降至出血完成后的17.1(约17%)。通过输注取出的血液观察到这些指标的逆反应。
■总动脉僵硬度(aifBeta)增加;然而,弹性和肌肉动脉在出血期间变硬和变软,分别。这些结果将在血压下降期间提供有用的诊断信息。
UNASSIGNED: Acute hemorrhage decreases blood pressure (BP) and sometimes causes hypovolemic shock. At this time, peripheral arteries are supposed to contract and increase peripheral vascular resistance to raise BP. However, there has not been an adequate index of a degree of arterial stiffness. We assessed changes in arterial stiffness during rapid bleeding using new BP-independent vascular indices, aBeta and ifBeta, determined by applying the cardio-ankle vascular index theory to the elastic (aorta) and muscular (common iliac-femoral) arteries, respectively, in rabbits.
UNASSIGNED: Eleven Japanese white male rabbits were fixed at the supine position under pentobarbital anesthesia. Fifteen percent of the total blood volume was depleted at a rate of 2 mL/kg/min for 6 min; 15 min later, the withdrawn blood was re-transfused at the same rate. Pressure waves at the origin of the aorta (oA), distal end of the abdominal aorta (dA), distal end of the left common iliac artery (fA), and flow waves at oA were measured simultaneously.
Beta was calculated using the following formula:
beta = 2ρ/PP × ln(SBP/DBP) × PWV2, where ρ, SBP, DBP, and PP are blood density, systolic, diastolic, and pulse pressures, respectively. aBeta, ifBeta, and aortic-iliac-femoral
beta (aifBeta) were calculated using aPWV, ifPWV, and aifPWV, respectively.
UNASSIGNED: BP declined significantly at oA, dA, and fA during the acute bleeding. aBeta and aifBeta increased significantly from 3.7 and 5.0 before the bleeding (control) to 5.0 (about 34%) and 6.3 (about 26%) on average, while ifBeta decreased significantly from 20.5 before the bleeding to 17.1 (about 17%) after the completion of the bleeding. Reverse reactions of those indices were observed by transfusing the removed blood.
UNASSIGNED: Total arterial stiffness (aifBeta) increased; however, the elastic and muscular arteries stiffened and softened during the bleeding, respectively. These results would give useful diagnostic information during fall in BP.