Ito Toshiro, Katsuda Shin-Ichiro, Horikoshi Yuko, Funyu Toru, Hazama Akihiro, Shirai Kohji
Department of Cellular and Integrative Physiology, Fukushima Medical University School of Medicine, Fukushima, Japan.
Department of Clinical Laboratory Sciences, School of Health Sciences, Fukushima Medical University, Fukushima, Japan.
Pulse (Basel). 2024 Jun 5;12(1):76-84. doi: 10.1159/000539480. eCollection 2024 Jan-Dec.
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.
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 Fifteen percent of the total blood volume was depleted at a rate of 2 mL/kg/min for 6 min; 15 min later, the withdrawn blood was re-transfused at the same rate.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) × PWV, 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.
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.
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.
急性出血会降低血压（BP），有时会导致低血容量性休克。此时，外周动脉理应收缩并增加外周血管阻力以升高血压。然而，目前尚无足够的动脉僵硬度指标。我们使用新的与血压无关的血管指数，即分别将心踝血管指数理论应用于兔的弹性（主动脉）和肌性（髂总股动脉）动脉所确定的αβ和ifβ，评估快速出血期间动脉僵硬度的变化。
11只日本雄性白兔在戊巴比妥麻醉下仰卧固定。以2 mL/kg/min的速度在6分钟内放血总量的15%；15分钟后，以相同速度回输抽出的血液。同时测量主动脉起始部（oA）、腹主动脉远端（dA）、左髂总动脉远端（fA）的压力波以及oA处的血流波。β值使用以下公式计算：β = 2ρ/PP × ln（SBP/DBP）× PWV，其中ρ、SBP、DBP和PP分别为血液密度、收缩压、舒张压和脉压。αβ、ifβ和主动脉-髂股β（aifβ）分别使用aPWV、ifPWV和aifPWV计算得出。
急性出血期间，oA、dA和fA处的血压显著下降。αβ和aifβ平均从出血前（对照）的3.7和5.0显著增加至出血时的5.0（约34%）和6.3（约26%），而ifβ从出血前的20.5显著降至出血结束后的17.1（约17%）。回输抽出的血液后观察到这些指数的反向变化。
总动脉僵硬度（aifβ）增加；然而，出血期间弹性动脉变硬而肌性动脉变软。这些结果将为血压下降期间提供有用的诊断信息。
