SYSTEMIC HEMODYNAMICS AFFECTING CARDIAC-OUTPUT DURING HYPOCAPNIC AND HYPERCAPNIC HYPOXIA
SYSTEMIC HEMODYNAMICS AFFECTING CARDIAC-OUTPUT DURING HYPOCAPNIC AND HYPERCAPNIC HYPOXIA
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DOI：
10.1152/jappl.1986.60.4.1230
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发表时间：
1986-04-01
影响因子：
3.3
通讯作者：
MELLINS, RB
中科院分区：
文献类型：
--
作者：
DAVIDSON, D;STALCUP, SA;MELLINS, RB
在长期使用仪器的未麻醉绵羊吸入导致低碳酸血症性缺氧（H）[动脉pH（pHa）= 7.53，动脉氧分压（PaO2）= 30 Torr，动脉二氧化碳分压（PaCO2）= 29 Torr]或高碳酸血症性缺氧（HCH）的气体混合物中，检查了涉及心输出量（CO）控制的全身血流动力学调节。（pHa = 7.14，PaO2 = 34 Torr，PaCO2 = 72 Torr）1 h。H（n = 7）和HCH（n = 6）分别导致CO增加26%和61%，HCH期间平均体循环动脉压升高幅度更大。H和HCH都导致外周体循环的血流量增加（微球法），包括大脑、心脏、膈肌和非呼吸骨骼肌（后者的血流量在H期间增加了120%，在HCH期间增加了380%）。胃肠道和肾脏血流量保持不变，在H和HCH。在基线条件下，绿色染料从肺动脉到后肢和肠的区域静脉的通过时间分别为5.0和8.2秒，而六氯环己烷则保持不变。在六氯环己烷，区域O2消耗增加274%的后肢和肠道减少39%。总的儿茶酚胺在H期间上升了250%，在HCH期间上升了3，700%。在低碳酸血症和高碳酸血症缺氧期间，CO部分通过全身血液动力学调节而增加，包括血流的重新分布和血容量向快速通过时间外周系统回路的易位。交感神经系统可能在介导这些全身血流动力学调节中起重要作用。
Systemic hemodynamic adjustments involved in the control of cardiac output (CO) were examined in chronically instrumented unanesthetized sheep inhaling gas mixtures resulting in hypocapnic hypoxia (H) [arterial pH (pHa) = 7.53, arterial partial pressure of O2 (PaO2) = 30 Torr, arterial partial pressure of CO2 (PaCO2) = 29 Torr] or hypercapnic hypoxia (HCH) (pHa = 7.14, PaO2 = 34 Torr, PaCO2 = 72 Torr) for 1 h. H (n = 7) and HCH (n = 6) resulted in 26% and 61% increase in CO, respectively, and mean systemic arterial pressure rose to a greater extent during HCH. Both H and HCH resulted in increased blood flow (microsphere method) to the peripheral systemic circulation including the brain, heart, diaphragm, and nonrespiratory skeletal muscle (the latter blood flow increased 120% during H and 380% during HCH). Gastrointestinal and renal blood flow remained unchanged during H and HCH. Transit time of green dye from the pulmonary artery to regional veins in the hindlimb and intestine was 5.0 and 8.2 s, respectively, during base-line conditions and remained unchanged with HCH. During HCH, regional O2 consumption increased 274% for the hindlimb and decreased 39% for the intestine. Total catecholamines rose 250% during H and 3,700% during HCH. During hypocapnic and hypercapnic hypoxia, CO is augmented in part by systemic hemodynamic adjustments that include a redistribution of blood flow and a translocation of blood volume to the fast transit time peripheral systemic circuit. The sympathetic nervous system may play an important role in mediating these systemic hemodynamic adjustments.