Page 138 - 先天性心脏病的导管术：从婴幼儿期到成人期

120 先天性心脏病的导管术：从婴幼儿期到成人期

肾静脉流的 IVC 的隔膜上方，这会污染样品。
174 J. P. S. Jones and L. N. Benson
除了上述流量计算之外，还可以确定心脏向组织输送氧气的效率的评估。全球氧
O 2 ER is 0.2–0.3, indicating that only 20–30% of the delivered
气输送（DO 2 ），也称为全身氧气输送（SOT），是指从肺部输送到全身的氧气量。
oxygen is utilized. This spare capacity enables the body to cope
J. P. S. Jones and L. N. Benson
174
with a fall in DO 2 without early compromise in aerobic respiration.
它是总血流量或心输出量（Q s ）与动脉血氧含量（C a O 2 ）的乘积，以 mL/min 表示：
DO 2 氧气提取率（O 2 = Q s × C a O 2 ）是 VO 2 的比值 O 2 至 DO 2 。和表示被组织吸收到微
O 2 ER is 0.2–0.3, indicating that only 20–30% of the delivered
oxygen is utilized. This spare capacity enables the body to cope
循环中的氧气的比例，O 2 ER = VO 2 /DO 2 。正常的 O 2 ER 是 0.2-0.3，表明只有 20%-30%
11.6 Resistance
with a fall in DO 2 without early compromise in aerobic respiration.
的输送的氧气被利用。这种备用能力使人体能够应付 DO 2 的下降，而不会及早进行无
Resistance in the vascular circuit is the difference in pressure
氧呼吸。 between the two ends of the circuit divided by the flow. In the
11.6 Resistance
body, circulation is influenced by the resistance imposed to the
heart by the vascular bed. For the right heart, the pulmonary vas-
Resistance in the vascular circuit is the difference in pressure
cular bed will determine pulmonary vascular resistance and can
between the two ends of the circuit divided by the flow. In the
be calculated by the following equation:
11.6 血管阻力
body, circulation is influenced by the resistance imposed to the
heart by the vascular bed. For the right heart, the pulmonary vas-
PVR
mPAPmLAP
Qp
/
血管阻力是回路两端之间的压力差除以流量。在体内，循环受到血管床对心脏施

cular bed will determine pulmonary vascular resistance and can
be calculated by the following equation:
where PVR is pulmonary vascular resistance, mPAP is mean pul-
加的阻力的影响。对于右心脏，肺血管床将确定肺血管阻力，可以通过以下方程式计算：
monary artery pressure, mLA p is mean left atrial pressure (alter-
PVR
mPAPmLAP
/
Qp
natively, pulmonary vein or PCWP may be used), and Q p is

pulmonary blood flow. Similarly, systemic vascular resistance can
其中 PVR 是肺血管阻力，mPAP 是平均肺动脉压，mPA P 是平均左心房压（或者，
where PVR is pulmonary vascular resistance, mPAP is mean pul-
be calculated as follows:
可以使用肺静脉或 PCWP），Q p 是肺血流。同样，全身血管阻力可计算如下：
monary artery pressure, mLA p is mean left atrial pressure (alter-
SVR
natively, pulmonary vein or PCWP may be used), and Q p is
mAoPmRAP
Qs
/

pulmonary blood flow. Similarly, systemic vascular resistance can
be calculated as follows:
其中 SVR 为全身血管阻力，mAo p 为平均动脉压，mRA p 为平均右心房压，Q s
where SVR is systemic vascular resistance, mAo p is mean arterial
为全身血流。阻力单位通常表示为 mmHg/L/min，称为伍德单位，这是儿科心脏病
pressure, mRA p is mean right atrial pressure, and Q s is systemic
SVR
mAoPmRAP
/
Qs
blood flow. Resistance units are commonly expressed as mmHg/l/

−5
专家最常用的术语。阻力单位也可以表示为 dyne·sec·cm 。将伍德单位转换为
min referred as Wood units, the term most commonly used by pedi-
where SVR is systemic vascular resistance, mAo p is mean arterial
−5
atric cardiologists. Resistance units can also be expressed as
dyne·sec·cm ，乘以 80。当 Q p 和 Q s 为身体表面积时，阻力也应被表示为伍德单位。
pressure, mRA p is mean right atrial pressure, and Q s is systemic
dyne·sec·cm . To convert Wood units to dyne.sec.cm, multiply by
−5
应该注意的是，为了校正身体 BSA，PVR 乘以 BSA。例如，如果 BSA 为 0.5 平方米，
blood flow. Resistance units are commonly expressed as mmHg/l/
80. When Q p and Q s are indexed for body surface area, resistance
min referred as Wood units, the term most commonly used by pedi-
Q p = 2 L/min，mPAP = 20 mmHg，mLAP = 8 mmHg，PVR = （20−8）/2 = 6
should also be indexed and expressed as Wood units ∙ m . Note 个伍德单位，
2
atric cardiologists. Resistance units can also be expressed as
should be taken that to correct for body BSA, the PVR is multiplied
2
和 PVRI = （（20−8）/2） × 0.5 = 3 伍德单位 *m 。 2
−5
dyne·sec·cm . To convert Wood units to dyne.sec.cm, multiply by
by the BSA. For example, if the BSA is 0.5 m , Q p = 2 l/min,
80. When Q p and Q s are indexed for body surface area, resistance
mPAP = 20 mmHg, mLAP = 8 mmHg, the PVR = (20–8)/2 = 6
should also be indexed and expressed as Wood units ∙ m . Note
2
Wood units, and PVRI = ((20–8)/2) × 0.5 = 3 Wood units ∙ m .
2
should be taken that to correct for body BSA, the PVR is multiplied
by the BSA. For example, if the BSA is 0.5 m , Q p = 2 l/min,
11.7 肺血管反应性测试 2
mPAP = 20 mmHg, mLAP = 8 mmHg, the PVR = (20–8)/2 = 6
2
Wood units, and PVRI = ((20–8)/2) × 0.5 = 3 Wood units ∙ m .
肺血管反应性的评估在肺动脉高压的管理和评估中起着重要作用。在基线血流动
力学评估之后，患者暴露于 100% 氧气（至少 10 分钟）并重复饱和度和压力测量。
当给予高浓度氧（F I O 2 大于等于 30%）时，在计算中必须考虑溶解氧。如果不这样做，
将低估 PVR。可增加 PVR 的情况包括缺氧，高碳酸血症，红细胞增多，交感神经肺
栓塞增加，毛细血管前肺水肿，肺受压（胸腔积液），机械通气和胸腔内正压。PVR