Kim Jeongho, Sato Hitoshi, Griffith Grant W, Cook Keith E
Department of Surgery, University of Michigan, Ann Arbor, Michigan 48109, USA.
ASAIO J. 2009 Jan-Feb;55(1):73-7. doi: 10.1097/MAT.0b013e318191500a.
Attachment of thoracic artificial lungs (TALs) can increase right ventricular (RV) afterload and decrease cardiac output (CO) under certain conditions. However, there is no established means of predicting the extent of RV dysfunction. The zeroth harmonic impedance modulus, Z0, was thus examined to determine its effectiveness at predicting CO during high afterload TAL attachment. The MC3 Biolung was attached in four adult sheep groups based on baseline (BL) pulmonary vascular resistance and TAL attachment mode: normal, parallel (n=7); normal, series (n=7); chronic pulmonary hypertension, parallel (n=5), and chronic pulmonary hypertension, series (n=5). The resistance of each attachment mode was increased incrementally and instantaneous pulmonary system hemodynamic data were acquired at each increment. The change in Z0 from BL, DeltaZ0, and percent change in CO (DeltaCO%) were then calculated to determine their relationship. The DeltaCO% varied significantly with DeltaZ0 (p<10(-40)) and DeltaZ02 (p<10(-4)) but not with the attachment and pulmonary hemodynamics group. The relationship between the variables for all sheep groups was DeltaCO%=0.215DeltaZ0(2)-7.14DeltaZ0+2.94 (R2=0.82) for DeltaZ0 in mm Hg/(L/min). Therefore, Z0 is an effective index for determining the CO during TAL attachment in both attachment modes with and without elevated pulmonary vascular resistance.
在某些情况下，植入胸腔人工肺（TALs）会增加右心室（RV）后负荷并降低心输出量（CO）。然而，目前尚无确定的方法来预测右心室功能障碍的程度。因此，研究了零阶谐波阻抗模量Z0，以确定其在高后负荷TAL植入期间预测心输出量的有效性。根据基线（BL）肺血管阻力和TAL植入模式，将MC3生物肺植入四组成年绵羊：正常，并联（n = 7）；正常，串联（n = 7）；慢性肺动脉高压，并联（n = 5），以及慢性肺动脉高压，串联（n = 5）。每种植入模式的阻力逐渐增加，并在每次增加时获取瞬时肺循环系统血流动力学数据。然后计算Z0相对于BL的变化量ΔZ0以及心输出量的变化百分比（ΔCO%），以确定它们之间的关系。ΔCO%与ΔZ0（p<10^(-40)）和ΔZ0²（p<10^(-4)）显著相关，但与植入模式和肺血流动力学分组无关。对于所有绵羊组，当ΔZ0以mmHg/（L/min）为单位时，变量之间的关系为ΔCO% = 0.215ΔZ0² - 7.14ΔZ0 + 2.94（R² = 0.82）。因此，Z0是在有和没有肺血管阻力升高的两种植入模式下确定TAL植入期间心输出量的有效指标。
