Continuous cardiac output and left atrial pressure monitoring by long time interval analysis of the pulmonary artery pressure waveform: proof of concept in dogs.
Continuous cardiac output and left atrial pressure monitoring by long time interval analysis of the pulmonary artery pressure waveform: proof of concept in dogs.
复制标题
通过肺动脉压力波形的长时间间隔分析进行连续心输出量和左心房压力监测：狗的概念验证。
DOI：
10.1152/japplphysiol.90834.2008
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Mukkamala,Ramakrishna
中科院分区：
文献类型：
--
作者：
Xu,Da;Olivier,NBari;Mukkamala,Ramakrishna
我们开发了一种技术，以不断（即，通过对肺动脉压（PAP）波形的数学分析，自动地）监测心输出量（CO）和左心房压（ECG）。该技术是唯一的几个先前的相关技术，因为它联合估计两个血液动力学变量和分析的PAP波形的时间尺度大于心动周期，其中波反射和惯性效应不再是主要因素。首先，分析6分钟PAP波形段，以便确定如果心脏活动突然停止（即，在混淆波反射和惯性效应消失之后）。然后，计算该指数衰减的时间常数，并根据Windkessel模型假设其与平均肺动脉阻力成比例，而平衡压力被视为平均阻力。最后，类似于调用欧姆定律来确定平均比例CO，并且容易用一次热稀释测量来校准。为了评估该技术，我们在5只狗中进行了实验，在常见的血流动力学干预期间，同时记录了PAP波形和准确但高度侵入性的主动脉流量探头CO和导管测量值。我们的结果显示，总体校准CO和绝对CO2均方根误差分别为15.2%和1.7 mmHg。为了比较，经典舒张末期PAP估计的均方根误差为4.7 mmHg。在未来成功的人体试验中，该技术可能用于肺动脉导管重症患者的连续血流动力学监测。
We developed a technique to continuously (i.e., automatically) monitor cardiac output (CO) and left atrial pressure (LAP) by mathematical analysis of the pulmonary artery pressure (PAP) waveform. The technique is unique to the few previous related techniques in that it jointly estimates the two hemodynamic variables and analyzes the PAP waveform over time scales greater than a cardiac cycle wherein wave reflections and inertial effects cease to be major factors. First, a 6-min PAP waveform segment is analyzed so as to determine the pure exponential decay and equilibrium pressure that would eventually result if cardiac activity suddenly ceased (i.e., after the confounding wave reflections and inertial effects vanish). Then, the time constant of this exponential decay is computed and assumed to be proportional to the average pulmonary arterial resistance according to a Windkessel model, while the equilibrium pressure is regarded as average LAP. Finally, average proportional CO is determined similar to invoking Ohm's law and readily calibrated with one thermodilution measurement. To evaluate the technique, we performed experiments in five dogs in which the PAP waveform and accurate, but highly invasive, aortic flow probe CO and LAP catheter measurements were simultaneously recorded during common hemodynamic interventions. Our results showed overall calibrated CO and absolute LAP root-mean-squared errors of 15.2% and 1.7 mmHg, respectively. For comparison, the root-mean-squared error of classic end-diastolic PAP estimates of LAP was 4.7 mmHg. On future successful human testing, the technique may potentially be employed for continuous hemodynamic monitoring in critically ill patients with pulmonary artery catheters.