Awad Aymen A, Stout Robert G, Ghobashy M Ashraf M, Rezkanna Hoda A, Silverman David G, Shelley Kirk H
Department of Anesthesia, Yale University School of Medicine, New Haven, CT 06516, USA.
J Clin Monit Comput. 2006 Jun;20(3):175-84. doi: 10.1007/s10877-006-9018-z. Epub 2006 Apr 13.
For years researchers have been attempting to understand the relationship between central hemodynamics and the resulting peripheral waveforms. This study is designed to further understanding of the relationship between ear pulse oximeter waveforms, finger pulse oximeter waveforms and cardiac output (CO). It is hoped that with appropriate analysis of the peripheral waveforms, clues can be gained to help to optimize cardiac performance.
Part 1: Studying the effect of cold immersion test on plethysmographic waveforms. Part 2: Studying the correlation between ear and finger plethysmographic waveforms and (CO) during CABG surgery. The ear and finger plethysmographic waveforms were analyzed to determine amplitude, width, area, upstroke and downslope. The CO was measured using continuous PA catheter. Using multi-linear regression, ear plethysmographic waveforms, together with heart rate (HR), were used to determine the CO Agreement between the two methods of CO determination was assessed.
Part 1: On contralateral hand immersion, all finger plethysmographic waveforms were reduced, there was no significant change seen in ear plethysmographic waveforms, except an increase in ear plethysmographic width. Part 2: Phase 1: Significant correlation detected between the ear plethysmographic width and other ear and finger plethysmographic waveforms. Phase 2: The ear plethysmographic width had a significant correlation with the HR and CO. The correlation of the other ear plethysmographic waveforms with CO and HR are summarized (Table 5). Multi-linear regression analysis was done and the best fit equation was found to be: CO=8.084 - 14.248 x Ear width + 0.03 x HR+ 92.322 x Ear down slope+0.027 x Ear Area Using Bland & Altman, the bias was (0.05 L) but the precision (2.46) is large to be clinically accepted.
The ear is relatively immune to vasoconstrictive challenges which make ear plethysmographic waveforms a suitable monitor for central hemodynamic changes. The ear plethysmographic width has a good correlation with CO.
多年来，研究人员一直试图了解中心血流动力学与由此产生的外周波形之间的关系。本研究旨在进一步了解耳脉搏血氧饱和度波形、手指脉搏血氧饱和度波形与心输出量（CO）之间的关系。希望通过对外周波形进行适当分析，能够获得有助于优化心脏功能的线索。
第一部分：研究冷浸试验对体积描记波形的影响。第二部分：研究冠状动脉旁路移植术（CABG）手术期间耳和手指体积描记波形与（CO）之间的相关性。分析耳和手指体积描记波形以确定振幅、宽度、面积、上升支和下降支。使用连续肺动脉导管测量CO。采用多元线性回归，将耳体积描记波形与心率（HR）一起用于确定CO。评估两种CO测定方法之间的一致性。
第一部分：对侧手浸入时，所有手指体积描记波形均降低，耳体积描记波形未见明显变化，但耳体积描记宽度增加。第二部分：第一阶段：检测到耳体积描记宽度与其他耳和手指体积描记波形之间存在显著相关性。第二阶段：耳体积描记宽度与HR和CO存在显著相关性。总结了其他耳体积描记波形与CO和HR的相关性（表5）。进行了多元线性回归分析，发现最佳拟合方程为：CO = 8.084 - 14.248×耳宽度 + 0.03×HR + 92.322×耳下降支 + 0.027×耳面积。使用布兰德-奥特曼方法，偏差为（0.05L），但精度（2.46）较大，临床难以接受。
耳朵对血管收缩性刺激相对不敏感，这使得耳体积描记波形成为监测中心血流动力学变化的合适指标。耳体积描记宽度与CO具有良好的相关性。
