Zhu Richard, Atteya Gourg, Shelley Kirk H, Silverman David G, Alian Aymen A
Department of Anesthesiology, Yale University School of Medicine, 333 Cedar Street, P.O. Box 208051, New Haven, CT, 06520-8051, USA.
J Clin Monit Comput. 2014 Dec;28(6):591-6. doi: 10.1007/s10877-014-9555-9. Epub 2014 Jan 14.
During shoulder surgery, patients typically are placed in the beach chair position. In rare cases, this positioning has resulted in devastating outcomes of postoperative cerebral ischemia (Cullen and Kirby in APSF Newsl 22(2):25-27, 2007; Munis in APSF Newsl 22(4):82-83, 2008). This study presents a method to noninvasively and continuously hemodynamically monitor patients during beach chair positioning by using the photoplethysmograph signal recorded from a commercial pulse oximeter. Twenty-nine adults undergoing shoulder surgery were monitored before and after beach chair positioning with electrocardiogram, intermittent blood pressure, end tidal carbon dioxide, and photoplethysmograph via Nellcor finger pulse oximeter. Fast Fourier transform (FFT) was used to perform frequency-domain analysis on the photoplethysmograph (PPG) signal for data segments taken 80-120 s before and after beach chair positioning. The amplitude density of respiration-associated PPG oscillations was quantified measuring the height of the FFT peak at respiratory frequency. Results were reported as (median, interquartile range) and statistical analysis was performed using Wilcoxon sign rank test. Data were also collected when vasoactive drugs phenylephrine and ephedrine were used to maintain acceptable mean arterial pressure during a case. With beach chair positioning, all subjects who did not receive vasoactive drugs showed an increase in the FFT amplitude density of respiration-associated PPG oscillations (p < 0.0001) without change in pulse-associated PPG oscillations. The PPG was more accurate at monitoring the change to beach chair position than blood pressure or heart rate. With vasoactive drugs, pulse-associated PPG oscillations decreased only with phenylephrine while respiration-associated oscillations did not change. Frequency domain analysis of the PPG signal may be a better tool than traditional noninvasive hemodynamic parameters at monitoring patients during beach chair position surgery.
在肩部手术期间，患者通常被置于沙滩椅位。在极少数情况下，这种体位会导致术后脑缺血的灾难性后果（Cullen和Kirby于2007年发表在《美国麻醉医师协会新闻季刊》第22卷第2期第25 - 27页；Munis于2008年发表在《美国麻醉医师协会新闻季刊》第22卷第4期第82 - 83页）。本研究提出了一种方法，通过使用从商用脉搏血氧仪记录的光电容积脉搏波信号，在沙滩椅位摆放过程中对患者进行无创且连续的血流动力学监测。29名接受肩部手术的成年人在沙滩椅位摆放前后，通过Nellcor手指脉搏血氧仪进行心电图、间歇性血压测量、呼气末二氧化碳监测以及光电容积脉搏波监测。快速傅里叶变换（FFT）用于对沙滩椅位摆放前后80 - 120秒的数据段所采集的光电容积脉搏波（PPG）信号进行频域分析。通过测量呼吸频率下FFT峰值的高度来量化与呼吸相关的PPG振荡的幅度密度。结果以（中位数，四分位间距）形式报告，并使用Wilcoxon符号秩检验进行统计分析。在一例手术中，当使用血管活性药物去氧肾上腺素和麻黄碱来维持可接受的平均动脉压时，也收集了数据。在沙滩椅位摆放时，所有未接受血管活性药物的受试者显示与呼吸相关的PPG振荡的FFT幅度密度增加（p < 0.0001），而与脉搏相关的PPG振荡无变化。PPG在监测向沙滩椅位的转变方面比血压或心率更准确。使用血管活性药物时，仅去氧肾上腺素会使与脉搏相关的PPG振荡降低，而与呼吸相关的振荡无变化。在沙滩椅位手术期间，对PPG信号进行频域分析可能是比传统无创血流动力学参数更好的监测患者的工具。
