Vinayagam D, Patey O, Thilaganathan B, Khalil A
Fetal Medicine Unit, St George's Hospital, St George's University of London, London, UK.
Ultrasound Obstet Gynecol. 2017 Jan;49(1):32-38. doi: 10.1002/uog.15915.
To compare non-invasive hemodynamic measurements obtained in pregnant and postpartum women using two automated cardiac output monitors against those obtained by two-dimensional (2D) transthoracic echocardiography (TTE).
This was a cross-comparison study into which we recruited 114 healthy women, either with normal singleton pregnancy (across all three trimesters) or within 72 hours following delivery. Cardiac output estimations were obtained non-invasively using two different monitors, Ultrasound Cardiac Output Monitor (USCOM®, which uses continuous-wave Doppler analysis of transaortic blood flow) and Non-Invasive Cardiac Output Monitor (NICOM®, which uses thoracic bioreactance), and 2D-TTE. The performance of each monitor was assessed relative to that of TTE by calculating bias, precision, 95% limits of agreement and mean percentage difference (MPD). Intraobserver repeatability was assessed for both monitors and interobserver reproducibility was assessed for USCOM, NICOM being operator-independent.
Following exclusions due to poor-quality results of a monitor or TTE, or for medical reasons, our analysis included 98 women (29 in the first trimester, 25 in the second and 21 in the third, and 23 postpartum). For cardiac output estimation, when compared with TTE, USCOM had a bias ranging from 0.4 to 0.9 L/min. The MPD of USCOM was 29% in the third-trimester cohort. NICOM had a bias ranging from -1.0 to 0.6 L/min, with a MPD of 32% in the third-trimester group. There was limited agreement between the cardiac output monitors and TTE in the first and second trimesters, with a MPD of 38% for USCOM in both first and second trimesters, and 71% and 61% for NICOM in first and second trimesters, respectively. For cardiac output estimation using USCOM, we found excellent intraobserver repeatability (intraclass correlation coefficient (ICC), 0.97; 95% CI, 0.95-0.98) and interobserver reproducibility (ICC, 0.90; 95% CI, 0.81-0.94), and the repeatability for NICOM was comparable (ICC, 0.95; 95% CI, 0.93-0.97).
We found good agreement of both USCOM and NICOM when compared with 2D-TTE, specifically in the third trimester of pregnancy. Both devices had good intraobserver repeatability and either had good interobserver reproducibility or were operator-independent. Future studies should take into account the significant differences in the precise maternal hemodynamic values obtained by these devices, and consider developing device-specific reference ranges in pregnancy and the postpartum period. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
比较使用两种自动心输出量监测仪对孕妇和产后妇女进行的无创血流动力学测量结果与二维（2D）经胸超声心动图（TTE）测量结果。
这是一项交叉比较研究，我们招募了114名健康女性，包括正常单胎妊娠（涵盖所有三个孕期）的女性或产后72小时内的女性。使用两种不同的监测仪无创获取心输出量估计值，即超声心输出量监测仪（USCOM®，使用经主动脉血流的连续波多普勒分析）和无创心输出量监测仪（NICOM®，使用胸生物电阻抗），以及2D-TTE。通过计算偏差、精密度、95%一致性界限和平均百分比差异（MPD）来评估每个监测仪相对于TTE的性能。对两种监测仪评估了观察者内重复性，对USCOM评估了观察者间再现性，NICOM不依赖操作者。
由于监测仪或TTE结果质量差或出于医学原因进行排除后，我们的分析纳入了98名女性（孕早期29名，孕中期25名，孕晚期21名，产后23名）。对于心输出量估计，与TTE相比，USCOM的偏差范围为0.4至0.9升/分钟。在孕晚期队列中，USCOM的MPD为29%。NICOM的偏差范围为-1.0至0.6升/分钟，在孕晚期组中MPD为32%。在孕早期和孕中期，心输出量监测仪与TTE之间的一致性有限，USCOM在孕早期和孕中期的MPD均为38%，NICOM在孕早期和孕中期的MPD分别为71%和61%。对于使用USCOM进行的心输出量估计，我们发现观察者内重复性极佳（组内相关系数（ICC），0.97；95%CI，0.95 - 0.98）和观察者间再现性良好（ICC，0.90；95%CI，0.81 - 0.94），NICOM的重复性与之相当（ICC，0.95；95%CI，0.93 - 0.97）。
与2D-TTE相比，我们发现USCOM和NICOM都具有良好的一致性，特别是在妊娠晚期。两种设备都具有良好的观察者内重复性，并且要么具有良好的观察者间再现性，要么不依赖操作者。未来的研究应考虑这些设备所获得的精确母体血流动力学值的显著差异，并考虑制定孕期和产后特定设备的参考范围。版权所有©2016 ISUOG。由John Wiley & Sons Ltd出版。
