Critchley Lester A H, Huang Li
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China,
J Clin Monit Comput. 2014 Feb;28(1):83-93. doi: 10.1007/s10877-013-9499-5. Epub 2013 Aug 2.
Supra-sternal Doppler (USCOM Ltd., Sydney, Australia) can be used during anaesthesia to measure cardiac output (CO) and related flow parameters. However, before the USCOM can be used routinely, its utility and limitations need to be fully understood and critical information about its use disseminated. In "Window to the Circulation" we use the example of an elderly man undergoing major urological robotic surgery to highlight the utility and limitations of intra-operative USCOM use. USCOM readings were verified against oesophageal Doppler. Despite the lack of major blood loss (<500 ml in 8-h), significant changes in haemodynamics were recorded. CO ranged from 3.2 to 8.3 l/min. The quality of USCOM scans and reliability of data was initially poor, but improved as CO increased as surgery progressed. When USCOM scans became acceptable the correlation with oesophageal Doppler was R(2) = 8.0 (p < 0.001). Several characteristic features of the supra-sternal Doppler scans were identified: Aortic and pulmonary flow waves, valve closure, E and A waves, false A-wave and aberrant arterial flow patterns. Their identification helped with identifying the main flow signal across the aortic valve. The USCOM has the potential to monitor changes in CO and related flow parameters intra-operatively and thus help the anaesthetist to more fully understand the patient's haemodynamics. However, achieving a good quality scan is important as it improves the reliability of USCOM data. The supra-sternal route is rich in flow signals and identifying the aortic valve signal is paramount. Recognizing the other characteristic waveforms in the signal helps greatly.
胸骨上多普勒（澳大利亚悉尼USCOM有限公司）可在麻醉期间用于测量心输出量（CO）及相关血流参数。然而，在USCOM能够常规使用之前，需要充分了解其效用和局限性，并传播有关其使用的关键信息。在“循环之窗”中，我们以一名接受大型泌尿外科机器人手术的老年男性为例，突出术中使用USCOM的效用和局限性。USCOM读数与食管多普勒测量结果进行了比对验证。尽管术中失血不多（8小时内<500毫升），但仍记录到血流动力学的显著变化。心输出量范围为3.2至8.3升/分钟。最初，USCOM扫描的质量和数据可靠性较差，但随着手术进展，心输出量增加，其质量有所改善。当USCOM扫描结果可接受时，与食管多普勒的相关性为R(2)=8.0（p<0.001）。胸骨上多普勒扫描的几个特征被识别出来：主动脉和肺动脉血流波形、瓣膜关闭、E波和A波、假A波以及异常动脉血流模式。识别这些特征有助于确定主动脉瓣的主要血流信号。USCOM有潜力在术中监测心输出量及相关血流参数的变化，从而帮助麻醉医生更全面地了解患者的血流动力学情况。然而，获得高质量的扫描很重要，因为这能提高USCOM数据的可靠性。胸骨上途径富含血流信号，识别主动脉瓣信号至关重要。识别信号中的其他特征波形也非常有帮助。
