Su Bai-Chuan, Lin Chih-Chung, Su Chih-Wen, Hui Yu-Ling, Tsai Yung-Fong, Yang Ming-Wen, Lui Ping-Wing
Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan, ROC.
Acta Anaesthesiol Taiwan. 2008 Dec;46(4):171-7. doi: 10.1016/S1875-4597(09)60005-9.
The ultrasonic cardiac output monitor (USCOM; USCOM Pty. Ltd., Sydney, NSW, Australia) has been accepted as a noninvasive device for measuring cardiac function in various clinical conditions. The present study aimed at comparing the accuracy of this device with that of the thermodilution technique in recipients in the early postoperative period after liver transplantation.
Fifteen mechanically ventilated patients were studied on the first postoperative day after liver transplantation. We compared the left-sided and right-sided cardiac output (CO) determined by USCOM with that obtained from the thermodilution technique with a pulmonary artery catheter every 8 hours in the intensive care unit. Each patient received a total of four paired measurements. Bland-Altman analysis was used for bias and precision testing. The CO measured by USCOM and the thermodilution method were considered interchangeable if the limits of agreement lay within +/- 1 L per minute or 20% of the mean CO.
Forty-eight paired left-sided CO measurements were obtained from 12 patients. Three patients were excluded due to unacceptable signals. Comparison of these two techniques revealed a bias of 0.13 L per minute and limits of agreement at -0.65 L and 0.92 L per minute. Fifty-six paired right-sided CO measurements were obtained from 14 patients with one patient excluded due to an unobtainable optimal signal. A bias of 0.11 L per minute with limits of agreement at -0.51 L and 0.72 L per minute were found for these two techniques.
This is the first study to evaluate the accuracy of USCOM in the post-liver transplant setting. This device is accurate in measuring CO in liver transplant recipients postoperatively. Possible risks of arrhythmia, infection and pulmonary artery rupture can be avoided because of its noninvasive nature. USCOM should be considered as an alternative in hemodynamic monitoring after liver transplantation.
超声心输出量监测仪（USCOM；澳大利亚新南威尔士州悉尼市的USCOM私人有限公司）已被公认为是一种在各种临床情况下用于测量心功能的无创设备。本研究旨在比较该设备与热稀释技术在肝移植术后早期受者中的准确性。
对15例机械通气的患者在肝移植术后第一天进行研究。在重症监护病房，我们每8小时比较一次由USCOM测定的左右心输出量（CO）与通过肺动脉导管热稀释技术获得的心输出量。每位患者共接受四次配对测量。采用Bland-Altman分析进行偏差和精密度测试。如果一致性界限在每分钟±1 L或平均CO的20%以内，则认为USCOM测量的CO和热稀释法测量的CO可互换。
从12例患者中获得了48对左侧CO测量值。3例患者因信号不可接受而被排除。这两种技术的比较显示偏差为每分钟0.13 L，一致性界限为每分钟-0.65 L和0.92 L。从14例患者中获得了56对右侧CO测量值，1例患者因无法获得最佳信号而被排除。这两种技术的偏差为每分钟0.11 L，一致性界限为每分钟-0.51 L和0.72 L。
这是第一项评估USCOM在肝移植后环境中准确性的研究。该设备在测量肝移植受者术后的CO方面是准确的。由于其无创性，可以避免心律失常、感染和肺动脉破裂等潜在风险。USCOM应被视为肝移植后血流动力学监测的一种替代方法。
