Clinical Research Article Korean J Anesthesiol 2011 April 60(4): 237-243 DOI: 10.4097/kjae.2011.60.4.237 The uncalibrated pulse contour cardiac output during off- pump coronary bypass surgery: performance in patients with a low cardiac output status and a reduced left ventricular function Youn Yi Jo1, Jong Wook Song2, Young Chul Yoo2, Ji Young Park2, Jae Kwang Shim2, and Young Lan Kwak2 1Department of Anesthesiology and Pain Medicine, Gachon University of Medicine and Science, Gil Medical Center, Incheon, 2Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea Background: We compared the continuous cardiac index measured by the FloTrac/VigileoTM system (FCI) to that measured by a pulmonary artery catheter (CCI) with emphasis on the accuracy of the FCI in patients with a decreased left ventricular ejection fraction (LVEF) and a low cardiac output status during off-pump coronary bypass surgery (OPCAB). We also assessed the influence of several factors affecting the pulse contour, such as the mean arterial pressure (MAP), the systemic vascular resistance index (SVRI) and the use of norepinephrine. Methods: Fifty patients who were undergoing OPCAB (30 patients with a LVEF ≥ 40%, 20 patients with a LVEF < 40%) were enrolled. The FCI and CCI were measured and we performed a Bland-Altman analysis. Subgroup analyses were done according to the LVEF (< 40%), the CCI (≤ 2.4 L/min/m), the MAP (60-80 mmHg), the SVRI (1,600-2,600 dyne/s/cm5/m2) and the use of norepinephrine. Results: The FCI was reliable at all the time points of measurement with an overall bias and limit of agreement of -0.07 and 0.67 L/min/m2, respectively, resulting in a percentage error of 26.9%. The percentage errors in the patients with a decreased LVEF and in a low cardiac output status were 28.2% and 22.3%, respectively. However, the percentage error in the 91 data pairs outside the normal range of the SVRI was 40.2%. Conclusions: The cardiac output measured by the FloTrac/VigileoTM system was reliable even in patients with a decreased LVEF and in a low cardiac output status during OPCAB. Acceptable agreement was also noted during the period of heart displacement and grafting of the obtuse marginalis branch. (Korean J Anesthesiol 2011; 60: 237-243) Key Words: Cardiac output, Measurement techniques, Off pump coronary artery bypass. Received: July 19, 2010. Revised: October 8, 2010. Accepted: October 26, 2010. Corresponding author: Jae Kwang Shim, M.D., Ph.D., Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University Health System, 250, Seongsan-no, Seodaemun-gu, Seoul 120-752, Korea. Tel: 82-2-2228-8513, Fax: 82-2-364-2951, E-mail: aneshim@yuhs.ac This study is supported by a faculty research grant of Yonsei University College of medicine of 2007 (6-2007-0140). CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright ⓒ the Korean Society of Anesthesiologists, 2011 www.ekja.org