Comparison of continuous cardiac output measurements in patients after cardiac surgery

Abstract

Objective: To investigate in a direct comparison accuracy and precision of continuous cardiac output measurements assessed by continuous pulmonary artery thermodilution technique (TDCCO), continuous pulse contour analysis (PCCO), and noninvasive partial CO2-rebreathing technique (NICO) in patients after coronary artery bypass grafting (CABG) during the postoperative period. Design: Prospective, controlled clinical study. Setting: University hospital. Participants: Twenty-two patients undergoing elective CABG surgery. Interventions: Hemodynamic measurements were performed after admission to the ICU and in sequence every 2 hours during the subsequent 6-hour period. Simultaneously, cardiac output (CO) was measured using a TDCCO, PCCO, and NICO. After the continuous cardiac output measurements were read, bolus thermodilution-derived cardiac output was obtained from thermodilution curves detected in the pulmonary artery (TDBCOpa). Four intermittent consecutive boli consisting of 10 mL of ice-cold saline were randomly injected over the ventilatory cycle. Measurements and Main Results: The comparison between the continuous cardiac output measurement methods TDCCO versus PCCO showed a bias of −0.12 L/min, between TDCCO versus NICO −0.17 L/min, and between PCCO versus NICO −0.44 L/min. The comparison to the reference technique between TDBCOpa versus TDCCO revealed a bias of −0.28 L/min, between TDBCOpa versus PCCO −0.40 L/min, and between TDBCOpa versus NICO −0.64 L/min. Conclusions: The results of this clinical investigation show agreement between TDCCO and PCCO to satisfy clinical requirements in a setting of postoperative patients after cardiac surgery. In contrast, the NICO monitor is of very limited use in these patients. © 2003 Elsevier Inc. All rights reserved.