Disagreement between fourth generation FloTrac and LiDCOrapid measurements of cardiac output and stroke volume variation during laparoscopic colectomy.

STUDY OBJECTIVE: To determine the agreement between cardiac output (CO) and stroke volume variation (SVV) measured simultaneously by the fourth generation FloTrac/Vigileo system and LiDCOrapid system during pneumoperitoneum in patients undergoing laparoscopic colectomy.

DESIGN: Retrospective observational study.

SETTINGS: Operating room in a general hospital.

PATIENTS: Ten patients (American Society of Anesthesiologist 1 or 2) without preoperative anemia.

INTERVENTIONS: A 22-gauge catheter was inserted in the radial artery after induction of anesthesia. The arterial line was split to monitor CO and SVV simultaneously with the LiDCOrapid and fourth generation FloTrac/Vigileo systems. All data were downloaded from each system after surgery and simultaneous paired COFloTrac , COLiDCO and SVVFloTrac , SVVLiDCO values estimated every 1 minute during the pneumoperitoneum were analyzed.

MEASUREMENTS: To assess the agreement after carbon dioxide insufflation, a scatter 4-quadrant plot was generated using paired ΔCO values (changes in COFloTrac and COLiDCO just before pneumoperitoneum and 3 minutes after the induction of pneumoperitoneum). For data in which SVVFloTrac was >9% but <16% and cardiac index measured by FloTrac/Vigileo was <2.5 L/min per m2 during stable pneumoperitoneum (the period from 5 minutes after Trendelenburg position until discontinuation of pneumoperitoneum), simultaneously measured paired SVVFloTrac and SVVLiDCO were plotted every 1 minute using the Bland-Altman method.

MAIN RESULTS: A concordance ratio for changes in CO after the induction of pneumoperitoneum was 83% in 4-quadrant plot. During stable pneumoperitoneum, 702 paired SVVFloTrac and SVVLiDCO matched the criteria. These data sets were plotted by the Bland-Altman method and the bias and 95% limit of agreement of SVV were 2.01 and -2.63% to 6.65%, respectively, with 38% percentage error. The regression equation was SVVLiDCO = 0.98 × SVVFloTrac - 1.73 with Pearson correlation coefficient of 0.55.

CONCLUSIONS: Our study showed disagreement between the 2 methods and the hemodynamic parameters measured by one of the two devices should be interpreted with caution before therapeutic interventions.