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

- The latest FloTrac and LiDCOrapid were compared during pneumoperitoneum.
- Cardiac output after induction of pneumoperitoneum disagreed with the 2 devices.
- Stroke volume variation during stable pneumoperitoneum also disagreed.
- The regression equation was SVVLiDCO = 0.98 × SVVFloTrac − 1.73.
- Parameters measured by one of the two devices should be interpreted with caution.

Study objectiveTo 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.DesignRetrospective observational study.SettingsOperating room in a general hospital.PatientsTen patients (American Society of Anesthesiologist 1 or 2) without preoperative anemia.InterventionsA 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.MeasurementsTo 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 resultsA 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.ConclusionsOur 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.