Table 3.
Cardiac index measurements by FloTrac compared to bolus thermodilution technique with a pulmonary artery catheter
| FloTrac | All n = 579 |
Phase 1 n = 24 |
Phase 2 n = 27 |
Phase 3 n = 85 |
Phase 4 n = 104 |
|---|---|---|---|---|---|
|
Bias (L min−1 m−2) (95% CI) |
0.01 (− 0.05 to 0.06) |
− 0.17 (− 0.44 to 0.10) |
− 0.01 (− 0.27 to 0.26) |
− 0.15 (− 0.30 to 0.00) |
− 0.25 (− 0.39 to − 0.11) |
|
LOA lower (L min−1 m−2) (95% CI) |
− 1.27 (− 1.56 to − 0.98) |
− 1.28 (− 1.8 to − 0.77) |
− 1.32 (− 1.85 to − 0.78) |
− 1.52 (− 1.99 to − 1.06) |
− 1.78 (− 2.37 to − 1.18) |
|
LOA upper (L min−1 m−2) (95% CI) |
1.29 (1.0 to 1.58) |
0.93 (0.41 to 1.45) |
1.26 (0.72 to 1.79) |
1.08 (0.61 to 1.54) |
1.27 (0.67 to 1.87) |
|
Percentage error (95%CI) |
56.8% (44.4 to 69.2) |
47.2% (32.8 to 61.6) |
53.7% (32.7 to 74.7) |
65.7% (48.1 to 83.3) |
61.9% (30.4 to 93.4) |
|
Regression coefficient (L min−1 m−2) (95% CI) |
− 0.19 (− 0.27 to − 0.10) |
− 0.12 (− 0.67 to 0.43) |
− 0.26 (− 0.98 to 0.47) |
− 0.06 (− 0.37 to 0.26) |
− 0.31 (− 0.52 to − 0.09) |
| Error grid | |||||
| Zone 1 | 39.3% | – | – | 36.8% | 45.5% |
| Zone 2 | 12.2% | – | – | 11.8% | 8.0% |
| Zone 3 | 35.4% | – | – | 31.6% | 38.6% |
| Zone 4 | 13.0% | – | – | 19.7% | 8.0% |
Phase 1 is before induction of anesthesia, phase 2 is during the construction of the proximal anastomoses to the ascending aorta, phase 3 is distal coronary anastomoses, phase 4 is postoperatively in the intensive care unit before extubation. Error grid analysis was not made for the phases 1 and 2 because of the small number of measurements. n number of CI measurements during the phase. LOA limits of agreement