Accuracy of the ClearSight™ system in patients undergoing abdominal aortic aneurysm surgery.

Purpose: The ClearSight™ device monitors continuous pressure and cardiac output via pulse contour analysis. ClearSight™, however, may not be reliable in patients with reduced peripheral perfusion caused by high peripheral resistance. This study aimed to elucidate the accuracy and trending ability of ClearSight™ in patients undergoing abdominal aortic aneurysm (AAA) surgery by comparing the ClearSight-derived cardiac index (CI) with that measured using three-dimensional echocardiography (CI).

Methods: The study included 20 patients who underwent elective AAA surgery. CI and CI were measured simultaneously at eight time points during the surgery. Trending ability was investigated after aortic clamping and unclamping. We used CI as the reference method.

Results: Bland-Altman analysis showed a wide limit of agreement between CI and CI (percentage error 41.3%). Subgroup analysis showed a lower percentage error (33.2%) in patients with CI ≥ 2.5 L/min/m. The cubic splines related to the CI and CI discrepancy were negatively sloped, indicating that CI had significant influence on the CI discrepancy (p < 0.001). Four-quadrant plot analysis showed that the tracking ability of ClearSight™ after aortic clamping and declamping were clinically unacceptable (81.3% and 78.6%, respectively). Also, the polar plot analysis showed that the concordance rate of ClearSight™ after aortic clamping and declamping were clinically unacceptable (58.3% and 66.7%, respectively).

Conclusions: ClearSight™ was not sufficiently accurate in patients undergoing AAA surgery. The tracking ability of ClearSight™ after aortic clamping was below the acceptable limit.