Noninvasive continuous arterial pressure monitoring during anesthesia induction in patients undergoing cardiac surgery

Objective: In this study we compared noninvasive arterial pressure measurement using ClearSight (TM) vascular-unloading-technique (Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurement during induction of anesthesia undergoing mayor cardiac surgery. Design: Prospective, monocentric. Setting: University hospital. Participants: 54 patients undergoing mayor cardiac surgery. Interventions: During induction all patients were simultaneously monitored with invasive (reference method) and noninvasive arterial pressure measurement (test-method) over a mean time period of 27 minutes. Measurements and Main Results: We observed slightly lower systolic and mean arterial pressures noninvasive than invasive. For systolic arterial pressure the mean of the differences was -18,05 mmHg (p < 0,05, SD +/- 16,78 mmHg), the mean arterial pressure MAP -5,47 mmHg (p < 0,05, SD +/- 11,08 mmHg) and for diastolic pressure -1,09 mmHg (p < 0,05, SD +/- 11,15 mmHg),. The mean of the differences in heartrate was 1,15 (p < 0,05, SD +/- 6,9 mmHg). When considering all measured values of the invasively measured MAP and the ClearSight (TM)-MAP at the same timestamp over the recording interval, an almost identical progress can be seen that indicates a sufficient mapping of the hemodynamic changes. The percentage error for mean arterial, systolic and diastolic pressure measured by ClearSight (TM) amounts to 25,95 %, 26,77 % and 34,16 %, respectively. Conclusions: We conclude that ClearSight (TM) is a good option for hemodynamic monitoring during induction of anesthesia. Taking into account the limitations, non-invasive arterial blood pressure measurement offers sufficient security to safely initiate anesthesia, especially when MAP is of particular interest. The use of non-invasive arterial blood pressure measurement with ClearSight (TM) during induction of anesthesia in patients scheduled for major cardiac surgery is reliable and easy to use.