Non-invasive continuous arterial pressure and cardiac index monitoring with Nexfin after cardiac surgery
British Journal of Anesthesia, 07/03/2012
Fischer MO et al. – The Nexfin device is safe, convenient, and reliable in measuring continuous non–invasive arterial pressure but not interchangeable with transpulmonary thermodilution to monitor cardiac index (CI).Methods
- Fifty consecutive adult subjects were prospectively enrolled at admission to the intensive care unit after conventional cardiac surgery and investigated hourly from T0 to T4.
- Simultaneous comparative systolic, diastolic, and mean arterial pressures and cardiac index (CI) data points were collected from an invasive radial artery catheter, transpulmonary thermodilution catheter, and the Nexfin device.
- Correlations were determined by linear regression.
- The Bland–Altman analysis was used to compare bias, precision, and limits of agreement.
- Six (12%) subjects were excluded from the analysis because of the inability to obtain a reliable photoplethysmographic signal.
- No complications were observed.
- A significant relationship was found between absolute values of photoplethysmographic and radial systolic (r2=0.56, P<0.001), diastolic (r2=0.61, P<0.001), and mean (r2=0.77, P<0.001) arterial pressures.
- A significant relationship was also found between transpulmonary thermodilution and Nexfin CI absolute values (r2=0.33, P<0.001).
- Bias, precision, and limits of agreement between the mean photoplethysmographic and radial arterial pressures were 4.6 (95% confidence interval: 3.7–5.5), 6.5, and -17.3 to 8.1mmHg, respectively.
- The percentage error between transpulmonary thermodilution and the Nexfin for CI measurement was 50%.