Background: An ideal arterial pressure monitoring system for perioperative care is required to be accurate, noninvasive, continuous, and risk free. Although several continuous noninvasive arterial pressures (CNAP) are determined on the finger, a new wrist CNAP monitoring system was developed. This prospective study was designed as a randomized-controlled trial to assess its validity in comparison with invasive arterial pressure (IAP) monitoring.
Patients and methods: Sixty patients undergoing elective surgery under general anesthesia were enrolled. One-side arm in each patient was selected randomly to assess the new monitoring system placed on the wrist; an arterial catheter for IAP was inserted at the radial artery in the contralateral arm. The Bland-Altman method for repeated measurements was used to assess agreement between measurement methods by the levels of agreement according to the American Association for the Advancement of Medical Instrumentation standards.
Results: A total of 6600 valid pressure readings were obtained from 60 patients, including 3000 beat data and 3600 pulse wave data, respectively. The mean differences in wrist CNAP versus IAP for beat data were as follows: systolic arterial pressure (SAP): -2.09±5.39 mmHg; mean arterial pressure (MAP): 0.27±3.64 mmHg; diastolic arterial pressure (DAP): and 2.63±6.44 mmHg. For pulse wave data, the mean difference (SD) values were as follows: SAP: -2.06±6.51 mmHg; MAP: 0.50±4.36 mmHg; and DAP: 3.06±6.81 mmHg. Percentage errors were less than 28.3%. Levels of agreements were detected to be -12.65-8.47 for SAP, -6.86-7.40 for MAP, and -9.99-15.26 for DAP.
Conclusion: The new wrist CNAP monitoring system showed an acceptable agreement and interchangeability with the IAP.