Impact of continuous non-invasive blood pressure monitoring on hemodynamic fluctuation during general anesthesia: a randomized controlled study.

This study assessed the ability of a continuous non-invasive blood pressure (BP) monitoring system to reduce intra-anesthetic hemodynamic fluctuation compared with intermittent BP cuff measurement. Forty patients undergoing total knee arthroplasty under general anesthesia were enrolled and randomly divided into two groups (Control and CS group). BP management was performed using the same protocol with BP measured by intermittent BP cuff in the Control and that by continuous non-invasive BP monitoring in the CS group. We assessed the accuracy and precision of the continuous non-invasive BP monitoring compared with BP cuff measurement using Bland-Altman, four-quadrant plot, and polar-plot analyses. Additionally, the occurrence of hypotension and hypertention during general anesthesia was compared between the two groups. The continuous non-invasive BP monitoring showed excellent accuracy of - 1.1 ± 8.1 mmHg during surgery and an acceptable trending ability with a concordance rate of 95.1% according to the four-quadrant plot analysis and an angular concordance rate of 86.7% by polar-plot analysis. Hypotension was less common in the CS group during induction of anesthesia (p = 0.002) and surgery (p = 0.008). Hypertension occurred more frequently in the Control group during emergence from anesthesia (p = 0.037). The duration of hemodynamic stability (systolic BP 80-110% of baseline) intraoperatively was longer in the CS group than in the Control group (87.7 vs. 61.9%; p < 0.001). Accuracy and trending ability of the continuous non-invasive BP monitoring was clinically acceptable, and lead to hemodynamic stability and reduction of intra-anesthetic hypotension and hypertension intraoperatively.