Accepted for/Published in: Journal of Medical Internet Research
Date Submitted: Dec 15, 2018
Date Accepted: Feb 9, 2020
Real-time monitoring of blood pressure using the digitalized pulse arrival time calculation technology for prompt detection of sudden hypertensive episode during laryngeal microsurgery
ABSTRACT
Background:
Laryngeal microsurgery (LMS) is often accompanied by a sudden increase in blood pressure (BP) during surgery due to stimulation around the larynx. This sudden change in the hemodynamic status is not immediately reflected in a casual cuff-type measurement that takes intermittent readings every 3-5 minutes.
Objective:
We aimed to investigate the potential of pulse arrival time (PAT) as a marker for a BP surge which usually occurs in patients undergoing LMS.
Methods:
Intermittent measurements of BP and electrocardiogram (ECG) and photoplethysmogram (PPG) signals were recorded during LMS. PAT was defined as the interval between the R-peak on ECG and the maximum slope on the PPG. Mean PAT before and after BP increase were compared. PPG-related parameters and the correlations between changes in these variables were calculated.
Results:
BP surged due to laryngoscopic manipulation (systolic BP, 115.3±21.4 mmHg to 159.9±25.2 mmHg, P<0.001), whereas PAT decreased significantly (460.6±51.9 ms to 405.8±50.1 ms, P<0.001) in most of the cases. The change in systolic BP (SBP) showed a significant correlation with the inverse of the PAT (r=0.582, P<0.001). Receiver-operating characteristic curve analysis indicated that an increase of 11.5% in the inverse of the PAT could detect a 40% increase in systolic BP, and the area under the curve was 0.814.
Conclusions:
During LMS, where invasive arterial catheterization is not always possible, PAT shows good correlation with SBP and may therefore have the potential to identify abrupt blood pressure surges during laryngoscopic manipulations in a non-invasive manner.
Citation
