Real-Time Monitoring of Blood Pressure Using Digitalized Pulse Arrival Time Calculation Technology for Prompt Detection of Sudden Hypertensive Episodes During Laryngeal Microsurgery: Retrospective Observational Study.
BACKGROUND
Laryngeal microsurgery (LMS) is often accompanied by a sudden increase in blood pressure (BP) during surgery because of 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 to 5 min.


OBJECTIVE
This study 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 the ECG and the maximum slope on the PPG. Mean PAT values before and after BP increase were compared. PPG-related parameters and the correlations between changes in these variables were calculated.


RESULTS
BP surged because of laryngoscopic manipulation (mean systolic BP [SBP] from 115.3, SD 21.4 mmHg, to 159.9, SD 25.2 mmHg; P<.001), whereas PAT decreased significantly (from mean 460.6, SD 51.9 ms, to 405.8, SD 50.1 ms; P<.001) in most of the cases. The change in SBP showed a significant correlation with the inverse of the PAT (r=0.582; P<.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 SBP, 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 BP surges during laryngoscopic manipulations in a noninvasive manner.
['Park|Yong-Seok|YS|0000-0002-3752-2211', 'Kim|Sung-Hoon|SH|0000-0001-5215-7585', 'Lee|Yoon Se|YS|0000-0001-6534-5753', 'Choi|Seung-Ho|SH|0000-0001-9109-9621', 'Ku|Seung-Woo|SW|0000-0002-3865-4654', 'Hwang|Gyu-Sam|GS|0000-0002-3627-1107']
D001794:Blood Pressure D001795:Blood Pressure Determination D005260:Female D006339:Heart Rate D006801:Humans D006973:Hypertension D007830:Larynx D008297:Male D008866:Microsurgery D008875:Middle Aged D012189:Retrospective Studies
blood pressure pulse larynx photoplethysmography