Influence of non-invasive blood pressure measurement intervals on the occurrence of intra-operative hypotension

• Type of Material: Article
• Authors: Grant H. Kruger, University of Michigan; Amy Shanks, University of Michigan; Sachin Kheterpal, University of Michigan; Tyler Tremper, University of Michigan; Chi-Jung Chiang, Luren Precision Co.; Robert E. Freundlich, Vanderbilt University; James M. Blum, Emory University; Albert J. Shih, University of Michigan; Kevin K. Tremper, University of Michigan
• Language: English
• Date: 2018-08-01
• Publisher: Springer (part of Springer Nature): Springer Open Choice Hybrid Journals
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2017, Springer Science+Business Media B.V.
• Final Published Version (URL): http://dx.doi.org/10.1007/s10877-017-0065-4
• Title of Journal or Parent Work: Journal of Clinical Monitoring and Computing
• ISSN: 1387-1307
• Volume: 32
• Issue: 4
• Start Page: 699
• End Page: 705
• Grant/Funding Information: This work was supported from discretionary research funds from the Department of Anesthesiology at the University of Michigan.
• Keywords: Science & Technology; SYSTEMS; Physiologic monitoring; NONCARDIAC SURGERY; GAPS; MONITOR; Non-invasive blood pressure; Anesthesiology; Measurement gaps; DEFINITION; Life Sciences & Biomedicine; ALARMS; Intra-operative hypertension
• Research Categories: Engineering, Biomedical; Health Sciences, Medicine and Surgery

Abstract

The American Society of Anesthesiologists Standards for Basic Monitoring recommends blood pressure (BP) measurement every 5 min. Research has shown distractions or technical factors can cause prolonged measurement intervals exceeding 5 min. We investigated the relationship between prolonged non-invasive BP (NIBP) measurement interval and the incidence of hypotension, detected post-interval. Our secondary outcome was to determine independent predictors of these prolonged NIBP measurement intervals. Retrospective data were analyzed from 139,509 general anesthesia cases from our institution’s Anesthesia Information Management System (AIMS). Absolute hypotension (AH) was defined a priori as a systolic BP < 80 mmHg and relative hypotension (RH) was defined as a 40% decrease in systolic BP from the preoperative baseline. Odds ratios (OR) with 95% confidence intervals and Pearson’s Chi square Test reported the association of prolonged NIBP measurement intervals on hypotension detected post-NIBP measurement interval. Logistic regression models were developed to determine independent predictors of NIBP measurement intervals. The analysis revealed that NIBP measurement intervals greater than 6 and 10 min are associated with an approximately four times higher incidence of a patient transitioning into hypotension (AH/RH > 6 min OR 4.0 / 3.6; AH/RH > 10 min OR 4.3 / 3.9; p < 0.001). A key finding was that the “> 10-minute AH model” indicated that age 41–80, increased co-morbidity profile, obesity and turning (repositioning) of the operative room table were significant predictors of prolonged NIBP measurement intervals (p < 0.001). While we do not suggest NIBP measurement intervals cause hypotension, intervals greater than 6 and 10 min are associated with a fourfold increase in the propensity of an undetected transition into both RH or AH. These data support current monitoring guidelines.