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Anesthesia Information Management System-Based Near Real-Time Decision Support to Manage Intraoperative Hypotension and Hypertension

Nair, Bala G. PhD*; Horibe, Mayumi MD; Newman, Shu-Fang MS*; Wu, Wei-Ying PhD; Peterson, Gene N. MD, PhD*; Schwid, Howard A. MD*

doi: 10.1213/ANE.0000000000000027
Economics, Education, and Policy: Research Report

BACKGROUND: Intraoperative hypotension and hypertension are associated with adverse clinical outcomes and morbidity. Clinical decision support mediated through an anesthesia information management system (AIMS) has been shown to improve quality of care. We hypothesized that an AIMS-based clinical decision support system could be used to improve management of intraoperative hypotension and hypertension.

METHODS: A near real-time AIMS-based decision support module, Smart Anesthesia Manager (SAM), was used to detect selected scenarios contributing to hypotension and hypertension. Specifically, hypotension (systolic blood pressure <80 mm Hg) with a concurrent high concentration (>1.25 minimum alveolar concentration [MAC]) of inhaled drug and hypertension (systolic blood pressure >160 mm Hg) with concurrent phenylephrine infusion were detected, and anesthesia providers were notified via “pop-up” computer screen messages. AIMS data were retrospectively analyzed to evaluate the effect of SAM notification messages on hypotensive and hypertensive episodes.

RESULTS: For anesthetic cases 12 months before (N = 16913) and after (N = 17132) institution of SAM messages, the median duration of hypotensive episodes with concurrent high MAC decreased with notifications (Mann Whitney rank sum test, P = 0.031). However, the reduction in the median duration of hypertensive episodes with concurrent phenylephrine infusion was not significant (P = 0.47). The frequency of prolonged episodes that lasted >6 minutes (sampling period of SAM), represented in terms of the number of cases with episodes per 100 surgical cases (or percentage occurrence), declined with notifications for both hypotension with >1.25 MAC inhaled drug episodes (δ = −0.26% [confidence interval, −0.38% to −0.11%], P < 0.001) and hypertension with phenylephrine infusion episodes (δ = −0.92% [confidence interval, −1.79% to −0.04%], P = 0.035). For hypotensive events, the anesthesia providers reduced the inhaled drug concentrations to <1.25 MAC 81% of the time with notifications compared with 59% without notifications (P = 0.003). For hypertensive episodes, although the anesthesia providers’ reduction or discontinuation of the phenylephrine infusion increased from 22% to 37% (P = 0.030) with notification messages, the overall response was less consistent than the response to hypotensive episodes.

CONCLUSIONS: With automatic acquisition of arterial blood pressure and inhaled drug concentration variables in an AIMS, near real-time notification was effective in reducing the duration and frequency of hypotension with concurrent >1.25 MAC inhaled drug episodes. However, since phenylephrine infusion is manually documented in an AIMS, the impact of notification messages was less pronounced in reducing episodes of hypertension with concurrent phenylephrine infusion. Automated data capture and a higher frequency of data acquisition in an AIMS can improve the effectiveness of an intraoperative clinical decision support system.

Published ahead of print November 15, 2013

From the *Department of Anesthesiology and Pain Medicine, University of Washington; Department of Anesthesiology, VA Puget Sound Health Care System, Seattle, Washington; and Department of Applied Mathematics, National Dong Hwa University, Hualien, Taiwan.

Accepted for publication September 27, 2013.

Published ahead of print November 15, 2013

Funding: This research was partly supported by Laura Cheney Patient Safety Grant provided by the University of Washington.

The authors declare no conflicts of interest.

Reprints will not be available from the authors.

Address correspondence to Bala G. Nair, PhD, Department of Anesthesiology and Pain Medicine, University of Washington, BB-1469 Health Sciences Bldg., Mail Box: 356540, 1959 NE Pacific St., Seattle, WA 98195. Address e-mail to

© 2014 International Anesthesia Research Society