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The Feasibility of a Completely Automated Total IV Anesthesia Drug Delivery System for Cardiac Surgery

Zaouter, Cedrick MD, MSc; Hemmerling, Thomas M. MD; Lanchon, Romain MD; Valoti, Emanuela MD; Remy, Alain MD; Leuillet, Sébastien MSc; Ouattara, Alexandre MD, PhD

doi: 10.1213/ANE.0000000000001152
Technology, Computing, and Simulation: Original Clinical Research Report

BACKGROUND: In this pilot study, we tested a novel automatic anesthesia system for closed-loop administration of IV anesthesia drugs for cardiac surgical procedures with cardiopulmonary bypass. This anesthesia drug delivery robot integrates all 3 components of general anesthesia: hypnosis, analgesia, and muscle relaxation.

METHODS: Twenty patients scheduled for elective cardiac surgery with cardiopulmonary bypass were enrolled. Propofol, remifentanil, and rocuronium were administered using closed-loop feedback control. The main objective was the feasibility of closed-loop anesthesia defined as successful automated cardiac anesthesia without manual override by the attending anesthesiologist. Secondary qualitative observations were clinical and controller performances. The clinical performance of hypnosis control was the efficacy to maintain a bispectral index (BIS) of 45. To evaluate the hypnosis performance, BIS values were stratified into 4 categories: “excellent,” “good,” “poor,” and “inadequate” hypnosis control defined as BIS values within 10%, ranging from 11% to 20%, ranging from 21% to 30%, or >30% of the target value, respectively. The clinical performance of analgesia was the efficacy to maintain NociMap values close to 0. The analgesia performance was assessed classifying the NociMap values in 3 pain control groups: −33 to +33 representing excellent pain control, −34 to −66 and +34 to +66 representing good pain control, and −67 to −100 and +67 to +100 representing insufficient pain control. The controller performance was calculated using the Varvel parameters.

RESULTS: Robotic anesthesia was successful in 16 patients, which is equivalent to 80% (97.5% confidence interval [CI], 53%–95%) of the patients undergoing cardiac surgery. Four patients were excluded from the final analysis because of technical problems with the automated anesthesia delivery system. The secondary qualitative observations revealed that the clinical performance of hypnosis allowed an excellent and good control during 70% (97.5% CI, 63%–76%) of maintenance time and an insufficient clinical performance of analgesia for only 3% (97.5% CI, 1%–6%) of maintenance time.

CONCLUSIONS: The completely automated closed-loop system tested in this investigation could be used successfully and safely for cardiac surgery necessitating cardiopulmonary bypass. The results of the present trial showed satisfactory clinical performance of anesthesia control.

Published ahead of print January 25, 2016.

From the *CHU de Bordeaux, Service d Anesthésie-Réanimation II, Bordeaux, France; Division of Experimental Surgery, Department of Anaesthesia, Arnold and Blema Steinberg Simulation Centre, McGill University, Montreal, Canada; Servizio di Anestesia Rianimazione e terapia intensiva, Università degli Studi di Pavia, Dip. Scienze Clinico-Chirurgiche Diagnostiche e Pediatriche, Unità di Anestesiologia - Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; and §Biofortis, Mérieux NutriSciences Company, Saint-Herblain, France.

Published ahead of print January 25, 2016.

Accepted for publication November 23, 2015.

Funding: This study was supported solely by the Department of Anesthesia and Critical Care of the CHU de Bordeaux, Service d’anesthésie-Réanimation II, F-33000 Bordeaux, France.

The authors declare no conflicts of interest.

This report was previously presented, in part, at the 2014 Annual Meeting of French Society of Anaesthesia and Intensive Care, September 18–21, 2014, Paris, France.

Reprints will not be available from the authors.

Address correspondence to Cedrick Zaouter, MD, MSc, CHU de Bordeaux, Service d Anesthésie-Réanimation II, F-33000 Bordeaux, Ave. de Magellan, Pessac, France. Address e-mail to

© 2016 International Anesthesia Research Society