The Entropy Module® and Bispectral Index® as Guidance for Propofol-Remifentanil Anaesthesia in Combination with Regional Anaesthesia Compared with a Standard Clinical Practice Group

<jats:p> This study was designed to investigate the impact of the Entropy Module® and Bispectral Index® (BIS) monitoring on drug consumption and recovery times compared with standard anaesthetic practice in patients undergoing orthopaedic surgery using a combination of regional and general anaesthesia as performed by an experienced anaesthesiologist. We hypothesised that electroencephalogram monitoring would lead to a lower drug consumption as well as shorter recovery times. </jats:p><jats:p> With institutional review board approval and written informed consent, 90 adult patients undergoing surgery to the upper or lower extremity received regional anaesthesia for post- and intraoperative pain control and were randomised to receive general anaesthesia by propofol/remifentanil infusion controlled either solely by clinical parameters or by targeting Entropy or BIS values of 50. Recovery times and drug consumption were recorded. </jats:p><jats:p> Data from 79 patients were analysed. Compared with standard practice, patients with Entropy or BIS monitoring showed a similar propofol consumption (standard practice 101±22 μg/kg/minute, Entropy 106±24 μg/kg/minute, BIS 104±20 μg/kg/minute) and showed similar Aldrete scores (10/10) one minute after extubation: 9.1∓0.3, 9.2±0.6 and 9.3±0.5, respectively. Time points of extubation were 7.3±2.9 minutes, 9.2∓3.9 minutes and 6.8±2.9 minutes, respectively, demonstrating a significant difference between Entropy and BIS (P=0.023). </jats:p><jats:p> Compared with standard practice, targeting an Entropy or BIS value of 50 did not result in a reduction of propofol consumption during general anaesthesia combined with regional anaesthesia as performed by an experienced anaesthesiologist in orthopaedic patients. </jats:p>