Bispectral Index asymmetry and COMFORT score in paediatric intensive care patients

Abstract

Background. The Bispectral Index (BIS) monitor has been suggested as a potential tool to measure depth of sedation in paediatric intensive care unit (PICU) patients. The primary aim of our observational study was to assess the difference in BIS values between the left and right sides of the brain. Secondary aims were to compare BIS and COMFORT score and to assess change in BIS with tracheal suctioning. Methods. Nineteen ventilated and sedated PICU patients had paediatric BIS sensors applied to either side of their forehead. Each patient underwent physiotherapy involving tracheal suctioning. Their BIS data and corresponding COMFORT score, assessment as by their respective nurses, were recorded before, during, and after physiotherapy. Results. Seven patients underwent more than one physiotherapy session; therefore, 28 sets of data were collected. The mean BIS difference values (and 95% CI) between left BIS and right BIS for pre-, during, and post-physiotherapy periods were 9.2 (5.9-12.5), 15.8 (11.9-19.7), and 7.5 (5.2-9.7), respectively. Correlation between mean BIS, left brain BIS, and right brain BIS to COMFORT score was highly significant (P<0.001 for all three) during the pre- and post-physiotherapy period, but less so during the stimulated physiotherapy period (P=0.044, P=0.014, and P=0.253, respectively). Conclusions. A discrepancy between left and right brain BIS exists, especially when the patient is stimulated. COMFORT score and BIS correlate well between light and moderate sedation. © The Board of Management and Trustees of the British Journal of Anaesthesia 2008. All rights reserved.