Assessing sedation in critically ill children by bispectral index, auditory-evoked potentials and clinical scales.

OBJECTIVE: To evaluate the correlation and agreement between the bispectral index (BIS), middle latency auditory-evoked potential index (AEP index), Ramsay scale (RS) and COMFORT scale (CS) for evaluation of the level of sedation in critically ill children.
DESIGN: Prospective observational study.
SETTING: Pediatric critical care unit. PATIENTS: Seventy-seven critically ill children receiving sedation and mechanical ventilation. MEASUREMENTS AND
RESULTS: Simultaneous recording of BIS, AEP index, RS and CS were performed once a day, for a maximum of 5 days. Two levels of sedation were categorized: light-moderate versus deep-very deep. Correlations between methods were determined using Spearman rank correlation test and the agreement using Cohen's Kappa test. The correlation and agreement between the four methods was moderate-to-good. Correlation was not found in paralyzed children. There was no correlation between the four methods and the heart rate or blood pressure, or with the type or dose of sedative medication. Receiver-operating characteristic (ROC) analysis revealed best discrimination between light-moderate and deep-very deep sedation at BIS and AEP index values of 63.5 and 33.5 when the level of sedation was classified by the RS, and at BIS and AEP index values of 67 and 37.5, respectively, when the level of sedation was classified by the CS.
CONCLUSION: There is a moderate-to-good correlation and agreement of BIS and AEP index with the clinical scales in critically ill children without neuromuscular blockade. BIS and AEP index could be useful to evaluate the level of sedation in critically ill children with and without neuromuscular blockade.