Assessment of Correlation Between Brain Function Index and Three Common Sedation Scales in Intensive Care Unit Patients

Objectives: This study aimed to evaluate the correlation of the Brain Function Index (BFI) with three criteria of consciousness (Glasgow, Richmond, and FOUR score) in the intensive care unit. Methods: We enrolled patients aged over 15 years who required no muscle relaxants and had no hearing and visual impairment, mental retardation, mental disorder, hemodynamic instability (MAP < 60 mmHg), and hypoxia (SpO2 < 90%), as well as patients with no brain electrical activity disorders such as epilepsy and focal brain disease, and those who had not undergone anesthesia and surgery for the past 24 hours. Results: All ICU patients were enrolled in the study in the autumn and winter based on inclusion and exclusion criteria (n = 85). During 24 hours, BFI and three clinical criteria of sedation and consciousness including RASS, GCS, and FOUR score were assessed three times with a minimum of four-hour intervals. Among the patients, 45 (52.9%) were males, and 40 (47.1%) were females; 24 (28.2%) patients were under 40 years of age, 13 (15.3%) patients were between 41 and 60 years old, and 48 (56.5%) patients were over 61 years old. There was a significant positive relationship between the BFI score of ICU patients and the score of patient consciousness based on RASS, FOUR score, and GCS. The correlation of BFI with the FOUR score was higher than those with the other two criteria. Conclusions: Objective criteria for assessing the consciousness level such as BFI are sufficiently accurate and can be used instead of clinical criteria to assess the level of consciousness in special wards.