Correlation of post-operative delirium with bis guided depth of anesthesia in adult cardiac surgical patients

Background: Following cardiac surgery, postoperative delirium is a common acute neurocognitive illness with serious repercussions for patients. BIS is a simple approach for continuously measuring brain activity when anesthetic, hypnotic, or sedative medications are administered. BIS monitoring is thought to be a more trustworthy approach for determining awareness levels. As a result, we conducted this study to see if the depth of anesthesia, as measured by the bispectral index, impacts post-operative neural cognitive performance in patients undergoing cardiac surgery.
Settings and Design: It is a descriptive and observational study carried out in 90 patients
planned for cardiac surgeries were divided into 2 groups of 45 patients each as Group A and Group B. Group A with lower BIS (less than 60) and group B with higher BIS (more than 60).According to the Richmond agitation sedation scale, delirium was diagnosed (RASS).
Results: Delirium was seen among 4.4% of group 1 and 2.2% of group 2 participants when assessed by RASS scale at 30 minutes after surgery. 68.9% of group 1 and 22.2% of group 2 participants had delirium at 4hrs after surgery. Even at next day morning delirium was assessed among both the groups, 44 participants of group 1 and 18 of group 2 participants had delirium next day morning. The next day evening delirium was seen in all the study participants among group 1 where as in group 2, 22 participants had delirium.
Conclusions: During cardiac procedures, anesthesia regulated by bispectral index monitoring reduces the risk of post-operative delirium and makes titration of anesthetic agents easier.