Postoperative Delirium in a Substudy of Cardiothoracic Surgical Patients in the BAG-RECALL Clinical Trial

Abstract

Background-Postoperative delirium in the intensive care unit (ICU) is a frequent complication after cardiac or thoracic surgery and is associated with increased morbidity and mortality.

Preventing Delirium After Cardiothoracic Surgery

“…3 Is there anything that we as anesthesiologists can do to decrease the incidence of delirium? 5 Although Whitlock et al 4 also found a trend toward lower delirium incidence in patients enrolled in the BIS arm, neither the average ETAC, nor cumulative anesthetic exposure (e.g., MAC-hours), 8 nor the occurrence of deep anesthesia (BIS <20) is given for the BIS versus ETAC titration arms. In this issue of Anesthesia & Analgesia, Whitlock et al 4 examine whether using a BIS monitor decreases the incidence of delirium in cardiothoracic surgery patients.…”

“…1 Today, the term postoperative delirium is often used to describe the mental state of many of these patients. Furthermore, one could argue that the difference in average ETAC (0.79 ± 0.12 vs 0.85 ± 0.11) between delirious and nondelirious patients is not clinically meaningful.Surprisingly, Whitlock et al 4 show that age-adjusted average ETAC during maintenance was inversely correlated with delirium; patients who received less inhaled agents were more likely to develop delirium. It is a common (and likely underrecognized) complication correlated with adverse outcomes including decreased quality of life and increased hospital and 6-month mortality.…”

“…Surprisingly, Whitlock et al 4 show that age-adjusted average ETAC during maintenance was inversely correlated with delirium; patients who received less inhaled agents were more likely to develop delirium. At first glance, this finding appears to contradict the results of the previous studies, which found that BIS usage was associated with decreased anesthetic dosage and lower delirium rates.…”

“…Delirium is a syndrome of waxing and waning mental status changes and alterations in the level of consciousness. In this issue of Anesthesia & Analgesia, Whitlock et al 4 examine whether using a BIS monitor decreases the incidence of delirium in cardiothoracic surgery patients. 2 More recently, postoperative delirium has also been associated with cognitive decline during the first year after cardiac surgery.…”

“…Processed electroencephalography (EEG) (e.g., Bispectral Index, BIS) is a controversial tool in anesthesiology but may be a useful instrument for preventing postoperative delirium. 4 If that is the case, can we really posit that BIS offers more value than ETAC for preventing delirium? They report a trend toward less delirium in the BIS-guided anesthetic group versus the end-tidal anesthetic concentration (ETAC)-guided group (18.8% vs 28%), although this difference was not statistically significant (P = 0.058) despite adequate statistical power.…”