Effects of closed-loop intravenous anesthesia guided by Bispectral Index in adult patients on emergence delirium: a randomized controlled study.

BACKGROUND

Emergence delirium (ED) is an acute change in cognition after general anesthesia (GA) occurring in operative room, recovery room or in postanesthesia care. The automated propofol-remifentanil titration by Bispectral Index (BIS) (AutoTIVA) avoids period of deep (BIS<40) anesthesia and could potentially decrease the ED. The aim of this study was to evaluate ED in surgical patients under AutoTIVA, manual titration of propofol-remifentanil (ManualTIVA) or volatile BIS-guided GA. Moreover, we aimed to evaluate age-related postoperative Mini-Mental State Examination (MMSE) changes.

METHODS

One hundred and thirty-two adult patients scheduled for elective urologic surgery were randomized in: AutoTIVA, desflurane (DES), sevoflurane (SEVO), ManualTIVA anesthesia. The MMSE was performed before GA and 15 minutes after tracheal extubation.

RESULTS

The percentage of BIS 40-60 was significantly higher in the AutoTIVA compared to DES, SEVO and ManualTIVA (87% vs. 78 %, 58%, 39%, respectively; P≤0.001). The percentage of BIS<40 was significantly lower in AutoTIVA than in the other groups (P<0.001). No difference in hemodynamics was found among groups. Postoperative MMSE scores were similar to baseline in the AutoTIVA (26 [24-28] vs. 26 [23-28]) while they markedly decreased in all other groups (P<0.001). Postoperative MMSE decreased at any age. None experienced awareness was recorded.

CONCLUSIONS

Our results suggest that patients treated with AutoTIVA performed better in the cognitive test compared to the other groups receiving manual target-controlled GA due to a higher adequate level of anesthesia measured by BIS. Cognitive tests should be performed to test ED in all patients undergoing GA.