Effect of Epidural Analgesia on Burst Suppression

It has been shown in previous studies that burst suppression has an effect on the development of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD). With the development of technology, EEG-based anesthesia management is getting more and more attention. In particular, methods that reduce anesthetic drug consumption are expected to prevent POD and POCD by reducing burst suppression. There are studies that show that epidural analgesia applications reduce general anesthesia drug consumption in patients receiving general anesthesia. In this study, investigators want to investigate the effect of epidural analgesia combined with general anesthesia on burst suppression. POD and POCD development in these patients will be examined as secondary objectives.

Inclusion Criteria:American Society of Anesthesiologists (ASA) Physical Status 1-3Hip or knee arthroplasty surgeryExclusion Criteria:severe renal failure (need for renal replacement therapy)severe liver failure (child-pudg grade c)body mass index >40long-term use of some drugs (sedatives, tricyclic antidepressants, narcotic painkillers)having a disease related to the nervous systemhaving a psychiatric diseasehaving a history of substance abusehaving consumed 2 or more glasses of alcohol per day in the last 1 yearcontraindications for neuraxial blockallergy to drugs to be usedemergency surgeriespatient's refusal to accept the procedurehearing and visual impairmentanesthesia awareness historypreoperative delirium