Effect of Sedatives on Perioperative Electroencephalogram in Elderly Patients Undergoing Spinal Anesthesia

Study Overview
=================
Brief Summary
-----------------
In the present study, we observe perioperative findings of electroencephalogram in sedated and non-sedated elderly patients undergoing total knee arthroplasty under spinal anesthesia.

Detailed Description
-----------------
In the present study, we observe perioperative findings of electroencephalogram in sedated and non-sedated elderly patients undergoing total knee arthroplasty under spinal anesthesia. Electroencephalogram is performed before, during, and 1 day after surgery. After the induction of anesthesia, sedation is performed according to the patient's request. If a patient want to be sedated during surgery, one of the three sedatives (dexmedetomidine, propofol, and midazolam) is administered.

Official Title
-----------------
Effect of Sedatives on Perioperative Electroencephalogram in Elderly Patients Undergoing Spinal Anesthesia

Conditions
-----------------
Effect of Sedatives

Intervention / Treatment
-----------------
* Device: Electroencephalogram


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Eldery patients scheduled for spinal anesthesia Exclusion Criteria: MMSE ≤ 23 Hemodynamic unstability Liver disease Renal disease

Ages Eligible for Study
-----------------
Minimum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Control<br>Patients who do not want to be sedated during spinal anesthesia are included. Electroencephalogram is performed before, during, and 1 day after surgery. | Device: Electroencephalogram<br>* Electroencephalogram is performed before, during, and 1 day after surgery in elderly patients undergoing spinal anesthesia.<br>|
| Dexmedetomidine<br>Patients who want to be sedated during spinal anesthesia are included. Electroencephalogram is performed before, during, and 1 day after surgery. After the induction of spinal anestheisa, dexmedetomidine is administered for sedation during surgery. | Device: Electroencephalogram<br>* Electroencephalogram is performed before, during, and 1 day after surgery in elderly patients undergoing spinal anesthesia.<br>|
| Propofol<br>Patients who want to be sedated during spinal anesthesia are included. Electroencephalogram is performed before, during, and 1 day after surgery. After the induction of spinal anestheisa, propofol is administered for sedation during surgery. | Device: Electroencephalogram<br>* Electroencephalogram is performed before, during, and 1 day after surgery in elderly patients undergoing spinal anesthesia.<br>|
| Midazolam<br>Patients who want to be sedated during spinal anesthesia are included. Electroencephalogram is performed before, during, and 1 day after surgery. After the induction of spinal anestheisa, midazolam is administered for sedation during surgery. | Device: Electroencephalogram<br>* Electroencephalogram is performed before, during, and 1 day after surgery in elderly patients undergoing spinal anesthesia.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| EEG frequency bands (alpha, beta, theta, delta, and gamma waves) during spinal anesthesia | EEG frequency bands are observed during spinal anesthesia under sedated or unsedated states. | 30 min after the induction of spinal anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| EEG frequency bands (alpha, beta, theta, delta, and gamma waves) 1 day after surgery | EEG frequency bands are observed after surgery and compared with the preoperative findings. | 1 day after surgery | 
| Incidence of delirium | Delirium is assessed after surgery. | For 7 days after surgery. |