The Application of Target Controlled Infusion of Etomidate Combined With Propofol in the Maintenance of Anesthesia During Brain Surgeries

Study Overview
=================
Brief Summary
-----------------
To explore the application of target controlled infusion of etomidate combined with propofol in the maintenance of anesthesia during brain surgeries.

Conditions
-----------------
Target Controlled Infusion, General Anesthesia

Intervention / Treatment
-----------------
* Drug: propofol
* Drug: etomidate


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Aged between 60 and 80 years Brain surgeries Body weight is between 45 to 75 kg and body mass index is no more than 30 kg/m2 American Society of Anesthesiology (ASA) Physical Status: Ⅰ or Ⅱ Expected operation duration is between 3 and 5 h Signed informed consent form Exclusion Criteria: Serious cardiac, cerebral(acute stroke, uncontrolled seizure, sever dementia), liver, kidney, lung, endocrine disease or sepsis History of general anesthesia within 24 h before the operation Long use of hormone or history of adrenal suppression Hyperlipidaemia Long use of psychotropic substances Systolic pressure is still under 90 mm Hg after twice given of vasopressor agent Suspected abuse of narcotic analgesia Patients need to use neuromuscular blocking drugs (except intubation) Allergy to trial drug or other contraindication Pregnant or breast-feeding women Attendance of other trial past 30 days

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 60 Years

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

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

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

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group A<br>During maintenance of anesthesia, etomidate was give by target controlled infusion, the effect-site concentration is 0.3 to 0.6 micrograms/ml to keep bispectral index between 40 to 60. | Drug: etomidate<br> <br> * Other names: Fu Er Li;|
| Experimental: Group B<br>During maintenance of anesthesia, Propofol was give by target controlled infusion, the effect-site concentration is 2 to 4 micrograms/ml to keep bispectral index between 40 to 60. | Drug: propofol<br> <br> |
| Experimental: Group C<br>During maintenance of anesthesia, etomidate will be given by target controlled infusion for 2 h first, and then propofol will be given by target controlled infusion, the effect-site concentration is 0.3 to 0.6 micrograms/ml and 2 to 4 micrograms/ml, respectively. Bispectral index should be kept between 40 to 60. | Drug: propofol<br> <br> Drug: etomidate<br> <br> * Other names: Fu Er Li;|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | Heart rate should be recorded before induction, 1 min, 5 min, 20 min after intubation, at the time of skin incision, skull drilling, incision of dura matter, during intracranial operation, suture of dura matter and skin. | Baseline to the end of the operation, expected to be about 6 h | 
| Blood pressure | Blood pressure should be recorded before induction, 1 min, 5 min, 20 min after intubation, at the time of skin incision, skull drilling, incision of dura matter, during intracranial operation, suture of dura matter and skin. | Baseline to the end of the operation, expected to be about 6 h | 
| Concentration of cortisol | Concentration of cortisol should be recorded before induction, 30 min, 1 h, 2 h after intubation, and immediately when the operation is over. | from baseline to the end of the operation, expected to be about 6 h | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Use of vasoactive agent | The name and dose of the vasoactive agents used from the beginning of induction to the end of operation. | from the beginning of induction to the end of the operation, expected to be about 6 h | 
| The time from stop of remifentanil to awake |  | The time from stop of remifentanil to awake, expected to no more than 15 min | 
| Severity of agitation |  | Within 24 h after the operation | 
| Postoperative nausea and vomiting |  | Within 24 h after the operation | 
| Dose of etomidate and propofol |  | From the beginning of induction to the end of the operation, expected to be about 6 h | 
| Intraoperative awareness |  | From the beginning of induction to the end of the operation, expected to be about 6 h | 
| Expense of anesthetics |  | From the beginning of induction to the end of the operation, expected to be about 6 h | 
| Allergic reaction |  | From beginning of induction to 24 h after the operation |