Predicting Bispectral Index Values by Estimated Effect-site Concentration of Propofol and Remifentanil Displayed on the Target-centered Infusion Pump

Study Overview
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Brief Summary
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The BIS is influenced by multiple parameters, such as age,gender, body weight, height, muscle relaxants, hepatic function, co-administered drugs, surgical stimulation, but is thought to be influenced mainly by propofol and remifentanil infusion dose. As such, the investigators postulate that the BIS value could be predicted by the estimated effects-site concentration of propofol and remifentanil, and try to establish a multiple linear regression model for predicting BIS value.

Detailed Description
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Total intravenous anesthesia is commonly performed with propofol and remifentanil now-a-days. The combination of these two drugs can achieve the rapid loss of consciousness and analgesia,as the onset and recovery time of these two drugs are very fast within one to three minutes. However, the problem of intraoperative awareness necessitate the monitoring of anesthetic depth, which is commonly performed with Bispectral index (BIS). BIS is a display of number from zero to one hundred which quantify the degree of sedation and hypnosis by anesthetics by analyzing the electroencephalogram. However, it is limited in neurosurgery in which the surgical field is near the forehead where the BIS probe is attached. Furthermore, it is also limited in surgery with prone position. The BIS is influenced by multiple parameters, such as age,gender, body weight, height, muscle relaxants, hepatic function, co-administered drugs, surgical stimulation, but is thought to be influenced mainly by propofol and remifentanil infusion dose. As such, we postulate that the BIS value could be predicted by the estimated effects-site concentration of propofol and remifentanil, and try to establish a multiple linear regression model for predicting BIS value.

Official Title
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Predicting Bispectral Index Values by Estimated Effect-site Concentration of Propofol and Remifentanil Displayed on the Target-centered Infusion Pump

Conditions
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General Anesthesia, Total Intravenous Anesthesia, Bispectral Index Monitoring

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Those undergoing gynecologic or urologic surgery with general anesthesia with total intravenous anesthesia Adult patients with more than 20 yrs. American Society of Anesthesiologists Class I or II. Exclusion Criteria: Those with unstable hemodynamics Those who can not undergo Bispectral index monitoring Those with previous history of stroke

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Gynecologic surgery group<br>Those undergoing gynecologic laparoscopic surgery with TIVA | |
| Urologic surgery group<br>Those undergoing urologic surgery with TIVA | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Bispectral index value | Bispectral index value after anesthetic induction every 10 minutes interval until the end of surgery | every 10 min after anesthetic induction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Propofol concentration | estimated propofol effect-site concentration displayed in target-centered infusion pump every 10 minutes interval | every 10 min after anesthetic inducton | 
| Remifentanil concentration | estimated remifentanil effect-site concentration displayed in target-centered infusion pump every 10 minutes interval | every 10 minutes after anesthetic induction | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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total intravenous anesthesia, Bispectral index monitoring, propofol, remifentanil