The Application of Response Surface Model on Sedative Procedures

Study Overview
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Brief Summary
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The purpose of this study is to find the application of Response Surface Model on Sedative Procedures.

Detailed Description
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It is very important to understand the influence of drug interactions of patients in clinical anesthesia. However, there were only a few quantitative studies on the pharmacodynamics of different drug combinations and patient responses. In recent years, the investigators have innovatively utilized the response surface models in patients receiving painless gastro-intestinal endoscopies. Appropriate pharmacodynamic models of clinical anesthesia for these procedures provide observation, evaluation, and prediction of the pharmacodynamic effects of a combination of clinical anesthetics to such patients. Patients with endoscopic retrograde cholangiopancreatography (ERCP) and bronchoscopy often have a need for painless service, but current clinical studies of using a pharmacodynamic model were lacking in these patients. The investigators therefore design a two-year prospective, observational project to investigate the optimal drug concentration combinations for the shortest wake-up time, adequate analgesia, and appropriate depth of anesthesia for sedative endoscopic ERCP and sedative bronchoscopy using pharmacodynamic models. Multidimensional surface charting will be performed by inputting diversified parameters to predict the drug interactions of the model groups. In this prospective, observational study, the investigators plan to enroll 40 ASA Class Forty ASA Class II-III, aged 20-80 adult patients who require sedative ERCP and bronchoscopy. Moderate to heavy sedation will be performed only after patients' inform consents and approval of the institutional ethics committee. The investigators plan to complete this series of studies within two years: The first year: ERCP(10 patients) and broncoscopy (10 patients). The second year: ERCP(10 patients) and broncoscopy (10 patients). Using response surface models, this study will offer us novel information about patients during procedures which may substantially increase the anesthesia quality and outcome of sedative ERCP and broncoscopy. Physiological signals such as anesthesia depth, drug concentrations and dosages, alertness/sedation score, heart rate, blood pressure, peripheral oxygen saturation, and physical activity responses during painless procedures will be collected and then the above data will be applied to the response surface models. Then the investigators will find the most appropriate anesthetic response surface which may delineate the effects of drug combinations, and will further improve the anesthesia safety and quality for painless ERCP and bronchoscopy patients.

Official Title
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The Application of Response Surface Model on Sedative Endoscopic Retrograde Cholangiopancreatography and Sedative Bronchoscopy

Conditions
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Anesthesia

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA Class II-III, Aged 20-80 adult patients Undergoing moderate sedation during ERCP (endoscopic retrograde cholangiopancreatography) and brochoscopy Exclusion Criteria: Neurological disorders Hearing impairment History of habitual sedative medication Alcoholism

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 |
| --- | --- |
| Brochoscopy<br>20 ASA Class II-III, aged 20-80 adult patients who require moderate sedation during bronchoscopy will be enrolled into this study. The moderate sedation will be performed only after patients' inform consents and approval of the institutional ethics committee. Patients with conditions such as neurological disorders, hearing impairment, history of habitual sedative medication and alcoholism will be excluded from this study. | |
| ERCP<br>20 ASA Class II-III, aged 20-80 adult patients who require moderate sedation during ERCP will be enrolled into this study. The moderate sedation will be performed only after patients' inform consents and approval of the institutional ethics committee. Patients with conditions such as neurological disorders, hearing impairment, history of habitual sedative medication and alcoholism will be excluded from this study. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Response Surface Models | Pharmacodynamic response surface model is a mathematic model which provides information about when and what extent the patient will response to a specific physiological condition (pain, respiratory depression, anesthesia depth….) in a given combination drug concentration pairs. The calculated plasma or effect concentration of specific medications will be used to train iteratively by non-linear regression to find the optimal parameters to construct a new response surface model. Then the model will be validated by the observation data to see the accuracy and efficacy of the model. | 10 seconds from once the anesthetics were terminated to 10 minutes after the time of each patient's wake up | 
| Evaluation of Response Surface Model Predictions | Model predictions were evaluated at the emergence period of moderate sedation or general anesthesia. Model predictions of OAA/S ranging from 0% to 100% were made every 10 seconds from once the anesthetics were terminated to 10 minutes after the time of each patient's wake up. Model predictions were compared with observations with graphical and temporal analyses | 10 seconds from once the anesthetics were terminated to 10 minutes after the time of each patient's wake up |