The ED50 of DEX for Providing Sedation in Different Female Age Group

Study Overview
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Brief Summary
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Dexmedetomidine(DEX) could provide dose-dependent sedation , analgesia , anti-anxiety and inhibition of sympathetic nerves and other effects. Because of its minimal impact on the respiratory , currently it was more and more widely used to sedate patients undergoing regional anesthesia.Many anesthetic pharmacokinetics and pharmacodynamics are often affected by age, and current studies with regard to the effects of age on dexmedetomidine pharmacodynamic are rare. This study was designed to explore the right DEX dose of different female Age of patients to produce suitable sedation.Dexmedetomidine be used in patients with combined spinal and epidural anesthesia for sedation,which is monitored by the Narcotrend,during the operation.The relation between Narcotrend index (NTI) and the depth of sedation for patients is also investigated.

Detailed Description
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90 patients scheduled for combined spinal epidural spinal anesthesia were included in one of three groups. In each group,determination of median effective (ED50) doses was performed by the Dixon up-and-down method, an initial dose of 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1 μg/kg in first three turning points and 0.05μg/kg in the last three turning points.Initial doses was 1.4μg/kg, .Sedative efficacy was defined as an OAA/S of ≤3,30 min after the beginning of drug administration.

Conditions
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Combined Spinal-epidural Anesthesia

Intervention / Treatment
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* Drug: Dexmedetomidine A
* Drug: Dexmedetomidine B
* Drug: Dexmedetomidine C


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA Ⅰ   Ⅱ patient undergoing lower extremity surgery Written informed consent from the patient or the relatives of the participating patient. BMI:18.0～25.0kg/m2 Exclusion Criteria: Mental illness can not match epidural anesthesia contraindicated People who have Slow-type arrhythmias People who were language or hearing impaired Sensory block reached to T8 or higher. People who had lung infection or sleep apnea syndrome. Pregnancy Chronic renal failure Alcohol or drug abuse Already taking gabapentin, pregabalin, benzodiazepin or antidepression drug - -

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 79 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Youth female group<br>patients in the Youth female group, aged 20 35, were accepted an initial dose of 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last three turning points. | Drug: Dexmedetomidine A<br>* initial dose was 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last three turning points.<br>* Other names: Dexmedetomidne in youth female group;|
| Experimental: Middle-aged female group<br>patients in the Middle-aged female group, aged 40 60, were accepted an initial dose of 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last three turning points. | Drug: Dexmedetomidine B<br>* initial dose was 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last three turning points.<br>* Other names: Dexmedetomiodine in middle-age female group;|
| Experimental: Elderly female group<br>Patient in the elderly female group, aged 65 79, were accepted an initial dose of 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last three turning points. | Drug: Dexmedetomidine C<br>* initial dose was 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last three turning points.<br>* Other names: Dexmedetomidine in elderly female group;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The ED50 of DEX for providing sedation | The aim of this study is to define the optimum bolus dose (ED50) of dexmedetomidine for producing adequate sedation during spinal anesthesia in different female age group using the Dixon and Mood up-and-down method。 | 30min after the start of the infusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The ED95 of DEX | To determine the optimum bolus dose (ED95) of dexmedetomidine for producing adequate sedation during spinal anesthesia in different female age group. | 30min after the start of the infusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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age, sedation, dexmedetomidine