Spinal Anesthesia
Conditions
Keywords
Age, Pharmacodynamics, dexmedetomidine
Brief summary
Dexmedetomidine(DEX) is a novel , highly selective α2 adrenergic receptor agonists , and its selectivity for α2 receptor is 1600 times higher than α1.It also could provide dose-dependent sedation , analgesia , anti-anxiety and inhibition of sympathetic nerves and other effects .At earlier time It was approved by the FDA only for short-time sedation during mechanical ventilation of adult patients (\<24h) in ICU. 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 gender,such as the drug sensitivity of propofol and remifentanil is increased with age,while the current study also demonstrated that gender may influence the sedate efficacy of propofol and the sensitivity of muscle loose of rocuronium. Current studies with regard to the effects of age and gender on dexmedetomidine pharmacodynamic are rare. The study is aim to explore the right DEX dose of different 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 BIS,during the operation.The relation between BIS values and the depth of sedation for patients is also investigated.
Detailed description
120 patients scheduled to undergo lower extremity surgery were included in one of three groups. Determination of median effective (ED50) doses was performed by the Dixon and Mood up-and-down method. Initial doses was 1μg/kg, with dose adjustment intervals of 0.05μg/kg, in the youth,and middle-aged group. The initial doses of DEX was 0.7 μg/kg,also with dose adjustment intervals of 0.05μg/kg.Sedative efficacy was defined as an OAA/S of ≤2, or an OAA/S of 3 but with an BIS value of ≤46, 26 min after the beginning of drug administration.
Interventions
Initial doses was 1μg/kg, with dose adjustment intervals of 0.05μg/kg.
DRUGDexmedetomidine 02
Initial doses was 0.7μg/kg, with dose adjustment intervals of 0.05μg/kg.
Sponsors
Guangzhou General Hospital of Guangzhou Military Command
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. ASA Ⅰ \ Ⅱ patient undergoing lower extremity surgery 2. Written informed consent from the patient or the relatives of the participating patient. 3. BMI:18.5～25
Exclusion criteria
1. Mental illness can not match 2. epidural anesthesia contraindicated 3. People who have Slow-type arrhythmias 4. People who were language or hearing impaired 5. Sensory block reached to T8 or higher. 6. People who had lung infection or sleep apnea syndrome. 7. Pregnancy 8. Chronic renal failure 9. Alcohol or drug abuse 10. Already taking gabapentin, pregabalin, benzodiazepin or antidepression drug
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The ED50 of DEX | 26min after the start of the infusion | The aim of our study is to define the median effective sedative doses (ED50s) of DEX to determine the effect of age on the pharmacodynamic of DEX in lower extremity surgery using the Dixon and Mood up-and-down method。 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The ED95 of DEX | 26min after the start of the infusion | To determine the optimum bolus dose (ED95) of dexmedetomidine for producing adequate sedation during spinal anesthesia in lower limb orthopedic surgery. |
Countries
China
Outcome results
None listed