The Influence of Age on Dexmedetomidine Pharmacodynamic

Guangzhou General Hospital of Guangzhou Military Command

Status and phase: Completed; Phase 4

Conditions: Spinal Anesthesia

Treatments: Drug: Dexmedetomidine 02; Drug: Dexmedetomidine 01

Study type: Interventional

Funder types: Other

Identifiers

NCT02099253

DEX Pharmacodynamics

Details and patient eligibility

About

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.

Full 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.

Enrollment: 82 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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82 participants in 3 patient groups

Youth Group

Experimental group

Description:

People in this group, aged 18\~39,were accepted an initial dose of 1μg/kg, with dose adjustment intervals of 0.05μg/kg.

Treatment:

Drug: Dexmedetomidine 01

Middle-aged Group

Experimental group

Description:

People in this group, aged 40\~64,were accepted an initial dose of 1μg/kg, with dose adjustment intervals of 0.05μg/kg.

Treatment:

Drug: Dexmedetomidine 01

Older Group

Experimental group

Description:

People in this group, aged 65\~80,were accepted an initial dose of 0.7μg/kg, with dose adjustment intervals of 0.05μg/kg.

Treatment:

Drug: Dexmedetomidine 02