Effects of Dexmedetomidine on Stress Response and Postoperative Analgesia

Study Overview
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Brief Summary
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Dexmedetomidine is a highly selective α2 adrenoreceptor agonist approved by the US FDA for short-term postoperative sedation and analgesia.It can also reduce the stress response without respiratory depression. In this prospective, randomized, double-blind, placebo-controlled study，we gave dexmedetomidine or saline placebo 1h before operations were over and assessed the effects of dexmedetomidine on stress response and postoperative analgesia in patients undergoing thoracotomy during anesthesia recovery period.

Detailed Description
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Dexmedetomidine can significantly reduce the emergence agitation and postoperative pain in patients who received chest surgery

Official Title
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Effects of Dexmedetomidine on Stress Response and Postoperative Analgesia in Patients Undergoing Thoracotomy During Anesthesia Recovery Period

Conditions
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Restlessness, Pain

Intervention / Treatment
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* Drug: dexmedetomidine
* Drug: saline placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anaesthesiologists Physical Status (ASA-PS) I or II undergoing selective thoracotomy weight between 45 and 75kg operation time 2-4 hours Exclusion Criteria: history of neurologic disease history of chronic analgesics intake history of allergic reactions to the experimental durgs history of renal insufficiency history of hepatic dysfunction history of coagulation disorders women in lactation participating in other studies

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group-DEX<br>Patients in this arm received dexmedetomidine 0.2 microgram per kg i.v. during 10 minutes 1 hour before the end of surgery | Drug: dexmedetomidine<br>* In this arm,midazolam(0.03-0.05mg/kg), propofol(1.5-2.5mg/kg),sufentanil(0.6-0.82μg/kg )and rocuronium(0.8-1.0mg/kg) were used in anesthesia induction. Anaesthesia was maintained with propofol（4-6mg kg-1h-1），remifentanil (0.1-0.2 μg kg-1 min-1）and sevoflurane（1%).Propofol was titrated to maintain intraoperative Narcotrend values between 20 and 46. Patients in this arm received dexmedetomidine 0.2μg/kg i.v. during 10 minutes 1 hour before the end of surgery<br>|
| Placebo Comparator: Group-PLB<br>Patients in this arm received saline placebo 0.05 ml per kilogram i.v. during 10 minutes 1 hour before the end of surgery | Drug: saline placebo<br>* In this arm,midazolam(0.03-0.05mg/kg), propofol(1.5-2.5mg/kg),sufentanil(0.6-0.82μg/kg )and rocuronium(0.8-1.0mg/kg) were used in anesthesia induction. Anaesthesia was maintained with propofol（4-6mg kg-1h-1），remifentanil (0.1-0.2 μg kg-1 min-1）and sevoflurane（1%).Propofol was titrated to maintain intraoperative Narcotrend values between 20 and 46. Patients in this arm received saline placebo of the same volume i.v. during 10 minutes 1 hour before the end of surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Emergence agitation | Emergence agitation was assessed by the highest restlessness score（RS）during 0-3 postoperative hours | during 0-3 postoperative hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain at rest | The patients were instructed to give the number that represented the pain level at rest by using visual analogue scale（VAS）and prince-henry score | At 1,3 postoperative hours | 
| dosage Dosage of analgesics |  | during 3 postoperative hours | 
| Recovery time |  | At the moment of the eyes opend when calling the names | 
| Postoperative sedation | It was assessed by Ramsay Sedation Score(RSS) | at 0,1,3 postoperative hours | 
| Extubation time |  | at the moment of extubation | 
| Breathing recovery time |  | when autonomous respiration recovered |