Peri-neural Dexmedetomidine as an Adjuvant to Bupivacaine Induced Paravertebral Block in Patients Undergonig Thoracotomy

Study Overview
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Brief Summary
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This study evaluates the effect of adding dexmedetomidine as an adjuvant to bupivacaine in patients undergoing thoracotomy when administered peri-neurally in thoracic paravertebral space.

Detailed Description
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Thoracotomy is associated with severe postoperative pain that could be reduced with an aggressive analgesic therapy in the early postoperative period. The use of thoracic paravertebral block is an effective analgesic approach for post-thoracotomy pain. Several local anesthetic adjuvants have been reported to extend the duration of paravertebral block. Alpha-2 agonists including dexmedetomidine appear to be the most effective in this context. The study will include an intervention group which will receive a combination of 20 ml bupivacaine 0.5% and dexmedetomidine 0.5 ml (50 microgram). The control group will receive 20 ml bupivacaine 0.5% plus 0.5 ml normal saline perineurally. Thoracic paravertebral catheter will be inserted preoperatively. Visual analogue pain score will be assessed at different intervals.

Official Title
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Peri-neural Dexmedetomidine as an Adjuvant to Bupivacaine-induced Paravertebral Block in Patients Undergoing Thoracotomy

Conditions
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Acute Post-thoracotomy Pain

Intervention / Treatment
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* Drug: dexmedetomidine bupivacaine
* Drug: Bupivacaine saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American society of anesthesiologists physical status class ||or |||. Patients scheduled for elective thoracotomy. Exclusion Criteria: Pneumonectomy, decortication, pleural biopsy. Additional chest wall resection. Emergency surgery. Central and peripheral neuropathies.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: bupivacaine saline group<br>This group of patients will receive 20 ml bupivacaine plus 0.5 ml normal saline perineurally in the paravertebral catheter | Drug: Bupivacaine saline<br>* perineural bupivacaine saline mixture in the thoracic paravertebral catheter<br>|
| Active Comparator: Dexmedetomidine- bupivacaine group<br>This group of patients will receive 20 ml bupivacaine plus 0.5 ml (50 microgram) dexmedetomidine administered perineurally in the paravertebral catheter. | Drug: dexmedetomidine bupivacaine<br>* perineural dexmedetomidine as an adjuvant to bupivacaine induced thoracic paravertebral block<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of first loading preoperative dose of paravertebral injectate | Time interval between initiation of the paravertebral block and the time to first rescue analgesia | One day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of surgery and anesthesia | Times from start of anesthesia and surgery to the conclusion of surgical intervention | Intraoperative period, up to 3-4 hours | 
| End tidal isoflurane | Average End-tidal isoflurane concentration required to maintain stable hemodynamics | Duration of anesthesia, up to 3-4 hours | 
| Total intraoperative fentanyl requirements | The total dose of fentanyl required during the surgical procedure to maintain hemodynamic stability | Intraoperative period, up to 3-4 hours | 
| Total intraoperative ephedrine and atropine requirements | The total amounts of ephidrine and atropine required for the treatment of possible reduction of arterial blood pressure or heart rate | Intraoperative period, up to 3-4 hours | 
| Total intraoperative crystalloid requirements | The total volume of intraoperative fluids in ml required to maintain hemodynamic stability | Intraoperative period, up to 3-4 hours | 
| Recovery time | the time interval between discontinuation of isoflurane and the patient first response to verbal commands | Immediate postoperative period, up to 2 hour | 
| Pain intensities at rest and during coughing as assessed by 0-10 VAS score | Pain scores will be assessed using the 11-points visual analogue pain score (VAS) where 0 indicates no pain and 10 indicates the worst pain. | Over 48 hours postoperatively | 
| Total doses of bupivacaine, dexmedetomidine, and morphine | The total doses of three medications will be recorded and compared in the intervention and control groups | 48 hours postoperatively | 
| Number of paravertebral to-up injections | The number of to-up doses of bupivacaine required to maintain adequate postoperative analgesia over 48 hours postoperatively | 48 hours postoperatively | 
| Side effects | Patients will be monitored for the possible reductions in arterial blood pressure and heart rate | 48 hours postoperatively |