Comparison of the Effect of Intravenous and Perineural Dexmedetomidine in Gastric Cancer Surgery

Study Overview
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Brief Summary
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Using random case assignment to investigate the analgesic and sedative effect of intravenous dexmedetomidine and dexmedetomidine as a local anesthetic adjuvant in ultrasound-guided subcostal TAP block in gastric cancer patient undergoing gastrectomy or partial gastrectomy.

Detailed Description
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The process of the experiment (brief describe) The participant patients will be randomly allocated into three groups: the intravenous dexmedetomidine group (Dex_iv group), dexmedetomidine adding to local anesthetic as an adjuvant for subcostal TAP block (Dex_adj group), and Control group. All patients receive gastrectomy or partial gastrectomy in general anesthesia as standard. Thirty minutes before the end of surgery, the patients in Dex_iv group receive 0.5mcg/kg dexmedetomidine infusion for 30 minutes, while the patients in Dex_adj group and control group receive 0.125ml/kg 0.9% normal saline IV infusion for 30 minutes. All patients have ultrasound-guided TAP block single injection after the end of surgery and before the tracheal tube extubation. The block agents in Dex_adj group is 40 ml of 0.375% ropivacaine with 0.5mcg/kg dexmedetomidine, while in Dex_iv group and control group are only 40ml of 0.375% ropivacaine. The IV PCA pump will be set up before patients awaken in the post-anesthesia care unit. All patients are assessed for the signs of emergence agitation with Riker sedation-agitation scale in the post-anesthesia care unit. The numerical rating scale (NRS) for pain intensity assessment, the opioid consumption via IV PCA pump, and the patients satisfaction will be documented for postoperative 3 days for the impact evaluation of dexmedetomidine in postoperative analgesia in patients undergoing gastric cancer surgery with subcostal TAP block.

Official Title
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Comparison of the Effect of Intravenous Continuous Dexmedetomidine Infusion and Dexmedetomidine as a Local Anesthetic Adjuvant in Subcostal Transverse Abdominis Plane Block in Patients Undergoing Gastric Cancer Surgery

Conditions
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Gastric Cancer, Pain, Postoperative

Intervention / Treatment
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* Drug: Dexmedetomidine
* Drug: 0.9% Sodium-chloride


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: gastric cancer patients undergoing gastrectomy or partial gastrectomy, who receive ultrasound-guided subcostal TAP block and PCA for postoperative analgesia Exclusion Criteria: surgery involved other visceral organ (eg. combined splenectomy or partial hepatectomy), patients with histories of adverse drug reaction to dexmedetomidine, bradycardia (baseline heart rate <60 beats/min), any type of atrioventricular block in electrocardiogram (EKG), heart failure, significant renal or hepatic impairment, severe bronchopulmonary disease, any coagulant disorder, and pregnant or breast-feeding woman.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 75 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexmedetomidine_iv group<br>Dexmedetomidine 0.5mcg/kg (diluted in normal saline) intravenously infusion for 30min | Drug: Dexmedetomidine<br>* 0.5mcg/kg intravenous(IV)continuous infusion for 30 minutes, or 0.5mcg/kg adding to local anesthetic for subcostal TAP block<br>* Other names: Precedex;|
| Experimental: Dexmedetomidine_adj group<br>Dexmedetomidine 0.5mcg/kg (adding to local anesthetic) perineural single bolus for subcostal TAP block 0.9% sodium chloride 0.125ml/kg intravenously infusion for 30min | Drug: Dexmedetomidine<br>* 0.5mcg/kg intravenous(IV)continuous infusion for 30 minutes, or 0.5mcg/kg adding to local anesthetic for subcostal TAP block<br>* Other names: Precedex;Drug: 0.9% Sodium-chloride<br>* 0.125ml/kg intravenously infusion in Dexmedetomidine_adj group and control group<br>|
| Active Comparator: Control group<br>0.9% sodium chloride 0.125ml/kg intravenously infusion for 30min No dexmedetomidine use | Drug: 0.9% Sodium-chloride<br>* 0.125ml/kg intravenously infusion in Dexmedetomidine_adj group and control group<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| analgesic effect - pain intensity | postoperative acute pain intensity (numerical rating scale, NRS, 0-10) | postoperative 3 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sedative effect | emergence agitation in post-anesthesia care unit (Riker sedation-agitation scale, 1-7) | postoperative 2 hours | 
| analgesic effect - opioid consumption | Fentanyl consumption(mcg) via patient-control analgesia (PCA) pump | postoperative 3 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Subcostal transversus abdominis plane block