Ketamine With Multilevel Paravertebral Block for Post Video-assisted Thoracic Surgery Pain

Study Overview
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Brief Summary
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Postoperative pain after thoracic surgery is associated with adverse outcomes. The current strategy to prevent postoperative pain is the use of regional anesthesia and analgesic agents. In video-assisted thoracic surgery (VATS), thoracic paravertebral block has become the standard analgesic regimen which results in decreased postoperative pain and opioid consumption. The investigator would like to study the analgesic efficacy of low dose intravenous ketamine infusion during surgery in combination with thoracic paravertebral block on postoperative pain after VATS in a randomized study.

Detailed Description
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Inadequate pain control after thoracic surgery is associated with adverse events such as postoperative pulmonary complications (PPC), and chronic post surgical pain. Although the less invasive video-assisted thoracic surgery (VATS) has been used extensively as it produces optimal surgical outcomes and possible less postoperative pain, there are reports of inadequate pain control. Thoracic paravertebral block (TPVB) has been introduced as an effective method in postoperative pain management after VATS. It is associated with improved pain control and the reduction of opioid analgesic consumption in several studies. The use of intravenous low dose ketamine infusion during and after surgery has been shown to produce superior postoperative pain control in upper abdominal surgery and thoracotomy. The aim of the present study is to study the efficacy of intravenous low dose ketamine infusion during surgery on acute and chronic pain after VATS.

Official Title
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Low Dose Intraoperative Intravenous Ketamine in Combination With Multilevel Paravertebral Block for Post Video-assisted Thoracic Surgery Pain: a Randomized Study

Conditions
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Pain, Acute, Pain, Chronic, Pain, Neuropathic

Intervention / Treatment
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* Drug: Ketamine
* Drug: Normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologist physical status 1-3 Scheduled for elective video-assisted thoracic surgery Able to operate a patient-controlled analgesia device (PCA) Exclusion Criteria: History of morphine allergy History of bupivacaine allergy Contraindication for ketamine infusion Contraindication for thoracic paravertebral block Anticipated postoperative positive pressure ventilation Body mass index more than 35 Any known psychiatric disorder

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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 |
| --- | --- |
| Experimental: Ketamine<br>Participant allocated to this arm will receive intravenous ketamine infusion starting after the induction of anesthesia until the end of the surgery at the beginning of skin closure Participant will receive an ultrasound-guide thoracic paravertebral block using 0.5% plain bupivacaine prior to the induction of anesthesia | Drug: Ketamine<br>* intravenous ketamine 0.2 mg/kg/hr (concentration 1 mg/ml)<br>|
| Placebo Comparator: Normal saline<br>Participant allocated to this arm will receive intravenous normal saline solution infusion starting after the induction of anesthesia until the end of the surgery at the beginning of skin closure Participant will receive an ultrasound-guide thoracic paravertebral block using 0.5% plain bupivacaine prior to the induction of anesthesia | Drug: Normal saline<br>* normal saline infusion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative morphine consumption | Amount of morphine (in milligrams) which is dispensed from a patient-controlled analgesia device (PCA) | 24 hours postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to first analgesia | Time period (in minutes) after the end of surgery until the time of first morphine solution is dispensed from PCA device | 24 hours postoperatively | 
| Peak flow rates (day 1) | The value of peak flow velocity obtained from the first postoperative day will be compare with the value at the preoperative period | 1 days | 
| Peak flow rates (day 2) | The value of peak flow velocity obtained from the first postoperative day will be compare with the value at the preoperative period | 2 days | 
| Chronic post-surgical pain | The score of the Thai version of PainDetect questionnaire will be obtained at 1 month postoperatively | 1 month | 
| Chronic post-surgical pain | The score of the Thai version of PainDetect questionnaire will be obtained at 3 months postoperatively | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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anesthesia, thoracic surgery, thoracic paravertebral block, ketamine