PANDORA: Paravertebral AdjuNctive DexamethasOne Palmitate Reducing Chronic Pain After Caridiac Surgery

Study Overview
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Brief Summary
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The goal of this single-center, prospective, double-blind randomized controlled clinical trial is to explore preventive interventions for chronic postoperative pain (CPSP) in patients undergoing minimally invasive cardiac surgery. The main questions it aims to answer is: the incidence of CPSP is high and severe, and there is no safe and effective method for prevention and treatment. The participants in the dexamethasone palmitate (DXP) group will receive a single paravertebral space infusion of 21 ml of the first dose of analgesia, consisting of 0.5 percentage ropivacaine 20 ml and dexamethasone palmitate 1ml. The participants in dexamethasone sodium phosphate (DXM) group will receive a single infusion of a paravertebral space first dose of 21 ml of analgesic containing 0.5 percentage ropivacaine 20 ml and dexamethasone sodium phosphate 1ml. Then both groups use a continuous paravertebral nerve block pump for postoperative analgesia. The liquid of the pump is 250 ml 0.2 percentage ropivacaine. The background of the pump is set to 5 ml/h and PCA is set to 5 ml at an interval of 30 min.

Detailed Description
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Minimally invasive cardiac surgery has the advantages of small injury, rapid recovery and international leadership. But the incidence of chronic pain after operation is high, which is reported to be as high as 70 percentage in thoracic intercostal surgery, seriously affecting the quality of life of patients after surgery. Uncontrolled acute pain after surgery poses the greatest risk factor for CPSP. Procedure-specific postoperative pain management (PROSPECT) guidelines recommend that the use of paravertebral nerve block as the first choice for multimodal analgesia in intercostal surgery can significantly reduce the incidence of postoperative acute pain. But there is not enough evidence to prove that it can reduce the incidence of CPSP. Choosing a reasonable combination of analgesics in nerve block to inhibit the production and transmission of multi-source nociceptive signals caused by intercostal nerve injury and inflammatory stimulation is one of the research hotspots to prevent the transformation from acute pain to chronic pain. Dexamethasone can play an anti-inflammatory effect by reducing the sensitivity caused by neuroinflammation, which has also been confirmed by small sample studies. But a large number of literatures point out that a single use of dexamethasone cannot significantly reduce the incidence of CPSP. This may be due to the fact that the half-life of dexamethasone is only 48 hours, and single use is not enough to exert anti-inflammatory effects; long-term large-scale use can increase blood sugar concentration, leading to complications such as poor wound healing. From this, the investigators infer that finding a means or preparation to prolong the action time and efficacy of dexamethasone while reducing side effects may become an important means of preventing CPSP. Dexamethasone palmitate is a kind of dexamethasone nanoparticles with long curative effect, good effect and few side effects. It plays a very significant therapeutic role in the late stage of inflammation and has been proved to prevent the progression of inflammation. And there have been studies on the injection of dexamethasone palmitate in epidural or perineural space, but the safety and efficacy of dexamethasone palmitate in paravertebral space need to be further studied. The primary aim of this study is to compare whether single injection of dexamethasone palmitate and dexamethasone sodium phosphate around the paravertebral nerve combined with continuous paravertebral nerve block for postoperative analgesia can reduce the incidence of chronic pain 3 months after operation.

Official Title
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Effect of Continuous Paravertebral Nerve Block Combined With Dexamethasone Palpitate vs Combined With Dexamethasone Sodium Phosphate on Chronic Postoperative Pain in Patients Undergoing Minimally Invasive Cardiac Surgery

Conditions
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Chronic Postoperative Pain

Intervention / Treatment
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* Drug: Dexamethasone Palmitate
* Drug: Dexamethasone Sodium Phosphate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: NYHA class I-III 18 years to 65 years Undergoing intercostal incision cardiac surgery Exclusion Criteria: Urgent surgery BMI≧35kg/m^2 Non-first cardiac surgery Local anesthetic allergy Skin damage or infection at the puncture site Dysfunction of liver, kidney and blood coagulation

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: Sequential Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: DXP group<br>The participants in DXP group will receive a first dose of a single paravertebral space infusion of 21 ml of analgesic containing 0.5 percentage ropivacaine 20 ml and dexamethasone palmitate 1ml. | Drug: Dexamethasone Palmitate<br>* a single paraverteal space infusion of 21 ml of the first dose of analgesia, consisting of 0.5 percentage ropivacaine 20 ml and dexamethasone palmitate 1ml. Then, a continuous paraverteal nerve block pump was connected for postoperative analgesia. The liquid of the pump was 250 ml 0.2 percentage ropivacaine. The background of the pump was set to 5 ml/h and PCA was set to 5 ml at an interval of 30 min.<br>|
| Active Comparator: DXM group<br>The participants in DXM group will receive a single infusion of a paravertebral space first dose of 21 ml of analgesic containing 0.5 percentage ropivacaine 20 ml and dexamethasone sodium phosphate 1ml. | Drug: Dexamethasone Sodium Phosphate<br>* a single paraverteal space infusion of 21 ml of the first dose of analgesia, consisting of 0.5 percentage ropivacaine 20 ml and dexamethasone sodium phosphate 1ml. Then, a continuous paraverteal nerve block pump was connected for postoperative analgesia. The liquid of the pump was 250 ml 0.2 percentage ropivacaine. The background of the pump was set to 5 ml/h and PCA was set to 5 ml at an interval of 30 min.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of chronic postoperative pain | Pain status score on the Brief Pain Inventory（BPI-NRS score range, 0-10; ≥1 indicates it happens） | 3 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Morphine consumption | Total consumption of rescue analgesia by oral morphine equivalent (mcg/kg) | 24, 48, 72 hours after surgery | 
| The incidence of acute pain at resting and activity | Numerical Rating Scale to evaluate the incidence of pain (NRS score range, 0-10; ≥1 indicates it happens once) | 24, 48, 72 hours after surgery | 
| The incidence of chronic postoperative pain | Pain status score on the Brief Pain Inventory（BPI-NRS score range, 0-10; ≥1 indicates it happens） | 6 and 12 months after surgery | 
| Pain severity in the past 7 days | Patient-Reported Outcomes Measurement Information System (PROMIS) Scale v2.0 - Pain Intensity 3a (T-score range, 36.3-81.8; 81.8 indicates worst pain intensity) | 3, 6, 12 months after surgery | 
| Pain severity in the past 24 hours | Brief Pain Inventory (BPI pain intensity score rang, 0-40; 40 indicates worst pain intensity) | 3, 6, 12 months after surgery | 
| The interference of chronic postoperative pain on activities of daily living in the past 7 days | PROMIS Short Form v1.1 - Pain Interference 8a (PROMIS-PI-SF-8A; T-score range, 40.7-77; 77 indicates worst pain interference) | 3, 6, 12 months after surgery | 
| The interference of chronic postoperative pain on activities of daily living in the past 24 hours | Brief Pain Inventory (BPI pain interference score rang 0-70; 70 indicates worst pain interference) | 3, 6, 12 months after surgery | 
| The impact of chronic postoperative pain on neuropathic pain | PROMIS Scale v2.0 - Neuropathic Pain Quality 5a (T-score range, 37.0-74.1; 74.1 indicates highly neuropathic pain) | 3, 6, 12 months after surgery | 
| The impact of chronic postoperative pain on health related quality of life | 12-item Short-Form Health Survey v2 (SF-12 v2.0 scores range, 0-100, 100 indicates best functioning) | 3, 6, 12 months after surgery | 
| The impact of chronic postoperative pain on sleep quality | Pittsburgh Sleep Quality Index (PSQI score range, 0-21, 21 indicates worst sleep quality) | 3, 6, 12 months after surgery | 
| The impact of chronic postoperative pain on emotional wellbeing | Hospital Anxiety and Depression Scale (HADS score range, 0-21, 21 indicates worst anxiety or depression) | 3, 6, 12 months after surgery | 
| The impact of chronic postoperative pain on self-efficacy | Pain Self Efficacy Questionnaire (PSEQ score range, 0-60, 60 indicates strongest self-belief) | 3, 6, 12 months after surgery |