Antagonism Research Between Antiemetics Agents and Acetaminophen in Thyroidectomy's Post-operative Analgesia.

Study Overview
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Brief Summary
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The purpose of our study is to determine if there is an antagonism between drugs used in the prevention of postoperative nausea and vomiting (PONV) on the analgesia led by acetaminophen after thyroidectomy.

Detailed Description
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It was shown that there was an antagonism of the ondansetron on the analgesia led by acetaminophen in a model of nociception by electrical stimulation using the PainMatcher in healthy volunteers. Our study try to determinate if a such antagonism exist in clinical conditions : 66 patients with an Apfel-score II undergoing thyroidectomy were randomized in 3 equal groups. Each group received an antiemetic (ondansetron, droperidol or dexamethasone) at the begining of the intervention and paracetamol at the end of the intervention for the postoperative analgesia. During 2 hours in the postoperative unit, we raised : the electrical pain's threshold with the PainMatcher, the numeric pain intensity scale and the presence of nausea or vomiting. For each patients we determined the cytochrome P450 2D6 activity that should have been able to explain a diminution of ondansetron's efficiency. Paracetamol blood levels were also raised in the postoperative unit.

Official Title
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Antagonism Research Between Antiemetics Agents (Droperidol, Dexametasone, Ondansetron) and Acetaminophen in Thyroidectomy's Post-operative Analgesia.

Conditions
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Interaction Between Antiemetic Drugs and Paracetamol

Intervention / Treatment
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* Drug: ondansetron
* Drug: Droperidol
* Drug: Dexamethasone


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients undergoing thyroidectomy without lymph node dissection American Society of Anesthesiologists physical status from I to III Apfel-score equal to 2 informed consent signed Exclusion Criteria: pregnant and breast-feeding women addictive disorders psychic diseases allergy or contra-indication to a drug used in the study presence of postoperative nausea or vomiting administration of glucocorticoid for protecting recurrent laryngeal nerve. protocol not respected protocol refused by the patient intellectual handicap

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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: ONDANSETRON (OS)<br>patients receiving ondansetron at the beginning of the surgery to prevent postoperative nausea and vomiting (PONV); and paracetamol at the end of the surgery for postoperative analgesia. | Drug: ondansetron<br>* ondansetron: 4 mg intravenous administration afer the induction of anesthesia.<br>|
| Active Comparator: DROPERIDOL (DRO)<br>patients receiving droperidol at the beginning of the surgery to prevent PONV; and paracetamol at the end of the surgey for postoperative analgesia. | Drug: Droperidol<br>* droperidol: 1.25 mg intravenous administration after the induction of anesthesia.<br>|
| Active Comparator: DEXAMETHASONE (DEXA)<br>patients receiving dexamethasone at the beginning of the surgery to prevent PONV; and paracetamol at the end of the surgey for postoperative analgesia. | Drug: Dexamethasone<br>* dexametasone: 4 mg intravenous administration after the induction of anesthesia.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| electric nociception threshold measured by PainMatcher | The PainMatcher is a pain self-assessment device using the electric stimulation of the median nerve. The patient maintains a pressure on an electrode box between the thumb and the index finger, creating a current of increasing intensity. The threshold of pain sensation is obtained when the patient releases his fingers from the electrode box. So whe raise the electric nociceptive threshold showned by the PainMatcher. We realize two measures and consider the second one. objective measure. | during 2 hours after thyroidectomy in the postoperative care unit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| numeric rating scale score | to evaluate the sensation of pain with a 11 levels going from 0 ( no pain) to 10 ( worst pain imaginable). subjective measure. | during 2 hours after thyroidectomy in the postoperative care unit | 
| need in rescue analgesia with nefopam in case of numeric rating scale score > 4 |  | during 2 hours after thyroidectomy in the postoperative care unit | 
| presence of postoperative nausea and vomiting |  | during the 2 hours after thyroidectomy in the postoperative care unit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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postoperative analgesia, paracetamol, 5-HT3 antagonist, ondansetron, PainMatcher