Influence of Intraoperative Analgesia on the Postoperative Morphine Consumption

Study Overview
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Brief Summary
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Unlike longer acting opiates (sufentanil), remifentanil may provoke postoperative hyperalgesia. We have developed two automated bispectral index - guided drug delivery systems: one for propofol administration, the other for combined propofol and remifentanil administration. Both systems achieve the same objective: similar level of anesthesia indicated by bispectral index levels between 40 to 60. We make the assumption that this method of automated remifentanil administration may avoid postoperative hyperalgesia. Patients scheduled for abdominal surgery will be divided into two groups: in one group, patients will receive automatically delivered propofol and manually delivered sufentanil according to the usual criteria, in the other group, patients will receive propofol and remifentanil both automatically administered. Assessment of postoperative hyperalgesia will be primarily based on morphine consumption (patient controlled analgesia) and detection of cutaneous hyperalgesia areas.

Official Title
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Influence of Intraoperative Analgesia (Sufentanil Administered According to the Usual Criteria or Remifentanil Administered by a Closed-loop System Using Bispectral Index as the Controller) on the Postoperative Morphine Consumption

Conditions
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Anesthesia

Intervention / Treatment
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* Drug: Remifentanil
* Drug: Sufentanil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Patients scheduled for an abdominal surgery Exclusion Criteria: Age less than 18 years, Pregnant women, Allergy to propofol, sufentanil, remifentanil, morphine, muscle relaxant, or to a component, Hypersensibility to sufentanil, remifentanil or to a derivate of fentanyl, Inflammatory bowel disease, Chronic pain, Patients receiving a psychotropic treatment or a a morphine agonist-antagonist, Alcoholic patients and patients taking opiates, History of neurological disorders or central brain lesion, of severe respiratory insufficiency, of hepatic insufficiency, Emergency surgery

Ages Eligible for Study
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Minimum Age: 18 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>Patients will receive propofol and remifentanil automatically administered (closed-loop administration using bispectral index as the single input for the controller). | Drug: Remifentanil<br>* closed-loop administration using bispectral index as the single input for the controller.<br>|
| Active Comparator: 2<br>Patients will receive propofol automatically administered (closed-loop administration using bispectral index as the single input for the controller) and sufentanil according to usual criteria | Drug: Sufentanil<br>* dosage according to usual criteria<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dose of morphine administered during the postoperative period (patient controlled analgesia) |  | 48 postoperative hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| postoperative pain scores |  | 48 postoperative hours | 
| postoperative hyperalgesia |  | up to 5th to 7th postoperative days | 
| nausea vomiting |  | 48 postoperative hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Analgesia, Patient-Controlled Analgesia, Hyperalgesia, Anesthesia