Morphine Postoperative Analgesia and Pharmacokinetic/Pharmacodynamic Modeling

Study Overview
=================
Brief Summary
-----------------
The currently available data are insufficient to develop a model that achieves optimum morphine dose individualization at the postoperative period of coronary artery bypass grafting (CABG). Therefore, the objective of the study was to apply a PK/PD model that could justify morphine consumption, drug plasma concentration and pain intensity during the postoperative period after CABG and evaluate the post operative pain.

Detailed Description
-----------------
The protocol was a prospective, open-label study, approved by the institutional ethical committee of the hospital where the study was performed. Patients were randomly assigned to receive general anesthesia plus intrathecal morphine at a dosage of 400 mcg (morphine group) or general anesthesia alone (control group) according to a simple computer-generated list.

Official Title
-----------------
Pharmacokinetic/Pharmacodynamic Modeling of Morphine for Postoperative Analgesia Through a Patient Controlled Device After Coronary Artery Bypass Grafting. Intrathecal Morphine Significantly Reduces Drug Consumption

Conditions
-----------------
Cardiopulmonar Artery Bypass Grafting

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: eligible to cardiopulmonary artery bypass grafting surgery Exclusion Criteria: fraction of ejection below 40% contraindications to neuraxial blockage coagulopathy use of low-weight heparin warfarin or a platelet aggregation inhibitor other than aspirin, systemic or local infection and patients with a specific contraindication on the medication employed in the study

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Intrathecal morphine<br>Patients were randomized for general anesthesia, and allocated in the control group and morphine intrathecal group. | |
| Control group<br> | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain | From the end of surgery until 36 hours of postoperative period | two days | 
| PK/PD modelling | From the begin of surgery until 36 hours of postoperative period | 2 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PK parameter: Cmax (peak plasma concentration) | from the begin of surgery until 36 hours of postoperative period | 2 days | 
| PK parameter: Tmax (time to achieve the maximum concentration) | from the begin of surgery until 36 hours of postoperative period | 2 days | 
| PK parameter: AUC (area under the plasma cocentration versus time curve) | from the begin of surgery until 36 hours of postoperative period | 2 days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
pharmacokinetic/pharmacodynamic modeling, intrathecal morphine, postoperative analgesia, patient-controlled analgesia device