Effect of Combination Dexmedetomidine Added to Fentanyl-based Intravenous Patient-controlled Analgesia on Nausea Vomiting in Highly Susceptible Patients Undergoing Lumbar Spinal Surgery: Prospective Double Blinded Randomized Controlled Trial

Study Overview
=================
Brief Summary
-----------------
The aim of this study is to test the hypothesis that addition of dexmedetomidine to fentanyl-based intravenous patient controlled analgesia (PCA) reduces requirement of fentanyl bolus and consequent postoperative nausea and vomiting in high-risk patients undergoing lumbar spine surgery.

Conditions
-----------------
PONV

Intervention / Treatment
-----------------
* Drug: dexmedetomidine
* Drug: normal saline


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 1. female, non-smoking patient who are 20-65 of age scheduled for elective lumbar spine surgery Exclusion Criteria: Bradycardia on EKG (45bpm) Atrioventricular conduction disorder Uncontrolled hypertension angina history obesity (BMI ≥ 30 kg/m2) Preoperative administration of opioid Preoperative administration of antiemetics Gastrointestinal disorder history Hepatic or renal disease Pregnant 11. Foreigner

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
Female

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

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

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: dexmedetomidine<br>addition of dexmedetomidine to fentanyl-based intravenous patient controlled analgesia (PCA) | Drug: dexmedetomidine<br> <br> |
| Placebo Comparator: normal saline<br>normal saline as a placebo | Drug: normal saline<br> <br> |

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| total dose and bolus administration of opioid | After induction of anesthesia, peak velocity of carotid artery blood flow is measured by the pulsed wave Doppler signal obtained from the left common carotid artery. Respirophasic variation of the peak velocity is defined as the difference between the maximum and the minimum values of peak velocity divided by the mean of the two values during one respiratory cycle. Fluid responder is defined as a patient whose stroke volume index is increased ≥15% after volume expansion. The receiver operating characteristic curve analysis to discriminiate fludi responder is performed. | an expected average of 48 hrs for requirements of total dose and number of bolus administration of PCA | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| consequent postoperative nausea and vomiting | After induction of anesthesia, peak velocity of carotid artery blood flow is measured by the pulsed wave Doppler signal obtained from the left common carotid artery. Respirophasic variation of the peak velocity is defined as the difference between the maximum and the minimum values of peak velocity divided by the mean of the two values during one respiratory cycle. Fluid responder is defined as a patient whose stroke volume index is increased ≥15% after volume expansion. The receiver operating characteristic curve analysis to discriminate fluid responder is performed. | an expected average of 48 hrs for assessing of the 11-points verbal numerical rating scales | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
PONV, IV PCA, dexmedetomidine, Female, non-smoking, lumbar spine surgery