Assessment of the Effect of Clonidine for Cataract Surgery

Study Overview
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Brief Summary
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Clonidine, an agonist for alfa2 pre-synaptic, has been shown to be an effective adjuvant therapy for acute postoperative pain and has been shown an effect in sedative, intra-ocular and blood pressure and arrhythmias.The objective of this study is evaluating the analgesic effect of clonidine and its repercussion on arterial and intraocular pressure and arrhythmias for cataract surgery.

Detailed Description
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After approved by the Ethical Committee and signed informed consent, 40 patients aged from 40 until 80 years undergoing cataract extraction will be randomized in two groups. Exclusion criteria will be myocardial ischemia, psychiatric disease, chronic pain, drugs dependency, chronic use of beta-blockage channel drugs. Group 2, patients will receive a single dose of 4mcg.kg-1 of clonidin2, 20 minutes before the surgical incision; group 1, patients will receive a sterile saline solution dose. Pain intensity will be assessed with the numeric rating scale. The antiarrythmic effect will be assessed with the continuous measure by Holter. The number of patients was calculated by Instat Graph® program. To detect difference in pain intensity of 3 between the groups by NRS, with 95% of power (estimated SD= 2.0), when the alpha level is set at 0.05, the sample should be of 20. Statistical analyses will be performed with parametric and nonparametric tests, considering the variety studied. The statistical program that will be utilized is Instat Graph®.

Official Title
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Assessment of the Effect of Clonidine on Pain, Arterial and Intraocular Pressure and Arrhythmias for Cataract Surgery

Conditions
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Pain, Arrythmia

Intervention / Treatment
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* Drug: Clonidine
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: cataract surgery topical anesthesia Exclusion Criteria: myocardial ischemia psychiatric disease chronic pain drugs dependency use of beta-blockage channel drugs

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 80 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: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: group 2: clonidine 4mcg.kg<br>this group (group 2) will receive 4mcg.kg-1 of clonidine 20 minutes before surgery. | Drug: Clonidine<br>* 4 mcg.kg-1, 20 minutes before cataract surgery<br>* Other names: anesthesic drugs;|
| Placebo Comparator: Group 1: sterile saline solution<br>this group (Group 1) will receive a sample injection of sterile saline solution 20 minutes before surgery | Drug: placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| intensity of pain | Pain intensity will be assessed by numeric rating scale. | 30 minutes before surgery, during the surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| intraocular pressure | Intra-ocular pressure will be assessed with a manual tonometer of perkins. | 30 minutes and during the surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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clonidine, cataract surgery, arrythmia, anesthesic medication