Assessment of the Effect of Clonidine for Cataract Surgery
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.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
|Official Title:||Assessment of the Effect of Clonidine on Pain, Arterial and Intraocular Pressure and Arrhythmias for Cataract Surgery|
- intensity of pain [ Time Frame: 30 minutes before surgery, during the surgery ] [ Designated as safety issue: Yes ]Pain intensity will be assessed by numeric rating scale.
- intraocular pressure [ Time Frame: 30 minutes and during the surgery ] [ Designated as safety issue: Yes ]Intra-ocular pressure will be assessed with a manual tonometer of perkins.
- antiarrythmic effect [ Time Frame: 30 minutes before surgery and during the surgery ] [ Designated as safety issue: Yes ]The antiarrythmic effect will be assessed with the continuous measure by Holter.
- blood pressure [ Time Frame: 30 minutes before and during the surgery ] [ Designated as safety issue: Yes ]Blood pressure will be monitorized with a multiparameter monitor, a non-invasive measure.
|Study Start Date:||July 2011|
|Estimated Study Completion Date:||December 2012|
|Estimated Primary Completion Date:||September 2012 (Final data collection date for primary outcome measure)|
Active Comparator: group 2: clonidine 4mcg.kg
this group (group 2) will receive 4mcg.kg-1 of clonidine 20 minutes before surgery.
4 mcg.kg-1, 20 minutes before cataract surgery
Placebo Comparator: Group 1: sterile saline solution
this group (Group 1) will receive a sample injection of sterile saline solution 20 minutes before surgery
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®.
|Federal University of Sao Paulo||Recruiting|
|Sao Paulo, Brazil|
|Contact: Ana Ellen Santiago, investigator 55 1 69 9334 4747 email@example.com|
|Principal Investigator: Ana Ellen Santiago, investigator|
|Study Chair:||Rioko K Sakata, Study Chair||Federal University of Sao Paulo|