Clinical trial NCT04668456: Subtenon and Intravenous Dexmedetomidine Effect on Patients Undergoing Cataract Surgery
Official title: The Effect of Subtenon and Intravenous Dexmedetomidine on Patients Undergoing Cataract Surgery: A Comparative Randomized Controlled Double Blind Study
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE3
Conditions: Acute Postoperative Pain
Keywords: subtenon
dexmedetomidine
cataract surgery
Lead sponsor: Menoufia University
Sponsor class: OTHER
First posted: 2020-12-16
Enrollment: 75
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: 75 Patients were assigned into three equal groups, all patients received 2.5 ml of local anesthetic mixture through subtenon block and IV infusion of drugs as follows: Group C (control group): received subtenon LA mixture of bupivacaine 0.5% (1 ml) + lidocaine 2% (1 ml)+ saline 0.9% (0.5 ml) and IV infusion of saline 0.9% over 10 min. before subtenon block.

Group SD ( subtenon dexmedetomidine): received subtenon LA mixture of bupivacaine 0.5% (1 ml) + lidocaine 2% (1 ml)+ 0.5 μg/kg dexmedetomidine (0.5 ml) and IV infusion of saline 0.9% over 10 min. before subtenon block.

Group ID (iv dexmedetomidine): received received subtenon LA mixture of bupivacaine 0.5% (1 ml) + lidocaine 2% (1 ml)+ saline 0.9% (0.5 ml) and IV infusion of 0.5 μg/kg dexmedetomidine over 10 min. before subtenon block.
Primary purpose: TREATMENT

Brief summary: The study designed to compare the effects and the safety of adding dexmedetomidine to local anesthetics and its intravenous administration in subtenon block in patients undergoing cataract surgery.

Detailed description: Ophthalmological surgery can be performed under topical, regional or general anesthesia. Recently, the majority of ocular surgeries performed by regional rather than general anesthesia, because of the regional anesthesia is more economic, easy to perform, and the risk involved is less. Orbital regional anesthesia can be done using a retrobulbar (intra-conal) block, peribulbar (extra-conal) block or sub-Tenon's block.

The STBs or episcleral block was first described by Turnbull in 1884 and it was repopularized in the 1990s as a simple and safe alternative to needle-based eye blocks. The STB becomes the most widely practiced regional technique for cataract surgery, because it produces satisfactory anesthesia for most intraocular procedures, and avoids the inherent risks of needle-based blocks, such as globe perforation and optic nerve injury.

Dexmedetomidine is a selective α-2 receptor agonist that produces sedation and analgesia without causing respiratory depression. It also allows patients to respond to verbal commands during the sedation; easy conversion from sleeping to awakening is possible. Therefore, dexmedetomidine has been used as sedative in various clinical fields in intensive care unit and surgery and an adjuvant to local anesthetics.

Many studies were done to evaluate its effect as sedative or anlgesic when administered either intravenously or when added to local anesthesia in ophthalmic block. But no one, till now comparing its effect when used as adjuvant to local anesthetics or administered intravenously in subtenon block.

Eligibility criteria: Inclusion Criteria:

* ASA grade I-III
* Aged 18-70 years
* Both sex
* Scheduled for elective phacoemulsification cataract surgery

Exclusion Criteria:

* Coagulation abnormalities
* Impaired mental status
* Refusal of the patient
* Uncontrolled glaucoma
* Recent surgical procedure on the same eye

Primary outcomes:
measure: duration of sensory block
timeFrame: 24 hours
Secondary outcomes:
measure: duration of motor block
timeFrame: 24 hours
Other outcomes:
Locations:
city: Shibīn Al Kawm
country: Egypt
facility: Ashraf magdy Eskandr
state: Menoufiya
city: Shibīn Al Kawm
country: Egypt
facility: Osama A Elmorsy
state: Menoufiya
city: Shibīn Al Kawm
country: Egypt
facility: Sadik A Sadik
state: Menoufiya
Study officials:
References: