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Subtenon and Intravenous Dexmedetomidine Effect on Patients Undergoing Cataract Surgery

Phase 3
Conditions
Acute Postoperative Pain
Interventions
Drug: bupivacine 0.5%
Drug: Normal saline
Registration Number
NCT04668456
Lead Sponsor
Menoufia University
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.

Recruitment & Eligibility

Status
UNKNOWN
Sex
All
Target Recruitment
75
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Group ID (iv dexmedetomidine)lidocaine 2%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.
Group C (control group)bupivacine 0.5%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 C (control group)Normal salineGroup 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 dexmedetomiine)Normal salineGroup 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 C (control group)lidocaine 2%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 dexmedetomiine)lidocaine 2%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 SD (subtenon dexmedetomiine)bupivacine 0.5%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)bupivacine 0.5%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.
Group SD (subtenon dexmedetomiine)DexmedetomidineGroup 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)DexmedetomidineGroup 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 Outcome Measures
NameTimeMethod
duration of sensory block24 hours

time from injection of local anesthetic mixture to complete recovery from pain sensation or the first need of rescue analgesia

Secondary Outcome Measures
NameTimeMethod
duration of motor block24 hours

time from injection of local anesthetic to complete recovery of motor function in all ocular muscles.

Trial Locations

Locations (3)

Sadik A Sadik

🇪🇬

Shibīn Al Kawm, Menoufiya, Egypt

Ashraf magdy Eskandr

🇪🇬

Shibīn Al Kawm, Menoufiya, Egypt

Osama A Elmorsy

🇪🇬

Shibīn Al Kawm, Menoufiya, Egypt

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