Minimum Effective Volume of Local Anesthetic for Peribulbar Block.Does it Differ With the Eyeball Axial Length?

Study Overview
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Brief Summary
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The aim of this study is to calculate the minimum effective volume of local anesthetic for peribulbar block in patients undergoing cataract extraction surgery.

Detailed Description
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The main goal of this study is to estimate the minimum effective volume(MEV90) of local anesthetic and hyaluronic acid given for local anesthesia of the eye for 2 different axial length groups of patients undergoing eye surgery. Volume assignment was carried out using a biased coin design (BCD) up-and-down sequential method (UDM), where the volume given to each patient depends on the response of the previous one. The MEV90 was calculated using isotonic regression with bias-corrected 95% confidence interval (CI) derived by boots trapping. The mean value of the estimate was obtained from 3000 bootstrap samples.

Official Title
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Minimum Effective Volume of Local Anesthetic for Peribulbar Block.Does it Differ With the Eyeball Axial Length?

Conditions
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Peribulbar Block

Intervention / Treatment
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* Drug: Bupivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: we allocated adult patients aged 40-70 years, of both gender, American Society of Anesthesiologists (ASA) II - III, listed for elective cataract extraction using phaco emulsification technique with intraocular lens implantation surgery. Exclusion Criteria: Patients known to have any systemic contraindications (as severe hypertension) or allergy to the local anesthetic, those who refused local anesthesia, high myopes (axial length > 26 mm), patients with a single eye, those with complicated vitreous hemorrhage, ocular infection, or associated glaucoma have been excluded.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 70 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: Health Services Research
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 1(22-24 mm)<br>Group 1 (patients with axial length between 22 and 24 mm): received a mixture of bupivacaine 0.5% (3ml) + lidocaine 2% (3ml) + hyalurindase 150 IU (1 ml) to a total volume of 7 ml. | Drug: Bupivacaine<br>* peribulbar block<br>* Other names: hyaluronic acid;|
| Experimental: Group 2(24.1-26 mm)<br>Group 2 (patients with axial length between 24.1 and 26 mm): received a mixture of bupivacaine 0.5% (3ml) + lidocaine 2% (3ml) + hyaluronidase 150 IU (1 ml) to a total volume of 7 m | Drug: Bupivacaine<br>* peribulbar block<br>* Other names: hyaluronic acid;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The minimum effective volume of local anesthetic of the eye in relation to the eyeball axial length. | The minimum effective volume of local anesthetic in peribulbar block in relation to the eyeball axial length.The minimum volume which will achieve adequate sensory and motor block within 10 minutes. | 10 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peribulbar block, minimum effective volume, axial eye length