Effect of Warm Bupivacaine on Subtenon Block.

NCT07085481 | Completed

• 1 other identifier: Warm Bupivacaine for eye block
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

Sub-Tenon's anesthesia is now widely regarded as a preferred local anesthetic method for cataract surgery. Various techniques have been explored to prolong the duration, shorten onset time and improve the efficacy of local anesthetic nerve blocks with varying degrees of success. Warming local anesthetic may speed up its onset and prolong its effect by lowering its pKa.The aim of this study is to evaluate the effect of warming bupivacaine on the characteristics of a sub-Tenon's block in patients undergoing cataract surgery. It is hypothesized that warming bupivacaine 0.5% to 37°C will improve the characteristics of sub-Tenon's block. It will prolong the duration of sensory and motor block and accelerate the time onset time of sensory and motor block.

Conditions

Cataract

Keywords

sub tenon, bupivacaine, sensory block, temperature

Outcome Measures

Primary Outcomes (1)

• the time to onset of sensory block

  Sensory block (loss of sensation in the conjunctiva and sclera and indirectly optic nerve block) will be evaluated by touch the conjunctiva using cotton wisp or forceps in the inferior fornix and ask patient if they feel it, on a 3-point scale 0= No sensation (complete block) 1= reduction in sensation 2= on loss of sensation (no block), with identical contralateral testing as reference. Ask about vision or light perception; if the optic nerve is partially blocked, the patient may report blurred or lost vision- full optic nerve block causes temporary vision loss. The time to sensory block onset (the time elapsed from the end of injection and start of the loss of sensation score =1)

  Sensory blockade will be evaluated at 1, 2, 4, 6, 8, 10 and 15 minutes after injection, and then every 30 minutes after the end of surgery for 6 hours and end of block duration is defined by return of sensation.

Secondary Outcomes (9)

• time to complete sensory block

  Sensory blockade will be evaluated at 1, 2, 4, 6, 8, 10 and 15 minutes after injection, and then every 30 minutes after the end of surgery for 6 hours and end of block duration is defined by return of sensation

• duration of sensory block

  Sensory blockade will be evaluated at 1, 2, 4, 6, 8, 10 and 15 minutes after injection, and then every 30 minutes after the end of surgery for 6 hours and end of block duration is defined by return of sensation

• The time to motor block onset

  motor blockade will be evaluated at 1, 2, 4, 6, 8, 10 and 15 minutes after injection, and then every 30 minutes after the end of surgery for 6 hours

• time to complete motor block

  motor blockade will be evaluated at 1, 2, 4, 6, 8, 10 and 15 minutes after injection, and then every 30 minutes after the end of surgery for 6 hours

• duration of motor block

  motor blockade will be evaluated at 1, 2, 4, 6, 8, 10 and 15 minutes after injection, and then every 30 minutes after the end of surgery for 6 hours

Study Arms (2)

Operating room temperature bupivacaine

EXPERIMENTAL

patients will receive local anesthetic (5ml containing 5mg bupivacaine) that will be on a sterile shelf in the operating room at 23°C. The empty syringes and needles will be also on the same shelf before their use.

Drug: room temperature Bupivacaine

Warm bupivacaine

EXPERIMENTAL

patients will receive local anesthetic (5ml containing 5mg bupivacaine) warmed to 37◦C for 20 minutes. The empty syringes and needles, in their packaging, will be held at the same temperature for at least 2 hours before initiating the block.

Drug: warm Bupivacaine

Interventions

room temperature Bupivacaine DRUG

bupivacaine will be on a sterile shelf in the operating room at 23°C. The empty syringes and needles will be also on the same shelf before their use.

Also known as: Non-warmed bupivacaine

Operating room temperature bupivacaine

warm Bupivacaine DRUG

bupivacaine will be warmed to 37◦C for 20 minutes. The empty syringes and needles, in their packaging, will be held at the same temperature for at least 2 hours before initiating the block.

Also known as: Pre-heated bupivacaine

Warm bupivacaine

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• American Society of Anesthesiology (ASA) I, II or III patients.
• Patients scheduled for elective unilateral cataract surgery.

You may not qualify if:

• Patient refusal to participate in the study.
• Altered mental status or un-cooperative patients or psychiatric disorder.
• History of anesthetic drug allergy.
• Pre-existing progressive demyelinating neurologic pathology or neuromuscular disorders.
• Any contraindications to block (as bleeding or coagulation diathesis).

Sponsors & Collaborators

• Mansoura University: lead

Study Sites (1)

Mansoura University

Al Mansurah, 35511, Egypt

Location

Related Links

• The effect of warming ropivacaine on ultrasound-guided subgluteal sciatic nerve block: a randomized controlled trial
• The Influence of Bupivacaine Temperature on Supraclavicular Plexus Block Characteristics: A Randomized, Controlled Trial
• The effect of warming ropivacaine on ultrasound-guided subgluteal sciatic nerve block: a randomized controlled trial
• Effect of temperature and pH adjustment of bupivacaine for intradermal anesthesia

MeSH Terms

Conditions

Cataract

Condition Hierarchy (Ancestors)

Lens Diseases; Eye Diseases

Study Officials

• Amany H ELDeeb, MD

  Faculty of Medicine, Mansoura University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: A single investigator who will not be involved in the further study steps or data collection will assess the patients for eligibility, explain the study protocol and anesthetic technique, obtain written informed consent, open the sealed opaque envelopes containing group allocation, prepare all solutions for each block identical syringe, and handle the syringes during the injection process. The investigator who will perform the block will be blinded to group allocation and will be allowed to enter the operative room after preparation of the injection solution. In addition, the study subjects and the investigator who will collect the data will be blinded to the study group. To maintain blinding, the block administrator will wear gloves, and the solution will be administered within 40 seconds of preparation to minimize temperature perception.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: lecturer of anaesthesia and intensive care, faculty of medicine

Model Details: Prospective, randomized, double blind study

Study Record Dates

• First Submitted: July 18, 2025
• First Posted: July 25, 2025
• Study Start: October 1, 2025
• Primary Completion: December 30, 2025
• Study Completion: January 20, 2026
• Last Updated: January 27, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)