Two Intravenous Doses of Ketamine in Reducing the Oculocardiac Reflex in Adult Patients Undergoing Ophthalmic Surgery
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: 0.5 mg/kg intravenous ketamine, 0.75 mg/kg intravenous ketamine.
- Who it may be relevant to
- Registry conditions: Ketamine, Oculocardiac Reflex, Ophthalmic Surgery. Basic parameters: 18 years — 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Egypt
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Evaluation of Two Intravenous Doses of Ketamine in Reducing the Oculocardiac Reflex in Adult Patients Undergoing Ophthalmic Surgery: A Randomized Controlled Double-Blinded Trial
Overview
This study aims to evaluate whether a lower dose of ketamine (0.5 mg/kg IV) may be as effective as a higher dose (0.75 mg/kg IV) in reducing oculocardiac reflex (OCR) incidence in adult patients undergoing ophthalmic surgery.
Detailed description
The oculocardiac reflex (OCR) is a trigeminovagal reflex that can occur intraoperatively due to traction on extraocular muscles or pressure on the globe, resulting in bradycardia, arrhythmias, or asystole. Defined as a heart rate drop exceeding 20% from baseline, OCR is most frequently described in pediatric strabismus surgery, though its relevance persists in adult ophthalmic interventions involving similar stimuli.
Optimal ketamine dosing in adults remains underexplored. Higher doses may enhance OCR protection but could also prolong emergence or increase psychomimetic effects.
Interventions
- Drug 0.5 mg/kg intravenous ketamine
Patients will receive 0.5 mg/kg intravenous ketamine hydrochloride. - Drug 0.75 mg/kg intravenous ketamine
Patients will receive 0.75 mg/kg intravenous ketamine hydrochloride.
Primary outcome measures
- Incidence of oculocardiac reflex [Time frame: During extraocular muscle traction (intraoperative)]
Secondary outcome measures (6)
- Lowest recorded intraoperative heart rate [Time frame: Intraoperatively]
- Incidence of use of atropine [Time frame: Intraoperatively]
- Mean arterial pressure [Time frame: Every 15 minutes till the end of surgery (Up to two hours)]
- Heart rate [Time frame: Every 15 minutes till the end of surgery (Up to two hours)]
- Time to emergence [Time frame: To eye opening (Up to one hour)]
- Incidence of postoperative complications [Time frame: 24 hours postoperatively]
Eligibility criteria
Inclusion criteria
- Age from 18 to 65 years old.
- Both sexes.
- American Society of Anesthesiologists (ASA) physical status I, II.
- Scheduled for elective ophthalmic surgery involving extraocular muscle traction under general anesthesia.
Exclusion criteria
- Ketamine contraindications (e.g., hypersensitivity, uncontrolled hypertension)
- History of cardiac arrhythmia or conduction disorder
- Glaucoma or raised intraocular pressure
- ASA status greater than II
- Patient refusal.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
Egypt · 1 center
- Cairo University — Cairo
Identifiers
NCT: NCT07708740 · MS-139-2026 (20-6-2026)