The Alaska Oculocardiac Reflex Study

Study Overview
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Brief Summary
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Observation study monitoring vital signs and anesthetic variables particularly heart rate during prospective, ocular manipulation and specifically uniform tension on extra ocular muscles during strabismus surgery. *IRB approval from 1992 covered in letter from then IRB chair Dr. Judith Whitcomb, Anchorage, Alaska (letter 10/2020).*

Detailed Description
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Patients with ocular manipulation including those scheduled for strabismus surgery will have peri-operative variables monitored before, during and after uniform traction on extra ocular muscles (EOM). The oculocardiac reflex (OCR) will be elicited by quantified (200 gram, 10-second, square-wave) traction on Jameson muscle hook under insertion of an extra ocular muscle (EOM, rectus). Stable pre-tension heart rate, and greatest change heart rate will be recorded. Additional variables to be recorded: birthdate, gender, race, weight, iris color, pre-operative neurodevelopmental conditions, pre-operative medications, induction medications, expired carbon dioxide (CO2) levels, exhaled gas concentrations, anticholinergic medications, opioids, muscle relaxants, type of airway and the number of EOM operated.

Official Title
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The Alaska Oculocardiac Reflex Study

Conditions
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Bradycardia, Strabismus

Intervention / Treatment
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* Diagnostic Test: electrocardiograph


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient scheduled for ocular manipulation and tension on extra ocular muscles and strabismus surgery Exclusion Criteria: anophthalmia

Ages Eligible for Study
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Minimum Age: 1 Month
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| anticholinergic<br>Patients who receive anticholinergic medication before strabismus surgery | Diagnostic Test: electrocardiograph<br>* electrocardiograph monitor during strabismus surgery<br>* Other names: ECG, EKG;|
| non-anticholinergic<br>Patients who do not received anticholinergic medication before strabismus surgery | Diagnostic Test: electrocardiograph<br>* electrocardiograph monitor during strabismus surgery<br>* Other names: ECG, EKG;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent heart rate resulting from oculocardiac reflex | Continuous variable of percent change in heart rate from stable pre-heart rate to greatest change heart rate during strabismus surgery | 30 seconds | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anesthetic interventions | Impact of existing and emerging anesthetics on oculocardiac reflex. This shall include various existing and emerging medications and inhalation agents, dosage, routes, airway types, general anesthesia and awake, and monitor methods. | 2 hours | 
| Patient Characteristics | The impact of various patient characteristics on oculocardiac reflex including patient age, weight, gender and race, the presence of neuro-developmental condition. | 2 hours | 
| Surgeon Interventions | The impact of various aspects/phases of ocular manipulation and/or surgical technique. This includes monitored electrocardiograph during insertion of lid speculum, pressure on the globe, grasping of conjunctiva, incision of conjunctiva, dissection of Tenon's capsule, traction on extra ocular muscle, suturing extra ocular muscle, disinsertion of extra ocular muscle, re-suturing of extra ocular muscle and closure of conjunctiva. | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oculocardiac reflex