A 5-year-old child undergoing strabismus surgery under general anesthesia suddenly develops sinus bradycardia and intermittent ventricular escape beats but is hemodynamically stable. Which therapy is appropriate?

A 5-year-old child undergoing strabismus surgery under general anesthesia suddenly develops sinus bradycardia and intermittent ventricular escape beats but is hemodynamically stable. Which therapy is appropriate?

• A. Tell the surgeon to stop pulling on the eye muscle
• B. Tell the surgeon to do a retrobulbar block
• C. Change from halothane to sevoflurane
• D. Decrease the depth of the volatile anesthetic

Answer: (A)

The situation illustrates the oculocardiac reflex, a trigeminal-vagal reflex triggered by traction on extraocular muscles during eye surgery. When the eye muscle is pulled, afferent signals travel via the ophthalmic division of the trigeminal nerve to the brainstem, and efferent vagal output slows the heart, causing sinus bradycardia and sometimes ventricular ectopy. If the patient remains hemodynamically stable, the immediate and most effective step is to remove the stimulus by asking the surgeon to stop pulling on the eye muscle. This often reverses the bradycardia promptly. If bradycardia persists, treatment with an anticholinergic such as atropine can be given. Preventive or alternative strategies like performing a retrobulbar block could blunt the reflex, but it is not the first anticipated action during active manipulation due to its own risks and the need for time to perform. Simply changing to a different volatile agent or decreasing the depth of anesthesia does not address the underlying trigger and may not reliably prevent or reverse the reflex.

The situation illustrates the oculocardiac reflex, a trigeminal-vagal reflex triggered by traction on extraocular muscles during eye surgery. When the eye muscle is pulled, afferent signals travel via the ophthalmic division of the trigeminal nerve to the brainstem, and efferent vagal output slows the heart, causing sinus bradycardia and sometimes ventricular ectopy. If the patient remains hemodynamically stable, the immediate and most effective step is to remove the stimulus by asking the surgeon to stop pulling on the eye muscle. This often reverses the bradycardia promptly. If bradycardia persists, treatment with an anticholinergic such as atropine can be given.

Preventive or alternative strategies like performing a retrobulbar block could blunt the reflex, but it is not the first anticipated action during active manipulation due to its own risks and the need for time to perform. Simply changing to a different volatile agent or decreasing the depth of anesthesia does not address the underlying trigger and may not reliably prevent or reverse the reflex.