The physiological response known as oculocardiac reflex identifies a unique decrease in pulse rate associated with any traction of the extraocular muscles or compression of the eyeball itself. This is particularly relevant to paramedics who are treating a patient with an injury who becomes bradycardic. The phenomenon is rarely seen out through accidental trauma and is most commonly seen during eye surgery, particularly in neonates and children.
What Causes Oculocardiac Reflex?
Oculocardiac reflex is caused by stimulation of the vagus nerve which is closely interconnected with the trigeminal cranial nerves, resulting in parasympathetic stimulation and subsequent brady-dysrhythmias.
As a paramedic it is important to consider oculocardiac reflex in any patient with a traumatic injury to the eye that may result in any traction of the extraocular muscles or compression of the eyeball itself. A cardiac monitor should be used with these patients and closely observed for signs of bradycardia.
Treatment of oculocardiac reflex by paramedics and within hospitals involves immediately removing the stimulus that is causing the pressure on the vagus nerve. This generally results in the restoration of sinus rhythm. If unsuccessful, treatment options should consider anticholinergic medications such as atropine. In very rare circumstances, severe bradycardias and assystole may result requiring external cardiac pacing (or CPR).