True about the Oculocardiac reflex includes following EXCEPT:
Ans. B. Preperative glycopyrolate is not helpful for prevention. (Ref. Miller's Anesthesia 7th/Pg. 293; Paul's Clinical Anesthesia/Pg. 1327).A variety of stimuli arising in or near the eye especially following traction on the medial rectus or pressure on the eye ball may cause bradycardia, arrhythmias and cardiac arrest. In clinical practice this oculocardiac reflex (Trigeminovagal reflex) is most often encountered during squint surgery in children. OCR is also seen during eye muscle surgery, repair of detached retina, compression of gasserian ganglion 13, enucleation of eye and by contact lens and repair of nasal fracture under General Anaesthesia. Prophylactic anti cholinergic is recommended and adequate cardiac monitoring must accompany these interventions as immediate action may be required. OCR may be manifest by bradycardia, bigeminey, ectopic beats, nodal rhythm, AV block and cardiac arrest.Oculocardiac Reflex (Trigeminovagal Reflex)# Bernard Aschner and Guiseppe Dagnini first described the oculocardiac reflex in 1 908. This reflex is triggered by pressure on the globe and by traction on the extraocular muscles, as well as on the conjunctiva or the orbital structures.# This reflex is clinically significant during strabismus surgery in children, although the manifestations of this reflex are not consistent. The oculocardiac reflex (OCR) is induced by pressure on the eyeball.# The afferent pathway follows the long and short ciliary nerves to the ciliary ganglion. From there, it travels to the gasserian ganglion body along the ophthalmic division of the trigeminal nerve (CN V). The afferent pathway ends in the main trigeminal sensory nucleus in the floor of the fourth ventricle.# Efferent impulses start at the vasomotor center and travel through the vagal nerve (CN X) and the sympathetic chain. Bradycardia is the result of increasing parasympathetic tone. Decreasing sympathetic tone causes vasodilatation.# The cardiac effect stops when eye pressure is relieved. Patients should be monitored to recognize ECG changes. Atropine should be available to reverse life-threatening bradycardia.
Mediated by trigeminovagal route
Preperative glycopyrolate is not helpful for prevetion
Induced by pressure on eye ball
Mediated by traction on medial rectus
Complications Of Anaesthesia