Postoperative Nausea and Vomit in Strabismus Surgery

Postoperative nausea and vomiting (PONV) is a major concern in paediatric inpatient surgery and may increase patient discomfort, delay patient discharge, and increase the cost of patient care. The incidence of PONV after strabismus surgery is relatively high, compared with other inpatient surgeries, particularly in children. Oculocardiac reflex (OCR) is a phenomenon defined by bradycardia or dysrhythmia during strabismus surgery. Oculocardiac reflex is commonly caused by the traction on the extraocular muscle (EOM), which, through the ophthalmic branch of trigeminal nerve, stimulates the vagal center. The afferent arm of the reflex is the ophthalmic branch of the trigeminal nerve, and the efferent arm is the vagus nerve, which diminishes sinoatrial node impulses and leads to bradycardia.While there is a general consensus regarding the role of unmodifiable risk factors for PONV, including the number of muscle and the occurrence of Oculocardiac reflex or not, the role of modifiable risk factors, such as duration of surgery and anesthesia and perioperatively administered medications, is still disputed. In the present study, the investigators evaluated whether these factors may be associated with postoperative nausea and vomiting after paediatric strabismus surgery while controlling for a range of covariates.