Objective: To determine (1) how the specific muscle undergoing surgical treatment affects the occurrence of the oculocardiac reflex (OCR) and oculorespiratory reflex (ORR) and (2) whether the depth of anesthesia influences the occurrence of the OCR and ORR in patients undergoing strabismus surgery with a laryngeal mask airway with maintenance of spontaneous respiration.
Methods: The medical records of patients who underwent strabismus surgery on the lateral rectus (LR) and medial rectus (MR) muscles from January 2017 to December 2017 were retrospectively reviewed.
Results: The incidence of the OCR was not significantly different between LR and MR operations in either pediatric or adult patients. The incidence of the ORR as indexed by the tidal volume (TV) was significantly higher during MR than LR surgery in pediatric patients (29.3% vs. 10.1%, respectively). The change in TV during muscle traction and the bispectral index were significantly correlated in both pediatric and adult patients (r2 = 0.034 and 0.058, respectively).
Conclusions: The OCR was not influenced by the specific muscle undergoing surgery or the depth of anesthesia. The incidence of the ORR as indexed by the TV was higher during MR surgery in pediatric patients and was positively correlated with the depth of anesthesia.
Keywords: Strabismus surgery; depth of anesthesia; laryngeal mask airway; oculocardiac reflex; oculorespiratory reflex; spontaneous respiration.