The intraoperative oculocardiac reflex as a predictor of postoperative vaso-vagal responses during adjustable suture...

Adjustable suture surgery has become a popular method of strabismus correction in those cases in which results are less predictable, such as reoperations, thyroid ophthalmopathy, and blind eyes. Complications related to adjustable strabismus surgery are, in general, no different than those related to standard surgical techniques. We noticed a subgroup of patients who experienced significant vaso-vagal responses (V-VR) during postoperative adjustment and sought to discover a method of identifying these patients prior to adjustment. Sixty patients were studied prospectively from July 1991 to July 1992. All patients had surgery under general anesthesia and were adjusted 24 hours later. A positive oculocardiac reflex (OCR) occurred when a 10% or greater intraoperative change in heart rate was associated with traction on an extraocular muscle. A positive V-VR postoperatively consisted of one or more subjective findings (dizziness, light-headedness, nausea, or body temperature changes), and two or more objective findings (10% or greater change in heart rate, hypotension, pallor, diaphoresis, vomiting, disorientation, or loss of consciousness). Variables studied for predictive value included OCR, age, sex, strabismus type, previous surgery, muscle adjusted, and systemic disease. Twenty-five patients (41.6%) had a positive V-VR during adjustment. Twenty-seven patients (45%) had a positive OCR. Eighty-five percent of patients with a positive OCR and 9% of patients with a negative OCR had a positive V-VR. Younger patients were also more likely to have a positive V-VR. A positive intraoperative OCR under general anesthesia during strabismus surgery is highly predictive of a postoperative V-VR during planned adjustment.