title: Incidence and ramifications of the oculocardiac reflex during the orbitozygomatic approach: a prospective assessment.
abstract: OBJECTIVE
  The oculocardiac reflex (OCR) is a sudden decrease in heart rate resulting from mechanical manipulation of the orbit, especially due to traction on the orbital contents. The purpose of this study was to determine the incidence and clinical ramifications of OCR elicitation by the orbitozygomatic (OZ) approach.
  
  
  METHODS
  Electrocardiographic strips were collected prospectively from 104 patients undergoing OZ approaches. Recording was started at the commencement of the craniotomy cuts and was stopped after completion of the OZ osteotomy. Each recording was divided into stage 1, which encompassed the time between the start of the craniotomy cuts to the commencement of the osteotomy cuts, and stage 2, which encompassed the time from commencement of osteotomy cuts until completion of all bone work and dural tacking Orbital manipulation occurred exclusively during stage 2. A decrease in heart rate of 10 bpm or more between stage 1 and stage 2 was recorded as an OCR event.
  
  
  RESULTS
  In our 104 patients we detected OCR events 31.7% of the time. There was no significant difference in rate of OCR occurrence found in analysis of the covariates of hypertension, hyperlidemia, diabetes mellitus, hypothyroidism/hyperthyroidism, β-blocker use, calcium channel blocker use, or tobacco use. In each case, transient cessation of orbital manipulation was sufficient to normalize heart rate. No patients required anticholinergic intervention as a result of OCR, and there were no postoperative ramifications of the OCR.
  
  
  CONCLUSIONS
  OCR occurs in nearly one-third of patients who undergo the OZ approach. However, simple cessation of orbital manipulation is sufficient to normalize the patient's heart rate. Rarely is medical management required or does there appear to be any significant postoperative ramifications.
authors.affiliation: Department of Neurosurgery, Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA. Electronic address: dmneils@yahoo.com.
authors.forename: David M
authors.initials: DM
authors.lastname: Neils
authors.affiliation: Department of Neurosurgery, Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA.
authors.forename: Pradeep S
authors.initials: PS
authors.lastname: Singanallur
authors.affiliation: Department of Neurosurgery, Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA.
authors.forename: Michail
authors.initials: M
authors.lastname: Vasilakis
authors.affiliation: Department of Medicine, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA.
authors.forename: Huaping
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Tsung
authors.affiliation: Department of Neurosurgery, Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klopfenstein
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003399:Craniotomy / Q000009:adverse effects; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D009915:Orbit / Q000601:surgery*; D011446:Prospective Studies; D012024:Reflex, Oculocardiac; D055815:Young Adult; D015050:Zygoma / Q000601:surgery*
keywords: Oculocardiac reflex; Orbital manipulation; Orbitozygomatic approach; Osteotomy