title: Cervical spine overflexion in a halo orthosis contributes to complete upper airway obstruction during awake bronchoscopic intubation: a case report.
abstract: OBJECTIVE
  We present a case of upper airway obstruction in a patient with an unstable cervical spine fracture in a halo orthosis. We also describe the mechanism by which the obstruction occurred and identify features that predispose patients in a halo orthosis to upper airway obstruction.
  
  
  METHODS
  An 81-yr-old female presenting to hospital with an unstable cervical spine fracture was scheduled for spinal fusion. She was fitted with a halo traction device in a flexed position, and an awake tracheal intubation was planned. The patient's airway was topicalized and 1 mg of midazolam was administered. Her oxygen saturation dropped, and mask ventilation was difficult and insufficient. She then became unresponsive and pulseless. Emergency release of the halo orthosis device was carried out and her neck was held in a neutral position. Mask ventilation was successfully performed and oxygenation improved. The patient's trachea was intubated via video laryngoscopy, and she was resuscitated and taken to the intensive care unit. The degree of cervical spine flexion resulting from the halo fixation was examined in subsequent radiographs, as defined by the occiput to C2 (O-C2) angle, and the oropharyngeal cross-sectional area was measured. Spine flexion from halo fixation in concert with the topical treatment and sedation predisposed the patient to acute airway obstruction.
  
  
  CONCLUSIONS
  In this case, external cervical spine fixation in flexion resulted in a change to the O-C2 angle, which reduced the oropharyngeal area and predisposed to upper airway obstruction. This highlights the need for anesthesiologists to evaluate the degree of cervical spine flexion in patients with halo devices and to have the surgical team present during airway management in the event of acute airway obstruction.
authors.affiliation: Department of Anesthesia and Toronto Western Hospital Spine Program, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Alexander N J
authors.initials: AN
authors.lastname: White
authors.forename: David T
authors.initials: DT
authors.lastname: Wong
authors.forename: Christina L
authors.initials: CL
authors.lastname: Goldstein
authors.forename: Jean
authors.initials: J
authors.lastname: Wong
mesh_terms: D000369:Aged, 80 and over; D000402:Airway Obstruction / Q000209:etiology* / Q000628:therapy*; D001999:Bronchoscopy; D002574:Cervical Vertebrae / Q000293:injuries*; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D009989:Orthotic Devices / Q000009:adverse effects*; D012151:Resuscitation; D016103:Spinal Fractures; D014851:Wakefulness