ATLANTOAXIAL subluxation (AAS) is found in 11-46% of patients with rheumatoid arthritis. 1 Rheumatoid patients with AAS may be at risk of life-threatening neurologic injury caused by exacerbation of the subluxation in the head and neck position during airway maneuver; therefore, appropriate management of the cervical spine is essential. [2][3][4][5] Tokunaga et al. 6 have recommended the protrusion position, which is equal to the posture used in anesthesiology as the sniffing position, during intubation attempt in these patients to reduce subluxation. In contrast, previous studies have shown that accomplishment of the protrusion position sometimes results in worsening AAS in rheumatoid patients with severe instability of the occipitoatlantoaxial (OAA) complex. 7,8 In cases of severe OAA instability, appropriate head and neck position during airway maneuver is poorly understood despite its importance. Minimizing movement of the cervical spine may be the only method for avoiding exacerbation of AAS and protecting the spinal cord.It is often difficult to predict the degree of cervical spine motion for laryngoscopy and intubation because the motion varies from individual to individual. 9 Moreover, prediction is all the more difficult in patients with rheumatoid arthritis because their trachea is sometimes difficult to intubate. 10 These indicate that, despite the necessity of minimizing cervical movement, the degree of the motion is not known until laryngoscopy and intubation are performed. Observation of the cervical motion during airway maneuver may provide a safer management. We report a case of fluoroscopic observation of the OAA complex during laryngoscopy and intubation in a rheumatoid patient with severe AAS.
Case ReportA 66-yr-old, 160-cm, 43-kg woman was scheduled to undergo surgical repair of a fractured femur. She was known to have an unstable cervical spine because of rheumatoid arthritis, which had been described in our previous report. 8 Airway examination consisted of Mallampati Class 2 with a mouth opening of 4 cm and hyomental distance ratio of 1.31. 11 The patient could move her head and neck without limitation, but preoperative assessment of the cervical spine with lateral cervical spine radiography in flexion and extension provided evidence of instability at the OAA complex. The atlas-dens intervals (ADI) in flexion and extension were 10 mm and 2 mm, respectively. The ADI was defined as the distance between the posterior surface of the anterior arch of the atlas and the anterior surface of the dens. 1,8 We counseled general anesthesia with awake fiberoptic intubation or regional anesthesia because her previous operations had been safely performed under these anesthetic techniques. Nevertheless, the patient refused them because of the stress she had experienced on previous operations. Combination of the Airway Scope (AWS, AWS-S100; HOYA-Pentax, Tokyo, Japan) and the bougie (Portex Venn reusable endotracheal tube introducer; Smith Medical, Keene, United Kingdom) can minimize the cervical spine motio...