Cervical spinal motion during intubation: efficacy of stabilization maneuvers in the setting of complete segmental instability

Object. The purpose of this study was to characterize and compare segmental cervical motion during orotracheal intubation in cadavers with and without a complete subaxial injury, as well as to examine the efficacy of commonly used stabilization techniques in limiting that motion. Methods. Intubation procedures were performed in 10 fresh human cadavers in which cervical spines were intact and following the creation of a complete C4-5 ligamentous injury. Movement of the cervical spine during direct laryngoscopy and intubation was recorded using video fluoroscopy and examined under the following conditions: 1) without stabilization; 2) with manual in-line cervical immobilization: and 3) with Gardner-Wells traction. Subsequently, segmental angular rotation, subluxation, and distraction at the injured C4-5 level were measured from digitized frames of the recorded video fluoroscopy. Conclusions: After complete C4-5 destabilization, the effects of attempted stabilization on distraction, angulation, and subluxarion were analyzed. Immobilization effectively eliminated distraction, and diminished angulation, but increased subluxation. Traction significantly increased distraction, but decreased angular rotation and effectively eliminated subluxation. Orotracheal intubation without stabilization had intermediate results, causing less distraction than traction, less subluxation than immobilization, but increased angulation compared with either intervention. These results are discussed in terms of both statistical and clinical significance and recommendations are made.