Cervical spine motion during airway management:: A cinefluoroscopic study of the posteriorly destabilized third cervical vertebrae in human cadavers

We conducted a randomized, controlled, crossover study to determine cervical spine motion for six airway management techniques in human cadavers with a posteriorly destabilized third cervical (C-3) vertebra. A destabilized C-3 segment was created in 10 cadavers (6-24 h postmortem). Cervical motion was recorded by continuous lateral fluoroscopy. The following airway management techniques were performed in random order on each cadaver with manual in-line stabilization applied: face mask ventilation (FM), laryngoscope-guided orotracheal intubation (OETT), fiberscope-guided nasal intubation (FOS-NETT), esophageal tracheal Combitube(R) (Kendall-Sheridan, Neustadt, Germany) insertion (ETC), intubating laryngeal mask insertion with fiberscope-guided tracheal intubation (ILM-OETT), and laryngeal mask airway insertion (LMA). Afterward, maximum head-neck flexion (FLEX-MAX) and maximum head-neck extension (EXT-MAX) without manual, in-line stabilization was performed to determine maximum motion. The maximum posterior displacement of C-3 and the maximum segmental sagittal motion of C2-3 were determined. There was a significant increase in posterior displacement for the FM (1.9 +/- 1.2 mm, P < 0.01), OETT (2.6 +/- 1.6 mm, P < 0.0001), ETC (3.2 +/- 1.6 mm, P < 0.0001), ILM-OETT (1.7 +/- 1.3 mm, P < 0.01), LMA (1.7 +/- 1.3 mm, P < 0.01), FLEX-MAX (3.7 +/- 1.9 mm, P < 0.0001), EXT-MAX (1.8 +/- 1.7, P ( 0.01), however, not for FOS-NETT (0.1 +/- 0.7 mm). Posterior displacement was less for the ILM-OETT and LMA than for the ETC (both P < 0.04). There were no significant increases in seg mental sagittal motion with any airway manipulation other than with FLEX-MAX(-4.5 +/- 4.0<degrees>, P < 0.01). Posterior displacement was similar to FLEX-MAX for the OETT and ETC; however, it was less for the FM, FOS-NETT, ILM-OETT, and LMA (all P < 0.01). Posterior displacement was similar to EXT-MAX for all airway manipulations other than for FOS-NETT (P < 0.001). For cervical motion and the techniques tested, the safest method of airway management in a patient with a posteriorly destabilized C-3 segment is FOS-NETT. LMA devices may be preferable to the ETC.