Cervical Spine Motion During Airway Management Using Two Manual In-line Immobilization Techniques: A Human Simulator Model Study.

Objective: The aim of this study is to evaluate cervical spine motion using 2 manual inline immobilization techniques with the use of a human simulator model.

Methods: Medical students, pediatric and family practice residents, and pediatric emergency medicine fellows were recruited to maintain cervical manual in line immobilization above the head of the bed and across the chest of a human simulator while orotracheal intubation was performed. Participants were then instructed on appropriate holding techniques after the initial session took place. Orotracheal intubation followed. A tilt sensor measured time to intubation and cervical extension and rotation angle.

Results: Seventy-one subjects participated in a total of 284 successful orotracheal intubations. No change in cervical spine movement or time to intubation was observed when using 2 different inline manual immobilization techniques with no training. However, a statistically significant difference with assistants above the head versus across the chest was observed after training in: extension 2.1° (95% confidence interval [95% CI], 1.15 to 3.00; P < 0.0001); rotation 0.7° (95% CI, 0.26 to 1.19; P = 0.003) and intubation time of -1.9 seconds (95% CI, -3.45 to -0.13; P = 0.035) after training.

Conclusions: Cervical spine movement did not change when maintaining cervical spine immobilization from above the head versus across the chest before training. There was a statistically significant change in extension and rotation when assistants were above the head and in time to intubation when assistants were across the chest after training. The clinical significance of these results is unclear.