The effect of laryngoscopy of different cervical spine immobilisation techniques

Fifty patients underwent laryngoscopy with two different cervical spine immobilisation techniques. First the cervical spine was immobilised in a rigid collar with tape across the forehead and sandbags on either side of the neck, then with an assistant providing manual in-line immobilisation. Finally, patients underwent laryngoscopy in the routine intubating position. In 56% of patients the view of the larynx improved by one grade and in 10% the view improved by two grades when manual immobilisation was substituted for the collar, tape and sandbags (p < 0.0001). There was a poor view on laryngoscopy (grade 3 or 4) in 64% of patients when immobilised in a collar, tape and sandbags compared to 22% of patients undergoing in-line manual immobilisation (p < 0.001). Mouth opening was significantly reduced when patients were wearing cervical collars and this was the main factor contributing to the increased difficulty of laryngoscopy in this particular form of cervical spine immobilisation. It is recommended that manual in-line immobilisation should be the method of choice for cervical spine stabilisation during tracheal intubation.