Disposable laryngeal tube suction: standard insertion technique versus two modified insertion techniques for patients with a simulated difficult airway

Objective: The disposable laryngeal tube suction (LTS-D) is a supraglottic airway device that can be used as an alternative to tracheal tube to provide ventilation. We tested the hypothesis that, with a frontal jaw thrust insertion technique (FIT/JT), the rate of correct placement attempts in patients with a simulated difficult airway by means of a rigid cervical immobilization collar could be significantly increased compared to the standard insertion technique (SIT) recommended by the manufacturer.

Methods: 70 adult patients undergoing trauma surgery under general anaesthesia had an LTS-D inserted, randomly assigned to the SIT or FIT/JT. In the FIT/JT, the operator was standing in front of the patient's head, and forced chin lift to create sufficient retropharyngeal space was performed. The rate of successful tube placements within 180s and with a maximum of two attempts was the main outcome variable. To distinguish between the effects of the frontal approach and the jaw thrust manoeuvre, a third group was studied after completion of the SIT and FIT/JT groups. The standard insertion technique, but with a jaw thrust manoeuvre (SIT/JT), was employed in another 35 consecutive patients.

Results: Overall placement success was 49% (SIT, 17/35 patients, P<0.001), 91% (SIT/JT, 32/35 patients) and 100% (FIT/JT). The time required for successful insertion was shortest in the FIT/JT group (23±6s), and significantly longer in the SIT/JT (42±29s, P<0.001) and SIT groups (51±29s, P<0.0001).

Conclusion: In anaesthetised patients with a simulated difficult airway created with a rigid cervical collar, the overall LTS-D placement success was significantly higher when a jaw thrust manoeuvre was performed, regardless of the particular technique used to introduce the LTS-D. Therefore, an intense jaw thrust manoeuvre should be performed whenever an LTS-D is being inserted.