A comparison between left molar direct laryngoscopy and the use of a Bonfils intubation fibrescope for tracheal intubation in a simulated difficult airway.

BACKGROUND: Tracheal intubation in patients with an immobilized cervical spine can be difficult because of a restricted mouth opening and limited neck movements. Use of the Bonfils intubation fibrescope (BIF) or left molar (LM) laryngoscopy may be suitable options for tracheal intubation in such patients. Intubation adjuncts, such as an endotracheal tube introducer, may improve the overall intubation success rate with the LM approach. Formal studies are currently lacking on the use of LM laryngoscopy with a tube introducer.

METHODS: After Institutional Review Board approval, a cervical collar (to simulate a difficult airway scenario) was placed on 120 prospective elective surgical patients who were randomly assigned to tracheal intubation with a BIF (Group BIF, n = 60) or with tube introducer-assisted LM laryngoscopy with routine optimal external laryngeal manipulation (Group LM, n = 60). The groups were compared for the primary endpoint, total intubation time, as well as for time to glottic view, tube introducer insertion time, intubation success rate, number of intubation attempts, and airway complications.

RESULTS: The mean (SD) total time for intubation was longer in Group LM than in Group BIF [40.4 (14.2) sec vs 33.1 (15.4) sec, respectively; mean difference 7.3 sec; 99% confidence interval (CI) 3.2 to 14.4; P < 0.001] despite less mean (SD) total time required for glottic view [15.4 (10.3) sec vs 23.8 (15.7) sec, respectively; mean difference 8.3 sec; 99% CI 2.3 to 14.7; P < 0.001]. The overall success rate was comparable between groups (95.0% in Group BIF vs 96.6% in Group LM; P = 0.64). Tracheal intubations could not be performed as per protocol in three patients in Group BIF and in two patients in Group LM and were considered as failures. No differences between the groups were found in the incidence of side effects.

CONCLUSION: The tube introducer-assisted LM approach to intubation may be a good alternative to the BIF approach in patients with anticipated and unanticipated difficult airway scenarios.