A simulated severe difficult airway does not alter the intubation performance with the SensaScope: a prospective randomised manikin study

Abstract

DESIGN:

Prospective randomised controlled study.
SETTING:

Operation unit in a tertiary academic university hospital in a central European city. Period of the study was springtime and summer 2010.
PATIENTS OR OTHER PARTICIPANTS:

Twenty-four anaesthesiologists with various levels of professional experience were allocated to intubate an airway manikin either with the SensaScope (group S) or with the conventional Macintosh 3 laryngoscope (group L).
INTERVENTIONS:

Each participant performed three consecutive intubations with normal anatomy followed by three intubations with difficult anatomy. The airway difficulty was simulated by inflation of the manikin's tongue base with 40 ml of air. The times taken to view the larynx and to insert the tracheal tube were noted. The resulting tube position and the occurrence of dental damage were recorded.
MAIN OUTCOME MEASURES:

Those planned in the protocol.
RESULTS:

In normal anatomy, the laryngeal view (group L 5.9 ± 4.2 s vs. group S 9.2 ± 3.5 s) and intubation (group L 13.4 ± 7.6 s vs. group S 23.3 ± 8.6 s) was more rapidly obtained with conventional laryngoscopy (values presented as mean ± SD). In difficult anatomy, only the SensaScope permitted successful laryngeal view (group L impossible vs. group S 9.9 ± 4.8 s) and tracheal intubation (group L impossible vs. group S 23.4 ± 8.8 s). The latter always enabled correct tracheal tube position, whereas with laryngoscopy alone either oesophageal intubation or aborted attempts resulted. In the difficult airway setting, the frequency of simulated tooth damage was also significantly higher with conventional laryngoscopy (group L 26 of 36 vs. group S 6 of 36).
CONCLUSIONS:

The SensaScope performed fairly well in normal intubation anatomy, although its use was more complex than with conventional laryngoscopy and it required a slightly longer time. In the difficult airway setting, the SensaScope performed as well as in normal anatomy, whereas intubation by direct laryngoscopy proved to be impossible. The SensaScope enables the user to overcome severe airway difficulties caused by large tissue masses at the level of the tongue base or mouth floor.