The combination of a fiberoptic stylet and a McCoy laryngoscope facilitates tracheal intubation in difficult airway cases

Video-Twin Technique for Airway Management, Combining Video-Intubating Stylet with Videolaryngoscope: A Case Series Report and Review of the Literature

Direct laryngoscopy (DL) and videolaryngoscopy (VL) have been the most commonly used airway management modalities in the last several decades. Meanwhile, various optional airway tools (e.g., supraglottic devices, fiberoptic bronchoscopes) have been used for alternative rescue modalities when anticipated or unexpected difficulties in airway management has occurred. In recent decades, optical stylets and video-assisted intubating stylets have become another option for difficult airway scenarios. In contrast to other approaches, we have adopted the Shikani video-assisted intubating stylet technique (VS) for both routine and difficult airway management scenarios. In this case series report, we present the video-twin technique, combining a videolaryngoscope with a video-assisted intubating stylet in various clinical case scenarios. We propose that such a combination is easy to learn and employ and is particularly beneficial in situations where an expected difficult airway (EDA) is encountered.

A Comparison of a Fiberoptic Stylet and a Bougie as Adjuncts to Direct Laryngoscopy in a Manikin-Simulated Difficult Airway

STUDY OBJECTIVE

We compare the effectiveness of an endotracheal tube introducer ("bougie") with a new fiberoptic stylet as an adjunct to direct laryngoscopy in facilitating simulated difficult tracheal intubation in a manikin.

METHODS

Inexperienced laryngoscopists were recruited for this randomized, crossover study. After brief training, participants were randomized to first use either the bougie or fiberoptic stylet as an adjunct to direct laryngoscopy for attempted tracheal intubation of a manikin presenting a fixed, simulated, Cormack-Lehane grade IIIA view. Two attempts at tracheal intubation were allowed, each limited to 60 seconds. The participant then crossed over and used the other device. The same procedure was then repeated on a second manikin presenting a simulated Cormack-Lehane grade IIIB view. Primary outcomes were time to tracheal intubation and successful endotracheal tube placement.

RESULTS

One hundred three study participants performed a total of 533 tracheal intubations for evaluation. For the Cormack-Lehane grade IIIA view, correct placement of the endotracheal tube was achieved in 101 (98%) of the fiberoptic stylet-facilitated and all 103 (100%) of the bougie-facilitated tracheal intubations. The time to successful tracheal intubation was similar for both devices (difference in mean time 1.8 seconds; 95% confidence interval [CI] -2.5 to 6.1 seconds). In the Cormack-Lehane grade IIIB view manikin, use of the fiberoptic stylet significantly increased success rate (fiberoptic stylet 98% versus bougie 9%), and a trend was observed toward a decrease in the mean time required for successful tracheal intubation compared to the bougie (fiberoptic stylet 31.0 seconds versus bougie 45.6 seconds; difference in mean time -14.6 seconds; 95% CI -31.4 to 2.3 seconds).

CONCLUSION

In a manikin model, with inexperienced clinicians, both the bougie and the fiberoptic stylet were effective in facilitating tracheal intubation of a simulated Cormack-Lehane grade IIIA view. For a Cormack-Lehane IIIB view, the fiberoptic stylet was significantly more effective than the bougie in facilitating tracheal intubation. Because a manikin model eliminates some of the barriers to use of fiberoptics in patients, further validation of fiberoptic stylet use is required in human subjects with normal and difficult airways.

Tracheal intubation using the ILMA, C-TrachTM or McCoy laryngoscope in patients with simulated cervical spine injury

A study of 90 patients was undertaken to compare intubation success rates of using either ILMA, C-Trach or McCoy laryngoscope in patients with simulated cervical spine injury. Insertion and intubation success rates, time taken to achieve intubation, airway complications and haemodynamic parameters were recorded. Insertion of ILMA and C-Trach was successful at the first attempt in all patients. Intubation success rates were higher in the C-Trach (100%) and McCoy (100%) groups than in the ILMA (87%) group. Total intubation time was significantly longer in the ILMA (63 s, SD 36.5) group than in the C-Trach (41 s, SD 15.8) and McCoy (30 s, SD 7.4) groups (p < 0.05, p < 0.05, respectively). There were no significant differences in haemodynamic parameters among the groups at any time.