Awake video laryngoscopy

A nice study reminds of us the option of awake video laryngoscopy as an alternative to fibreoptic instrumentation of the airway. The study was done on healthy volunteers so we have no idea of the applicability to the patient group we would be interested in using this on – those with an anticipated difficult airway sufficiently stable to allow tolerance and preparation for this procedure. The videolaryngoscopy was performed with patients upright in a face-to-face position, with the laryngoscope inserted in the inverted handle-down (“tomahawk”) position (this is the way I remove fishbones using a direct laryngoscope and Magill’s forceps).
Visualization was faster with video laryngoscopy, and grade of view was similar in both groups. Cormack Lehane grading was used to assess view, whereas the POGO score (percentage of glottic opening) might have provided a better means of assessing which view is superior. The study did not evaluate endotracheal tube insertion.
Local anaesthesia was provided with 5 ml nebulised 4% lidocaine and weight-based doses of 4% lidocaine were then sprayed into the nose and oropharynx through a mucosal atomisation device to a maximum of 9 mg/kg. Oxymetazoline was applied nasally for the flexible fibreoptic laryngoscopy.

Study objectives: We compare laryngoscopic quality and time to highest-grade view between a face-to-face approach with the GlideScope and traditional flexible fiber-optic laryngoscopy in awake, upright volunteers.

Methods: This was a prospective, randomized, crossover study in which we performed awake laryngoscopy under local anesthesia on 23 healthy volunteers, using both a GlideScope video laryngoscopy face-to-face technique with the blade held upside down and flexible fiber-optic laryngoscopy. Operator reports of Cormack-Lehane laryngoscopic views and video-reviewed time to highest-grade view, as well as number of attempts, were recorded.

Results: Ten women and 13 men participated. A grade II or better view was obtained with GlideScope video laryngoscopy in 22 of 23 (95.6%) participants and in 23 of 23 (100%) participants with flexible fiber-optic laryngoscopy (relative risk GlideScope video laryngoscopy versus flexible fiber-optic laryngoscopy 0.96; 95% confidence interval 0.88 to 1.04). Median time to highest-grade view for GlideScope video laryngoscopy was 16 seconds (interquartile range 9 to 34) versus 51 seconds (interquartile range 35 to 96) for flexible fiber-optic laryngoscopy. A distribution of interindividual differences demonstrated that GlideScope video laryngoscopy was, on average, 39 seconds faster than flexible fiber-optic laryngoscopy (95% confidence interval 0.2 to 76.9 seconds).

Conclusion: GlideScope video laryngoscopy can be used to obtain a Cormack-Lehane grade II or better view in the majority of awake, healthy volunteers when an upright face-to-face approach is used and was slightly faster than traditional flexible fiber-optic laryngoscopy. However, flexible fiber-optic laryngoscopy may be more reliable
at obtaining high-grade views of the larynx. Awake, face-to-face GlideScope use may offer an alternative approach to the difficulty airway, particularly among providers uncomfortable with flexible fiber-optic laryngoscopy.

GlideScope Versus Flexible Fiber Optic for Awake Upright Laryngoscopy
Ann Emerg Med. 2012 Mar;59(3):159-64

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