Awake VDL Intubation With Dexmedetomidine, a Case Series (DexAwake)

Early after the videolaryngoscope'(VDL) introduction in clinical practice, the awake videolaryngoscopic (A-VDL) intubation took place with and instead of the awake video-bronchoscopic (A- VBS) intubation. The awake intubation is a safe profile technique that was underused since the only instrumentation available was the fiberoptic bronchoscope (FOB) or more recently the video-bronchoscope (VBS). With the VDL diffusion, the awake intubation option has eventually turned into a more utilized procedure, with the potential to become a daily procedure. This was also due to dexmedetomidine (DEX) introduction in The Operating Room pharmacopeia.

The emergency use of rescue techniques after failed intubation throws the operator into the rare, but unwanted emergency "Front of Neck Access" (FONA) scenario, while a failed awake intubation brings (carry, get) the operator into the "patient not intubated but safely and spontaneously breathing" scenario, moving away from the events of hypoxic complications and death.

Several steps must be standardized in order to homogeneously apply an awake intubation protocol. First, the patients need to be clinically evaluated for difficult intubation predictors. Most of the articles about prediction only investigated the relationship between difficult intubation' predictors and direct laryngoscopy and they showed poor to moderate sensitivity and specificity (Toshiga Shiga, Vannucci) but, moving on VDL' world this relationship has changed as showed by Cortellazzi et al with an AUC for El Ganzouri Risk Index improving from 0.74 to 0.9 using DL and Glidescope respectively. In addition to these considerations, all the most recent Airway Management Guidelines has confirmed as unmissable the clinical evaluation of anthropometric and clinical DI predictors. (DAS) Along with measuring all the EGRI parameters, it is pivotal to examine any abnormality in the head, pharyngo-laryngeal, neck, spine, and abdominal anatomy. Previous neck irradiation, mass lesions, neck circumference, super-obesity, severe cervico-dorsal kyphosis, or past pharyngo-laryngeal surgery have to be considered and may not alter the EGRI score that is, incidentally, made -as the other predictors -for apparently normal patients (Shiga).

A department protocol is recommended (awake intubation guidelines) but a low threshold for enrollment can be used to shorten and standardize the execution times.

We retrospectively evaluated 24 patients (from January 2019 to June 2021). For descriptive purposes, there are five procedural "Times": T0, T1, T2, T3, T4 and T5. T 0 is the start of the dexmedetomidine charge dose and local oral-pharyngeal anesthetic. In T1, the GAG reflex check is performed. In T2 fentanyl or ketamine is delivered. In T3 the local anesthetic is nebulized on vocal cord and trachea, under videolaryngoscopic view. T4 is the tube passage through the vocal cords. T5 is the EtCo2 curve assessment. At the end outcomes were measured.

Inclusion criteria

• Abnormality in the head, pharyngo-laryngeal, neck, spinal anatomy, super-obesity, El Ganzouri Risk Index > 6 or high risk for ab ingestis or hemorrhage (i.e.: tongue, pharynx-hypopharynx cancer lesions or arteriovenous malformations)

Exclusion criteria

• Interdental distance <1 cm
• Need for emergency airway stabilization.