Airway technology has advanced rapidly in recent years and many emergency departments (EDs) now stock video laryngoscopes with hot-swappable disposable blades, second-generation laryngeal masks that are easier to place and designed to transmit an endotracheal tube, and single-use flexible endoscopes that bring the capabilities of conventional fiber-optic bronchoscopes to emergency settings. These advances introduce novel airway management options that are not yet widely utilized.¹ One particularly powerful example is the use of a flexible endoscope to facilitate tube delivery after the larynx has been exposed using a video laryngoscope. We call this video-assisted flexible endoscopic intubation VAFEI, pronounced “vaffy.”

The VAFEI Procedure

Preparation

• Preoxygenate and hemodynamically optimize the patient as time and physiology allow.
• If fully awake approach is undertaken, patient should be pretreated with antisialagogue and diligent topicalization of local anesthesia.
• Equipment list:
  • Intubating flexible endoscope (FE) preloaded with endotracheal tube
  • Video laryngoscope (VL) blade (hyperangulated geometry particularly advantageous but standard-geometry blade also effective)
  • Topical anesthetics (e.g., four percent lidocaine via atomizer) if non-paralyzed approach
  • Usual intubation and difficult airway equipment (e.g., suction, capnography, supraglottic device, cricothyrotomy materials)
• Positioning (Figure 1):
  • VL operator stands at the head of the bed behind the patient’s left shoulder.
  • FE operator stands at the head of the bed behind the patient’s head.
  • Patient should be positioned in semifowler position.
  • Screens (single split-screen is ideal) positioned over the patient’s bed in front of operators.

Airway Pharmacology

• If rapid sequence intubation (RSI) is undertaken, simultaneously administer sedative and paralytic agent.
• If non-paralyzed ketamine-only approach is undertaken, administer dissociative dose or titrated sub-dissociative doses of ketamine until patient is adequately induced.
• Application of atomized lidocaine to the larynx blunts cough and gag reflexes and reduces the chance of vocal cord spasm during ketamine-only approaches.
• When induced, VL operator performs laryngoscopy as usual to obtain adequate view (or, if difficult anatomy prevents adequate view, obtain best possible view). The VL operator, maintaining laryngoscope position with left hand, readies suction in right hand, in preparation for flexible endoscopy.
• Once VL operator obtains their view, the FE operator looks into the mouth, places the scope in the patient’s mouth, and advances to the end of the blade under direct visualization. The FE operator looks at the VL screen to guide the FE to the vocal cords.
• If performing an awake/breathing intubation, vocal cords may be anesthetized with four percent lidocaine via the utility port on the bronchoscope or using a mucosal atomization device.
• The FE operator then advances the FE through the cords, either under guidance of the VL screen or, if VL screen view is inadequate, using the FE screen (see Video 1 and Video 2 on our website).
• The FE operator advances the scope beyond the vocal cords until the carina is visualized.
• The FE operator or assistant railroads the preloaded endotracheal tube (ETT) beyond the vocal cords until the tip is seen on the FE screen.
• The FE operator withdraws the scope, visualizing the tip of the ETT just proximal to the carina to confirm proper positioning.
• The ETT is then attached to a bag valve mask (BVM) or ventilator circuit with waveform capnography to confirm gas exchange.

Pearls and Pitfalls

VAFEI is a simple procedure that can become complex if rushed. The right speed is slower than one’s instincts. Use suction liberally. If the airway is soiled, the VL operator must assertively suction fluids.

Preload the endotracheal tube with the tube’s natural curvature in the conventional orientation, with the bevel facing to the left.

Contemporary VL and FE scopes are heated to reduce the likelihood of fogging, but fogging may still occur and is improved by the use of defogging ointment, if available. Alternatively, if fogging of the endoscope occurs, gently press the tip of the scope against the patient’s mucosa to defog. If obstructive anatomy impedes advancing the flexible endoscope, the ETT itself can be used as a conduit; i.e., advance the tube beyond the FE until passage is clear to cords, then advance the scope through the tube and then through the cords. When advancing the tube, if there is a hold-up at the arytenoids, withdraw the tube slightly, then rotate the tube counterclockwise as you advance (left at the larynx, right at the rings for hold-up).² The VL must be held in place for the entire FE procedure, including as the ETT is railroaded over the scope. Maintaining VL position distracts obstructive tissues and allows visual confirmation of procedural steps.

A convenience sample of 10 patients intubated using the VAFEI technique is described in Table 1.

Click to enlarge Table 1.

Discussion

VAFEI has been described in operating room-based literature, including a randomized controlled trial that demonstrated benefit versus usual video laryngoscopy across a series of outcomes.^3,4,5 An emergency department-based case report described the technique with a channeled video laryngoscope, but it has received little attention as an intubation strategy in emergency medicine.⁶ VAFEI takes advantage of the strengths of each modality to address the weaknesses of the other. Though any blade shape can be used, VAFEI is particularly well-suited for use with hyper-angulated VL (HAVL), as steeply curved blades provide an optimal view of the glottis, but intubation failures and delays with HAVL are often attributable to difficulty maneuvering a styletted ETT to the glottis and then through the cords, down the trachea.^7-10 The flexible endoscope overcomes tube delivery difficulties commonly encountered during HAVL as the operator “drives” the scope around the primary and secondary airway curves that confound immobile stylets.¹¹

The use of a video laryngoscope facilitates flexible endoscopy and addresses key barriers to the use of FE in emergency settings. Most importantly, the laryngoscope clears a path through the mouth for the endoscope, allowing it to be manually inserted to the glottic inlet. This obviates the need to navigate the nose and nasopharynx, and reduces the difficulty in steering around the tongue and other oral structures. From an operator skills perspective, VAFEI can be likened to a bougie technique rather than a conventional flexible endoscopic intubation technique.

Unlike traditional awake flexible endoscopy, VAFEI can be performed very rapidly, which allows the procedure to be incorporated into an RSI-based paralyzed approach. RSI maximizes the likelihood of first pass success and for decades has been used in the majority of emergency department intubations.^12,13,14,15

VAFEI can be used as part of a topically anesthetized awake approach, however achieving sufficient local anesthesia that an awake patient will tolerate laryngoscopy requires more time than is available in many emergency intubation cases and is enabled by specialized equipment (e.g., atomizers, concentrated lidocaine) that may not be available.

VAFEI can also be incorporated into a ketamine-only strategy that attempts to take advantage of the safety benefit of ATI by maintaining spontaneous respirations while overcoming the challenges in executing effective topicalization, by using enough ketamine that the patient will tolerate laryngoscopy and tracheal intubation.¹⁶ The use of atomized lidocaine about the posterior oropharynx and glottis is still recommended, if feasible, to attenuate airway reflexes and laryngospasm that may impede tube delivery even in dissociated patients.

The primary drawback of the VAFEI technique is that it requires two operators: one to perform video laryngoscopy and one to advance the flexible endoscope. However, both operators need not be physicians, and in fact one operator can perform VAFEI by first completing laryngoscopy and then handing off the VL to an assistant positioned to the operator’s left, behind the patient. VAFEI requires that both VL and FE devices be available and ready, which is a barrier in many departments; however, the emergence of single-use, disposable VL blades and endoscopes allows wider adoption of this technology in emergency settings. Operation of the flexible endoscope in VAFEI does not require the same degree of skill as is needed to perform conventional flexible endoscopic intubation, but does require familiarity with the device and its basic functions, which can easily be acquired in a simulation training session.

Conclusion

VAFEI is a powerful intubation technique that takes advantage of the strengths of video laryngoscopy and flexible endoscopy while diminishing their drawbacks.¹⁷ It can be incorporated into approaches that preserve spontaneous ventilation and performed quickly enough to be used with paralysis and rapid sequence intubation. Because most anatomically difficult airways are unpredicted, it is essential that airway management strategies plan for first-attempt failure.^18,19,20

Dr. Strayer is an emergency physician at Maimonides Medical Center, in Brooklyn.

Dr. Caputo is associate chief of the Department of Emergency Medicine at NYC H+H/Lincoln Medical Center in the South Bronx.

References

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