key: cord-0684019-dg05126y
authors: Sandefur, Benjamin J.; Driver, Brian E.; Brown, Calvin A.; Reardon, Robert F.
title: Definitive Airway Management of Patients with a King Laryngeal Tube(™) in Place in the COVID-19 Pandemic
date: 2020-04-24
journal: West J Emerg Med
DOI: 10.5811/westjem.2020.4.47462
sha: fc77ba0f1f8f7bcd0a38fc2d4eb1870cc36eed9a
doc_id: 684019
cord_uid: dg05126y

nan

[West J Emerg Med. 2020;21(3)542-545.]

Disclaimer: Due to the rapidly evolving nature of this outbreak, and in the interests of rapid dissemination of reliable, actionable information, this paper went through expedited peer review. Additionally, information should be considered current only at the time of publication and may evolve as the science develops.

To the Editor,

The COVID-19 pandemic has generated enhanced focus on the safety of healthcare providers and efforts to mitigate the risks of viral transmission. 1 Reports of previous viral epidemics have described substantially increased risk to providers performing laryngoscopy and tracheal intubation in patients infected with the virus. 2, 3 Additionally, bronchoscopy and other endoscopic airway procedures are considered high-risk, aerosol-generating procedures. 1 The King LT(S)-D laryngeal tube (King Systems, Noblesville, IN), abbreviated hereafter as the King LT, is a new-generation extraglottic device (Figure 1 ) used as a primary or backup airway device by many emergency medical systems systems. This device has been demonstrated to have advantageous attributes as compared to other extraglottic airway devices, with favorable safety outcomes and high rates of successful insertion. [4] [5] [6] [7] However, the King LT is not a definitive airway device and is not intended for long-term use. Additionally, the King LT has been associated with post-insertion airway edema, which, in addition to risk factors inherent to the patient, may further impede subsequent laryngoscopy attempts. 8 9 However, this technique may increase generation of aerosols containing highly infectious viral particles. Additionally, many emergency physicians may be unfamiliar with this approach or lack the necessary endoscopic equipment. Given the current COVID-19 pandemic, emergency physicians need to have a straightforward, safe approach for definitive airway management in patients with a King-LT using airway equipment commonly found in the emergency department (ED).

In 2016, Dodd and colleagues introduced a novel, nonsurgical approach to facilitate definitive airway management in ED patients with a King LT in place. 10 The authors described use of a standard-geometry video laryngoscope and bougie to intubate the trachea with the King LT device remaining in situ. A bougie is used, instead of initial intubation with a tracheal tube, given its smaller diameter and the inherent space limitation that the King LT imposes within the pharynx where the devices are manipulated. Furthermore, the on-screen visualized supraglottic region might be obscured as the larger endotracheal tube passage is attempted, while use of a bougie results in less obstruction of the visualized field. The authors reported a 99.8% success rate with this nonsurgical and non-endoscopic technique, and noted that in rare cases of failed intubation, the King LT remains in a functional position allowing for balloon reinflation and resumption of ventilation. A subsequent, proof-of-concept cadaveric study demonstrated similar (100%) first-pass success, although the authors acknowledged the potential for overestimation given the small sample size. 11 This concept was demonstrated in real-world clinical practice in an observational study of 647 patients arriving to the ED with a prehospital-placed King LT. 12 In this study 112 of 647 patients underwent intubation with the King LT left in place, with the balloons deflated,

Airway Management of Patients with King-LT during COVID-19 Pandemic with first-attempt success in 102 (91%). Of the 10 patients with first-attempt failure, eight patients were intubated with the same technique on the second attempt; the remaining two were intubated with bougie facilitation after removing the King LT. We believe that the King LT exchange method described by Dodd and colleagues represents a safe and simple approach that can be readily performed by clinicians who are skilled at video laryngoscopy. Further, we believe that this method, used in combination with administration of a highdose, paralytic medication to mitigate spontaneous patient respiration and cough during the procedure, represents the safest method for both patients and care providers to exchange a King LT for a cuffed tracheal tube in a patient with known or suspected COVID-19. Lastly, the airway equipment required is readily available to most emergency providers, critical care providers, and anesthesiologists. We describe this procedure, with updates accounting for risks inherent to the COVID-19 pandemic, in Figures 2 and 3 . 1. Patient should be in a negative pressure room, if available 2. Lean team to minimize provider exposure 3. Strictly adhere to enhanced respiratory PPE donning protocol with observer 4. Most experienced clinician intubates 5. Ensure a viral filter is attached to King LT 6. Immediately check pilot balloon and, if needed, adjust balloon pressure to prevent air leak 7. Ensure preoxygenation for 5 minutes with 100% FiO 2 via the existing King LT 8. Ensure appropriate sedation and administer high-dose NMBA, if not already given 9. Wait appropriate amount of time for paralytic onset (45-60 seconds) 10 . Suspend ventilator at end-expiration, prior to video laryngoscope insertion or King LT manipulation, to minimize risk of air leak and aerosol-generation 11. Insert a standard geometry video laryngoscope into the mouth, between the tongue and inflated oropharyngeal balloon, advancing toward the vallecula until the balloon fills the VL screen 12. Completely deflate the King LT balloons, leaving the King LT in place 13. Manipulate the video laryngoscope to identify and engage the vallecula, visualizing arytenoid cartilages and vocal cords 14. Pass a bougie (or equivalent) into the oropharynx and indirectly visualize passage into the trachea, achieving further confirmation with feeling the tracheal rings 15. Advance a tracheal tube over the bougie, utilizing a 90-degree counterclockwise rotation to pass the arytenoid cartilages, and visualize passage into the trachea 16. Immediately inflate the tracheal tube cuff, withdraw the bougie, and attach a viral filter 17. Attach the closed-circuit ventilator, begin ventilation, and confirm tracheal tube placement with end tidal continuous capnography and chest rise (*do not use bag ventilation to check placement, in order to limit ventilator circuit disconnects) 18. Carefully withdraw the deflated King LT, maintaining indirect visual confirmation of tracheal tube placement 19. Withdraw the video laryngoscope and secure the tracheal tube 20. Strictly adhere to PPE doffing protocol with observer and perform hand hygiene 

Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected. Interim Guidance

Risk Factors for SARS Transmission from Patients Requiring Intubation: A Multicentre Investigation in Toronto

Aerosol Generating Procedures and Risk of Transmission of Acute Respiratory Infections to Healthcare Workers: A Systematic Review

A comparison of the King-LT to endotracheal intubation and Combitube in a simulated difficult airway

Airway Management of Patients with King-LT during COVID-19 Pandemic

The King LT versus the Combitube: flight crew performance and preference

Out-of-hospital airway management by paramedics and emergency physicians using laryngeal tubes

A pilot study of the King LT supralaryngeal airway use in a rural Iowa EMS system

Tongue engorgement associated with prolonged use of the King-LT laryngeal tube device

Definitive airway management of patients presenting with a pre-hospital inserted King LT(S)-DTM laryngeal tube airway: a historical cohort study

Definitive airway man-agement in emergency department patients with a King laryngeal tube in place: a simple and safe approach

Endotracheal intubation with the King laryngeal tube in situ using video laryngoscopy and a bougie: a retrospective case series and cadaveric crossover study

Emergency Department Management of Out-of-Hospital Laryngeal Tubes