Question 19

A 73-year-old patient with a history of ankylosing spondylitis and type 2 diabetes presents with severe respiratory failure.

You are asked to review the patient in the Emergency Department as there has been progressive deterioration since presentation. The patient is clearly dyspnoeic with a respiratory rate of 35 breaths/min and oxygen saturation of 86% on supplemental oxygen of 15 L/min through a non-rebreather mask. A decision has been made to progress to urgent intubation.

Discuss potential difficulties or challenges you foresee and your strategies for dealing with them under the following headings.

a)    Infection control measures during the airway procedure.    (20% marks)

b)    Securing the airway.    (80% marks)
 

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College answer

Not available.

Discussion

The first two marks of this question are dedicated to a topic which, during the COVID pandemic, had a remarkable amount of ink spilled over it. Trainees may recall how countless airway management policies were hastily drafted and revised to minimise staff exposure to aerosols, draping the patient in various plastic sheets, clamping tubes and performing checklist rituals. This "infection control measures during the airway procedure" section expects those same trainees to purify the last two years of confusing and rapidly mutating guidelines into some kind of point-form condensate, for under fifty words.

The best resource for this that probably crosses the most international boundaries is the NEJM video from 2021 by Shrestha et al. To narrow things even more, for COVID patients with difficult airways, this 2021 set of guidelines from the Society of Airway Management spells out all the issues that need to be considered. The reader is warned that these are not standard guidelines by any means, i.e the recommendations they make may not be endorsed by every jurisdiction around the world, and every airway expert is likely to have their own  opinion on this situation. As the result, the possible range of answers to this question is quite broad, and what follows should be viewed as a guide or suggestion for how to approach this SAQ rather than any sort of model answer

Infection control measures

  • Potential difficulties:
    • The patient may have COVID, which places staff at risk of exposure
    • The intubation is likely to be difficult, meaning that it will likely take longer, require more staff and equipment, and involve more aerosol-generating procedures
  • Solution:
    • Move the patient into a single-bed negative pressure room
    • Minimise staff in the room (four should be enough), bring only essential equipment
    • PPE for all staff (N95, hat, goggles, face shield, gloves, gown)
    • No bag-valve-mask ventilation after relaxant
    • And/or: viral filter on the BVM apparatus
    • Clamp ETT following intubation, unclamp when connected to the ventilator

Preparation for intubation

  • Potential difficulties:
    • Severe respiratory failure, with minimal margin for error and a considerable potential for profound hypoxia during intubation
    • Potentially a difficult airway given the history of ankylosing spondylitis
  • Management of respiratory failure:
    • Maximise periprocedural oxygenation:
      • Well-sealed face mask with viral filter and EtCO2 module
      • Preoxygenation on NIV and apnoeic oxygenation with HFNP is an alternative, but thought to be the inferior option and is not routinely recommended
  • Management of the airway:
    • Assess the airway, anticipating problems with neck extension
      • Determine whether bag-valve-mask ventilation is also likely to be difficult
    • Consider options
      • Awake fibreoptic intubation would be ideal, but is a highly aerosol-generating procedure, and should be avoided if possible
      • Videolaryngoscopy with alternative curved blade and tube over flexible metal stylette
    • Prepare the patient
      • Brief patient regarding the need for intubation
      • Explain the steps which you will take
    • Prepare personnel
      • Help from the most senior airway technician should be sought, in addition to standard personnel for drugs, airway assistance, etc
      • A non-PPE runner should be available to fetch equipment, waiting outside the negative pressure room
    • Prepare equipment
      • Standard intubation equipment
      • difficult airway trolley (LMA, including intubating LMA)
      • equipment for emergency surgical airway
      • resuscitation equipment
    • Prepare the scenario
      • Go through the checklist of equipment
      • Discuss the plans (A, B and C) with all the staff
      • Example plans:
        • Plan A: rapid sequence induction and videolaryngoscopy with "D" blade CMAC or similar
        • Plan B: intubating LMA
        • Plan C: 
        • Emergency rescue: scalpel-bougie-tube

References

Shrestha, Gentle Sunder, et al. "Emergency Intubation in Covid-19." The New England Journal of Medicine 384.7 (2021): e20-e20.

Apfelbaum, Jeffrey L., et al. "Practice Guidelines for Management of the Difficult Airway An Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway." The Journal of the American Society of Anesthesiologists 118.2 (2013): 251-270.

Foley, Lorraine J., et al. "Difficult airway management in adult coronavirus disease 2019 patients: statement by the Society of Airway Management." Anesthesia & Analgesia 133.4 (2021): 876-890.