Addendum 12/17/19 10:37AM
After reading feedback others have written on this NEJM article, it is important for you, the reader, to consider some of the concerns that have been raised. See Another Spoonful below. Personally, I found the article to have some helpful aspects and good anatomical drawings for my own review of airway anatomy, but I found that some of the discussion on treatment of croup seemed incorrect. Turns out, Drs. Farkas and Weingart raised some even more important issues. Please read critically and make sure you understand these different points of view.
Written by Clay Smith
This is a helpful review of upper airway obstruction. This is core knowledge that we need to refresh; the news is highlighted.
Why does the matter?
We are often the ones who deal with acute upper airway obstruction. We need to make sure our knowledge and skills in this area are current.
Air in and out, blood round and round
The upper airway consists of oropharynx and larynx.
Obstruction may occur at three levels: supraglottic, glottic, or subglottic.
Airway exam prior to intubation should incorporate several modes of assessment, such as Mallampati, weight, neck mobility, jaw mobility, retrognathia, prominent incisors, hyomental, and thyromental distance. One of the best methods is the upper lip bite test.
Causes and Treatment
Croup – racemic epinephrine is effective but temporary; oral dexamethasone 0.6mg/kg is key. Authors mention inhaled dexamethasone 160mcg in 3mL nebulized as first-line and nebulized epinephrine as an adjunct. That seems wrong and doesn’t fit with my experience over the past 20 years.
Supraglottitis, epiglottitis, or neck abscess – airway protection and antibiotics are top priorities. Elevated inflammatory markers and hyperglycemia are common. Vaccination has drastically decreased epiglottitis cases in children.
Ludwig’s angina – key actions are airway protection (preferably in the OR – ready to cric or trach), incision and drainage, and antibiotics. I&D vs antibiotics alone is 10-fold better.
Angioedema – ecallantide (a kallikrein inhibitor) or icatibant (a bradykinin receptor antagonist) may be used for hereditary cases. In cases with tongue or laryngeal swelling, drooling or stridor, intubation is more likely and should be fiberoptic if possible.
Tumor or foreign body – managed surgically
Glottic/Subglottic – most cases require surgical management. Psychogenic or vocal fold motion disorder requires retraining with speech/language pathology. Burns or trauma could affect any part of the airway.
Difficult Airway Algorithm
They propose the following:
Game changers in airway management have been the advent of super high-flow nasal cannula for preoxygenation and expanding use of video laryngoscopes. VL has improved first-pass success. Suggammadex (4mg/kg) has been FDA approved for reversal of vecuronium or rocuronium [However, this is rarely an option in emergency intubations for airway protection or respiratory failure. I added this as an addendum to the original post]. We all need to rehearse and do simulation to remain facile with cricothyrotomy. If experienced personnel are present, a true tracheostomy is preferred per this review article author. [This is debatable (also added as an addendum to the original post).]
Josh Farkas’ Twitter rantorial on this article is a MUST READ. He raises some serious concerns about this article.
And EMCrit posted a podcast to discuss this in more depth.
Thanks to Scott for pointing out these resources. I had not seen them prior to publishing the original post.
Acute Upper Airway Obstruction. N Engl J Med. 2019 Nov 14;381(20):1940-1949. doi: 10.1056/NEJMra1811697.
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