The paediatric airway is for some reason a favourite of the college. Of the twenty-something paediatric SAQs in the last 16 years of the general CICM Part II, seven questions(i.e. around 33%) were about some aspect of airway management. This places the topic of the paediatric airway high on the list of revision priorities for the time-poor exam candidate in advanced stages of cram bloat. This chapter hopefully allows for rapid revision without digressing into useless fluff.
The following past paper SAQs have asked for details about the paediatric airway:
These were all similar enough that basically the same discussion section could be successfully cut-and-pasted across all of them.
The best published references for this topic are probably the belowmentioned articles by Holm-Knudsen et al (2009) and Cardwell et al (2003). Oh's chapter on the topic of airway obstruction (Ch 104, p.1077 of the 7th edition) is also a fun read, but is mainly concerned with discussing the various aetiologies of upper airway obstruction, on which several pages are spent. Relevant management information is literally left until the last half-page, making it an ineffective revision resource.
Broadly, the problems with the paediatric airway can be summarised in a table, which is a good format for answering questions like Question 5 from the second paper of 2014. There, the college wanted not only a list of anatomical features but "strategies that may be used to overcome these", and then complained that "candidates did not read the question thoroughly and did not include strategies in their answer".
Esther Weathers has made available an excellent document in which the pediatric airway caveats are explained, as well as the ways around them. Unfortunately, it is no longer available from www.westernschools.com. Lucky I was able to pillage it before it vanished. This table offered below was put together using the Weathers document, as well as the college answers from all the previous SAQs on this topic.
|And strategies that may be used to overcome these.
|How this is a problem
|Strategy to overcome this problem
|Neck is flexed in the supine poistion.
Laryngoscopy will be difficult in this position.
|Less anterior excursion; smaller mouth opening
|Large tongue relative to the size of the oral cavity. Causes airway obstruction and interferes with laryngoscopy.
|Larger tonsils and adenoids
|Can cause airway obstruction. Nasopharyngeal airways may cause bleeding and aspiration.
|Superior laryngeal position
|Located opposite the C3 to C4 vertebrae, compared with the C4 to C5 in adults. Laryngoscpy is made more difficult.
|Large, floppy epiglottis
|The epiglottis projects further into the airway and covers more of the glottis (until the age of 4)
|Easy to intubate the right main bronchus.
Easy to inadvertently extubate the child.
|More predisposed to obstruction: small decreases in the airway size will cause obstruction.
The needle or surgical cricothyroidotomy is more difficult, as the target is smaller.
One should also be concerned about the risk of tracheal stenosis following prolonged intubation or tracheostomy.
|Soft trachea and cricoid
|Cricoid pressure may collapse the airway
|Anatomic subglottic narrowing
|An effective anatomic seal can be expected without the need for a cuffed ETT. Foreign bodies can become lodged below the cords. This resolves by age 10-12.
Question 27 from the first paper of 2016 asked the candidates for "the key management issues" in securing an airway in the case of a child with stridor. The college model answer disappointingly lists "Call for help", "Choice of anaesthetic technique - inhalational versus intravenous" and "Failed intubation drill" which cannot possibly represent a passing level of effort. To expand upon this, I used to main references: Holm-Knudsen et al for "basic aspects" (2009) and Cardwell et al (2003) for "Management of the difficult paediatric airway."