P DOWN SYNDROME X SLEEP BRADYCARDIA

Down Syndrome Airway

BY SEAN M. FOX · PUBLISHED FEBRUARY 26, 2016 · UPDATED FEBRUARY 7, 2017

The Ped EM Morsels strive to reinforce the notion that children are not an “alien population,” and while they deserve special attention, they should not be feared by us.  Children are, rather, a unique population that requires special consideration of the differences in anatomy and physiology (ex, Sinus Bradycardia, Aortic Trauma, Back Pain, Traumatic Pneumothorax).  What is equally important to remember is that within the pediatric population as a whole, there exists other unique populations that require even further appreciation of anatomic and physiologic variances.  Children with Down Syndrome deserve such specific consideration… particularly with respect to the Down Syndrome Airway.

Down Syndrome

• Down Syndrome, Trisomy 21, is the most common chromosomal disorder.
• It has characteristic phenotypic features, but these can have variable expression in individuals.
• It has increased incidence of a wide variety of associated medical conditions.

Down Syndrome Emergent Considerations:

• See Down Syndrome Considerations for details of these conditions that are associated with Down Syndrome.
  • Congenital Heart Disease
  • Seizure Disorders
  • Relative Immunodeficiency 
  • Hematologic Disorders
  • Atlantoaxial Instability
  • Diabetes Mellitus
  • Intestinal Obstruction
  • Hirschsprung’s Disease
  • Hypothyroidism

• Down Syndrome is associated with increased risk for respiratory illness.
  • Respiratory illness is a significant cause of hospitalization for children with Down Syndrome. [So, 2007]
  • Anatomic factors lead to greater risk of developing distress:
    • Upper airway is narrow
      • Smaller mid-face and lower face skeleton [Uong, 2001]
      • Macroglossia
      • Narrow nasopharynx
      • Relatively larger tonsils and adenoids
      • Short palate
      • Laryngomalacia is a common cause of airway obstruction in Down Syndrome patients. [Hamilton, 2016; Mitchell, 2003]
    • Trachea is smaller
      • The entire trachea is smaller in caliber (not just subglottic portion). [Shott, 2000]
      • Tracheomalacia associated with Down Syndrome is also common. [Hamilton, 2016]
      • Increased incidence of subglottic stenosis. [Hamilton, 2016; Miller, 1990]
    • Cilia are less functional
      • Potentially due to injury from prior infections.
      • Mucous is not mobilized as well.
    • Hypotonia and Obesity further complicate matters!

Down Syndrome Airway: Intubation Considerations

• Ideally, your timely therapies would help avoid the need for intubation, but…
• If intubation is required, keep in mind the following:
  • Pre-oxygenation is going to be vital!
    • Children are more prone to hypoxia during intubation; Avoid Desats!
    • Down Syndrome children will have a smaller Function Residual Capacity (FRC) due to the smaller airway.
    • This smaller FRC, in theory, will lead to less reservoir for you to fill up with 100% oxygen.  Less reservoir, leads to less oxygen reserve and early desaturations.
  • Positioning can make your task “easier.“
    • Obesity and hypotonia can further complicate ventilation once the child is fully supine.
    • Consider a slight Reverse Trendelenburg position (feet lower than head).
    • This can help displace the obese abdomen off of the chest.
    • This can also help improve alignment of the external auditory meatus with the sternal notch (so the trachea axis and oropharyngeal axis are better aligned).
  • Keep the C-Spine Stable!
    • Children may be previously asymptomatic with cervical spine instability.
    • Anesthesiologists’ practice varies and some advocate for pre-op radiographs and others for maintaining in-line stabilization. [Lewanda, 2016]
    • In the emergent setting, it is likely best to appreciate the risk of atlantoaxillary instability and take efforts to avoid injury.
      • Ideally, a basic neuro exam to assess motor and strength prior to intubation should be performed. [Lewanda, 2016]
      • Utilizing techniques to minimize neck manipulation is wise (Consider Glidescope).
      • Maintain in-line stabilization during intubation.
  • Use a smaller ETT!
    • We know that the Down Syndrome Airway is smaller and that the trachea is smaller in caliber.
    • It is recommended by anesthesiologists to use a ETT 2 sizes smaller! [Lewanda, 2016; Watts, 2013]
    • Would also advocate for a cuffed ETT to help make adjustments easier.
  • Be alert for Bradycardia.
    • One of the most frequent complications noted by anesthesiologists is Bradycardia. [Borland, 2004]
    • We have discussed previously how Atropine does not fix Hypoxia, and that techniques to avoid hypoxia need to be optimized.
    • It is unclear if patients with Down Syndrome have bradycardia due to hypoxia or inhaled anesthetic (i.e., sevoflurane: which we don’t use in the ED), but it is reasonable to be on alert for bradycardia. [Lewanda, 2016]