Intubation and Tracheotomy

1

What are common airway grading systems to consider prior to intubation?

Friedman Palate Position ( Fig. 79.1 ):

• I

  Visualization of entire uvula and tonsils/tonsillar pillars

• II

  Visualization of the uvula but not tonsils

• III

  Visualization of the soft palate but not uvula

• IV

  Visualization of hard palate only

Similarly, the Mallampati Score (more commonly used in anesthesiology):

• Class I Soft palate, uvula, fauces, pillars visible

• Class II Soft palate, uvula, fauces visible

• Class III Soft palate, base of uvula visible

• Class IV No soft palate visible

The higher the score, the more difficult exposure of the larynx may be during intubation.

2

What does the size of the endotracheal tube refer to?

The number refers to the inner diameter of the endotracheal tube. Thus a 5.0 ET tube will have an inner diameter of 5 millimeters, a 5.5 ET tube will have an inner diameter of 5.5 millimeters, and so on. The outer diameter of the ET tube can vary according to the material, manufacturer, and type of tube.

3

How can you quickly estimate the properly sized endotracheal (ET) tube for children?

• Cuffed tube = age 4 years + 3 years

• Uncuffed tube = age 4 years + 4 years

This is generally accurate for children aged 1 through 12 years.

4

How are ET tube sizes chosen for other patients?

See Table 79.1 .

As a general rule, between two ET tube sizes, it is safer to put in a slightly smaller ET tube rather than one that is too large and difficult to pass. If ventilation is difficult with a small tube, some ventilation can be administered to stabilize the patient, and a tube exchanger can be used to change the ET tube, with a very low risk of losing the airway.

5

What is the common airway classification measured during intubation?

Cormack-Lehane Classification grades the view of the larynx during direct laryngoscopy:

• Grade I Visualization of the entire glottis

• Grade II Partial view of the glottis; may see only arytenoids

• Grade III Visualization of the epiglottis only; none of the glottis is seen

• Grade IV Not even the epiglottis is visible

6

What are the typical sounds of obstruction at different levels of the airway?

• Trachea – usually expiratory, occasionally inspiratory

• Subglottis – biphasic stridor, barking cough, hoarse voice

• Glottis – biphasic or inspiratory stridor, hoarse voice

• Supraglottic – inspiratory stridor, muffled voice, inability to feed, no cough

• Oropharynx/nasopharynx – stertor, muffled voice, or hyponasal voice

7

What are some conservative interventions for upper airway obstruction?

Chin lift with jaw thrust, oropharyngeal airway , and nasopharyngeal airway are anatomical manipulations that can help alleviate upper airway obstruction. The first two are generally used for unconscious patients. The latter is best used for patients with oral obstruction (i.e., trauma, Ludwig’s angina) or in neonates with nasal obstruction who are obligate nasal breathers. Heliox can be used to deliver oxygen in cases of airway obstruction. Heliox is a mixture of helium and oxygen and is a lower-density gas compared to room air or pure oxygen. This allows a higher flow rate, which reduces turbulent flow past an obstruction and delivers more oxygen distally to the lungs. This reduced turbulent flow also decreases the pressure gradient needed to move air across an obstruction, thus reducing airway resistance and breathing. Typical concentrations are 21%:79% oxygen to helium. Helium is inert, insoluble in human tissues, and noncombustible. Heliox is used as a temporizing measure while planning to perform a more definitive airway stabilization.

8

What other noninvasive interventions can improve upper airway obstruction?

• Racemic epinephrine – administered via nebulizer to cause vasoconstriction and reduce mucosal edema. Racemic epinephrine has been shown to help treat croup and postextubation stridor from laryngeal edema. Racemic epinephrine is not as effective for epiglottitis, and the practice of trying to administer it can be dangerous because agitation for these patients can cause acute obstruction by the swollen epiglottis.

• IV steroids – glucocorticoids, such as dexamethasone, are used to reduce airway inflammation and edema. This is thought to occur through reduced capillary dilation, decreased plasma extravasation, and inflammatory mediator release. They are also indicated for croup and laryngeal edema and are often used for other causes of upper airway obstruction (i.e., abscess or other infectious edema, including epiglottitis and angioedema). IV steroids act gradually, unlike racemic epinephrine, which acts fairly rapidly.

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