Week 10 - Pediatric Airway Considerations Flashcards
How does the neonatal airway compare to adults?
Structures are:
- smaller
- more anterior
- larynx is higher (C3-4) vs adults (C4-5)
- hyoid bone at C2-3 in neonate to 2 yrs
- floppier epiglottis
- larger tongue
- larger occiput
- cricoid cartilage is the most narrow location vs vocal cords in adults
What is significant about a higher larynx in infants?
- The distances between the tongue, hyoid bone, epiglottis, and roof of mouth are smaller
- More likely for tongue to easilty obstruct the infant’s airway
- Tongue is closer to superior larynx making visualization of laryngeal structures more difficult – straight blade is helpful
How is the epiglottis different in infants than the adult?
Narrower
Omega shaped
Angles away from axis of trachea
*makes it more difficult to lift compared to adult’s
How are the vocal folds different in infants than the adult?
Vocal folds in infants have lower (caudad) attachment anteriorly than posteriorly, altering angle at which tracheal tube approaches laryngeal inlet
*can make intubation more difficult
What happens in the ETT tube is too big in an infant?
Cricoid is the only complete ring of cartilage and therefore doesn’t expand – Tight fitting ETT compresses tracheal mucosa and can cause edema –> reducing the luminal diameter of the upper airway and increasing airway resistance (post-extubation croup)
-subglottic region in infant is smaller than adult, same degree of airway edema is more compromising in the infant
What is the physiologic difference in respiration for infants?
Infants are obligate nasal breathers until 3-5 months
- obstruction of anterior or posterior nares including nasal congestion, stenosis, choanal atresia may cause asphyxia
- because of more cephalad position of larynx, during quiet respiration, the tongue rests against roof of mouth = oral airway obstruction
How are normal airway dynamics altered with obstruction of the extra-thoracic trachea in infants?
Inspiration against an obstruction leads to development of more negative intra-thoracic pressure –> dilating intrathoracic airway to greater degree
Net effect is increased tendency toward dynamic collapse of extra-thoracic trachea below level of obstruction –> prominent inspiratory stridor
*with intra-thoracic tracheal obstruction (vascular ring or fb) stridor may be both during inspiration and expiration
What might cause significant intra-thoracic tracheal and bronchial collapse in the infant?
Asthma, bronchiolitis
- occurs as a result of prolonged expiratory phase and increased positive extraluminal pressure
- because airways are very compliant, may be more susceptible to closure during bronchial smooth muscle contraction
*preterm and term infants may have airway closure even during quiet respirations
How do you evaluate the pediatric airway?
- Hx of congenital syndrome?
- Any physical findings of congenital anomaly
- Presence or recent hx of URI
- Snoring or noisy breathing
- Presence and nature of cough
- Past episodes of croup
- Inspiratory stridor
- Hoarse voice
- Asthma and bronchodilator therapy
What is included in a physical exam/observation of respiratory function in an infant?
- Look for facial expressions
- Presence or absence of nasal flaring
- Presence or absence of mouth breathing
- Color of mucous membranes
- Presence or absence of retractions
- Respiratory rate
- Presence or absence of voice changes
- Mouth opening
- Size of mouth
- Size of tongue
- Loose or missing teeth
- Size/abnormalities to palate
- Size of mandible
- Location of larynx in relation to mandible
- Baseline O2 sat
What are mask ventilation considerations for the infant?
- Be careful not to compress the submental triangle with fingers placed below the mandibular ridge (will partly occlude airway)
- Minimal pressure is required
- Fingers should rest on mandible
- Tongue easily sticks to palate
- Hand on ventilating bag at all times –> monitors effectiveness of ventilation and can apply CPAP
How should children be positioned for tracheal intubation?
Children >6: small pillow or blanket under the head may be beneficial to achieve sniffing position
Small Children/Infants: head is large in relation to rest of body –> usually elevating head is not helpful – use of shoulder roll may be beneficial
What typical laryngoscope blades are used for the following ages?
- Preterm
- Neonate
- Neonate - 2 years
- 2-6 years
- 6-10 years
- 10+
Preterm: Miller 0 Neonate Miller 0 Neonate - 2 years: Miller 1 or Mac 0-1 2-6 years: Wis-Hipple 1.5 or Mac 1-2 6-10 years: Miller 2 or Mac 2 >10 years: Miller 2-3 or Mac 3
What are the typical endotracheal tube sizes for the following ages?
- Preterm 1000g
- Preterm 100-2500g
- Neonate - 6 months
- 6 months - 1 year
- 1-2 years
- Older than 2
Preterm 1000g: 2.5 mm Preterm 100-2500g: 3.0 mm Neonate - 6 months: 3.0 - 3.5 mm 6 months - 1 year: 3.5 - 4.0 mm 1-2 years: 4.0-5.0 mm Older than 2: Age/4 + 4
*subtract 1/2 size for cuffed ETTs
How do you determine ETT depth for pediatric population?
Age (yrs) / 2 + 12 for estimate depth
or
Height in cm / 10 +5 for ETT or + 7 for NTT
*in general, stop just after vocal cords – easy to mainstem but also easy to extubate
