Pediatric Airway Lesson 10 & 11 PDF

[Pediatric Airway ] - Anatomical differences - Head is larger in proportion to the rest of the body - Nose - Smaller in relation to trachea size - Infant is an obligate nose breather for first year of life - Tongue -...

[Pediatric Airway ] - Anatomical differences - Head is larger in proportion to the rest of the body - Nose - Smaller in relation to trachea size - Infant is an obligate nose breather for first year of life - Tongue - Larger tongue - Lack of muscle tone in jaw and pharynx will cause tongue to fall back and obstruct airway - Rests against roof of mouth during normal respiration - Airway differences - Airway shape - In peds funnel shaped - In adults cone shaped and doesn't reach that level until teenage years - Larynx - Higher in relation to c-spine than adult - Located at c3-c4 - Vocal cords - Adult cords sit perpendicular to the trachea - Pediatric cords have a lower point of attachment on anterior side of trachea - Hyoid bone in peds is firmly attached to thyroid cartilage which tends to push the base of the tongue and epiglottis towards the pharyngeal cavity - Pediatric cords slant forward and down - Cricoid cartilage = narrowest part of pediatric airway - Epiglottis - Omega shaped in pediatrics - Larger and stiffer than in adult - This is why Miller blades are recommended to directly lift epiglottis - Trachea and mainstem bronchi - Easier to mainstem because infant major airways are narrower and shorter - Mainstem bronchi divide more equally - Keep precordial stethoscope on left side of chest during intubation so you can immediately assess if you intubate the right mainstem bronchi - Infant have smaller airways - Resistance to airways is greater due to smaller diameter - Infants have less tolerance to edema - Ventilation in relation to body mass is greater due to high metabolic rate - Hypoxemia decreases the response of the neonate to hypercapnia - Any increase in ventilation is not well-sustained - Comparison of respiratory parameters - Infant - FRC is half TLC - RR 25-50 - Vt 6-8 mL/kg - O2 consumption 6-8 - Adult - RR 12-16 - Vt 7 ml/kg - O2 consumption 3 - Pediatric respiratory system - Closing volume is higher in pediatrics than adults - FRC is close to Vt so there is a smaller range in which optimal oxygenation happens - They will desat quicker - In pediatrics, the following will cause increased PVR -- hypoxia, hypercarbia, acidosis, hyperinflation, atelectasis, high Hct, surgical constriction - In pediatrics, the following in will cause decreased PVR -- oxygen, hypocarbia, alkalosis, normal FRC, sympathetic stimulation blocking, low Hct - CO is dependent upon HR secondary to fixed SV - Noncompliant LV - Cannot adjust SV to maintain CO so they must increase HR - Airway evaluation/examination - Recurrent pneumonia/respiratory infections can indicate frequent aspiration - Aspiration secondary to incompetent larynx, GERD, TEF, tracheobronchial fistula - Presence of URI can predispose pts to laryngospasm, bronchospasm, and airway edema (i.e. airway reactivity) for 4-6 weeks - Snoring and noisy breathing can indicate tonsillar/adenoid hypertrophy, OSA, or pulmonary HTN - History of croup, stridor, or traumatic/prolonged intubations can indicate subglottic stenosis - Environmental allergies and exposure to secondhand smoke can increase airway reactivity - Microtia = deformed ears -- associated with mandibular hyperplasia - 4 grades of microtia with 4 being the worst - Bilateral microtia = increased risk of difficult airway - Ventilation - Positioning for mask ventilation of neonate is normal head and neck alignment - Ensure neutral head and neck - May extend neck in older pediatric cases (like with adults) - NPA - Typically avoided to prevent trauma and bleeding from hypertrophied adenoids - Sizing is same as in adults from nose to angle of mandible - OPA - Tongue is large compared to oropharynx and often obstructs airway - Too large OPA = push the epiglottis down, impinge the uvula, and cause swelling - Too small = aggravate airway obstruction - Insertion during stage 2 may cause laryngospasm - Mask ventilation = used when pt can spontaneously breathe - Minimize pressure on soft tissues to prevent airway collapse - Normally used in quick, non-stimulating cases - Have all equipment necessary if you need to transition to intubation - LMA - Not a protected airway so you cannot ventilate if there is a laryngospasm - Contraindicated in aspiration risk, GERD - Substitute for mask anesthesia in spontaneous ventilating pts - Removal of LMA can be awake or deep - ETT sizing - Cuffed = age/4+3.5 - Uncuffed = age/4+4 - ETT depth = 3x diameter of ETT - ETT cuff - Want cuff leak at 20cmH2O - If cuff leak not present, may be ischemic damage to tracheal mucosa - Laryngoscopy - May need shoulder roll in neonate and small infants - Larynx is higher in neck so sniffing positing will worsen view of airway - MAC best for school-aged children - Miller best for neonates and small infants - Nasal intubation - Ventilation management - PCP preferred mode - Physiologic PEEP = PEEP 4-5 - O2 -- risk of retinopathy of prematurity until 44 weeks - N2O - analgesic - can use it to mask a pt down for induction and for extubation - Extubation = awake or deep -- no in between - Awake = fully emerged with protective airway reflexes - Advantages = protected airway during stage 2 - Disadvantages = ETT will be stimulating and can cause coughing and straining on emergence - Deep = - Advantages = less coughing, straining, retching - Disadvantages = non-protected airway, lack of protective airway reflexes make pts more prone to aspiration - Not recommended for airway surgery where bloody drainage is an issue - Airway obstruction - Inspiratory stridor = obstruction above larynx - Expiratory stridor = obstruction below larynx - Hoarseness =vocal cord involvement of obstruction - Biphasic stridor = at or below vocal cords - Airway obstruction interventions - Laryngospasm - NPPE - Difficult pediatric airway syndromes - Choanal atresia = congenital disorder characterized by blocked nasal passages - Sx = cyanosis at rest relieved by crying or insertion of oral airway - Avoid all nasal instrumentation - Clef lip/palate - Glossoptosis = tongue inserts more caudally - Micrognathia = increased risk difficult intubation regardless of cause - Down Syndrome - Atlantoaxial instability with or without subluxation - Frequently need smaller than anticipated ETTs - Characterized by small mouth, hypoplastic mandible, protruding tongue - Pierre-Robin - Treacher-Collins