Management of the Pediatric Airway

Paul W. Sheeran, MD

Dept of Pediatrics

Division of Critical Care

Dept of Anesthesiology &

Pain Management

UTSW Medical Center

Outline

Differences in pulmonary physiology and airway anatomy

Mask ventilation and intubation techniques Evaluation of the upper airway Pediatric laryngoscope blades Sizing of ETT and depth of ETT Predictors of difficult intubation Management of the difficult airway

Pulmonary Physiology Differences

Compliant chest wall Airway collapse at low lung volumes Low FRC (desaturate quickly) High oxygen consumption (6-10 cc

O2/kg/min)

TV same; minute ventilation increased

Airway Anatomy Differences

Relatively larger head and tongue More cephalad larynx (C3-4 vs. C5-6)

“More anterior larynx” Narrowest part of the airway: cricoid cartilage Long epiglottis (floppy, omega shaped) Easily compressed trachea

Adult Glottis

Pediatric and Adult airways

Mask Ventilation Technique

Sizing of Oral Airway

Intubation Technique for Neonate

Induction Techniques

Mask induction (most children): Place monitors 8% sevoflurane in oxygen/nitrous oxide (5L/2L) When asleep: decrease sevoflurane to 4-6%, place PIV,

100% O2, administer NMB, and intubate IV induction (RSI, adolescents, in situ PIV):

Place monitors and pre-oxygenate Administer: Pentothal 6 mg/kg or propofol 3 mg/kg and

NMB Intubate

Upper Airway Evaluation

Mouth opening Size of the jaw Thyromental distance Mallampati classification

Class I: entire uvula visible Class II: part of uvula hidden by tongue Class III: only soft palate visible Class IV: only hard palate visible

Neck range of motion (extension AO joint)

Mallampati Classification

Cormack and Lehane Grades

Miller laryngoscope blades

Phillips laryngoscope blades

Mac laryngoscope blades

Pediatric Laryngoscope Blades

Types: Miller Philips Mac

Newborn: Miller 0 1 month - 1 year: Miller 1 1–3 years: Philips 1 4-8 years: Mac 2 >8 years: Mac 3, Philips 2, or Miller 2

Difficult Airway due to Dysmorphia

Decreased mandibular space (limited mouth opening) Micrognathia, retrognathia, mandibular hypoplasia Pierre- Robin, Treacher Collins

Decreased head extension (RA, Klippel-Feil) Increased tongue size or space-occupying

lesion (e.g., cystic hygroma)

Guides for Proper ETT Sizing

ETT size:

Newborn: 3.5 mm 4 months-1 year: 4.0 mm Older child: 4 + (age in years/4)

Depth of ETT Direct visualization (2nd notch) ETT ID X 3 Loss of breath sounds (carina), pull out 2 cm Cuff palpable in sternal notch

Treacher Collins Syndrome

Treacher Collins Syndrome

Klippel-Feil Syndrome

Hunter’s Syndrome

Hunter’s Syndrome

Other Indicators of Difficult Airway

Burns to the face and neck

A history of radiation to the head and neck

A history of difficult intubation (i.e., read old anesthesia records if available)

Other Causes of Difficult Intubation

Oral bleeding and swelling (e.g., mucositis, Steven’s Johnson Syndrome, or recent T&A)

Copious oral secretions (e.g., RSV, ARDS, pulmonary hemorrhage)

Severe cardiac dysfunction (e.g., myocarditis, sepsis)

Difficult Airway Management

Anticipate problems: Call for help Place PIV pre-op Administer glycopyrolate (10 mcg/kg IV or IM) one hour prior

to intubation Keep patient spontaneously breathing (no NMB) Techniques

Fiberoptic intubation (FOI) LMA placement alone (no ETT) LMA placement followed by FOI Light wand-assisted oral intubation

Acquired Difficult Airway

Epiglottitis/supraglottitis

Croup

Foreign body

Trauma

Epiglottitis/supraglottitis

Acute inflammation of the epiglottis, aryepiglottic folds, arytenoids, and supraglotis

School-aged child presents with high fever, drooling, and inspiratory stridor

Causes: bacteria or caustic ingestion Do not examine with a tongue blade Take to the OR

Mask or IV induction without paralysis Rigid bronchoscopy by ENT

Croup

Gradual onset of inspiratory stridor and “barky” cough in young children (<3 years)

Subglottic narrowing (steeple sign on CXR) Treatment:

Cool mist Nebulized racemic epinephrine Intubate if patient is in respiratory failure

(smaller ETT than expected is typically needed)

Foreign Body Aspiration

Young child with either

Acute h/o choking Chronic h/o pneumonia or refractory wheezing/cough

Stable patients may be X-rayed Unstable patients: intubated and then taken to the OR

For esophageal FB: RSI, intubation, and

esophagoscopy For laryngeal FB:

Mask or IV induction (without NMB) Rigid bronchoscopy by ENT surgeon

Upper Airway Trauma

Neck trauma may cause laryngeal and/or tracheal injuries Presenting symptoms: SQ air, neck swelling, hypoxia If the patient is in extremis in the E.R.

IV ketamine and glycopyrolate Intubate orally Confirm ETT location prior to NMB

If the patient is stable, then take to the O.R. Mask or IV induction without paralysis Tracheotomy by ENT Oral intubation is controversial

Summary

Pediatric patients have a small FRC and increased O2 consumption: pre-oxygenate with CPAP

It is imperative to evaluate the airway prior to administering paralytic agents

Difficult intubation associated with micrognathia, decreased head extension, and a large tongue

Problems with patients with a difficult airway should be expected: “Don’t go down alone”