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 O 2 /kg/min)  TV same; minute ventilation increased

Airway Anatomy Differences  Relatively larger head and tongue  More cephalad larynx (C 3-4 vs. C 5-6 )  “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% O 2, 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 (2 nd notch)  ETT ID X 3  Loss of breath sounds (carina), pull out 2 cm  Cuff palpable in sternal notch

Treacher Collins Syndrome

Klippel-Feil 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 O 2 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”