New Orleans EMS Airway Lecture Series: Lecture 4 The Pediatric Airway Jeffrey M. Elder, M.D. Deputy Medical Director

Challenges of the Pediatric Airway Age related dosing and equipment Anatomical Variations based on age Anxiety of a sick child

Pediatric Airway Anatomy

Tongue Located completely in the oral cavity until 2 years old No portion makes up the upper/anterior pharyngeal wall Potential site of airway obstruction Difficult ventilation

Occiput A child’s head/occiput are proportionately larger than and adult’s Neck flexion while supine Leads to obstruction Overcome with the sniffing position (want EAC just anterior to the shoulders) Roll placed under back(infant) None – small child Roll placed under occiput

Positioning

Sniffing Position

Nasal Passage Increased mucosa and lymphoid tissue Nasal airway is primary pathway for normal breathing in the infant Warming, humidification, particle filtration Compromised breathing with increased secretions, NGT placement, nasal congestion

Larynx Newborns Larynx at the base of the occiput/C1 to C4 Enables epiglottis to lock the larynx into the nasopharynx by passing up behind the soft palate Provides a direct air channel from the nares to the lungs, allowing liquids to pass on the sides into the esophagus

Larynx Two separate anatomic pathways Large Tongue High Glottis Respiratory tract from the nose to the lungs Digestive tract from the mouth to the stomach Large Tongue Entirely within the oral cavity High Glottis Difficult line of vision from mouth to the larynx during laryngoscopy Anterior Airway

Anatomic Changes in Childhood Occurs after the second year of life Posterior 1/3 of tongue descends into the neck, forming upper anterior pharyngeal wall By 7 years, the larynx lies between C3 and C6 In adulthood, the larynx lies between C4 – C7 Now loose the two separate pathways

Anatomy In adults, the vocal cords and trachea are of equal dimensions In newborns, the narrowest portion of the airway is the cricoid ring Tight ET tubes may lead to cricoid damage, subglottic stenosis

Functional Issues Children easily obstruct the airway Racemic epinephrine can have dramatic results in the smallest areas of the airway (croup –cricoid ring) Larger airway calibers do not see such dramatic results (epiglotitis) – forced nebs can lead to dynamic upper airway obstruction Noxious stimuli can lead to dynamic obstruction and respiratory arrest Crying child increases work of breathing 32-fold – “leave them alone” BMV may bridge through an obstruction i.e. Epiglotitis Increased inspiratory effort may collapse the airway – (extrathoracic trachea) PPV can stent the airway open are relieve the obstruction

Physiology Basal Oxygen consumption is approximately twice that of adults Children have a decreased functional residual capacity (FRC) to body weight ratio Desaturate much more quickly!! Even given equivalent duration of preoxygenation Be prepared to provide supplemental oxygen by BMV if oxygen saturation drops below 90%

Airway Management

Evaluation History Observation PMHx, Prematurity, Previous Intubations Tachypnea Accessory Muscle Use Nasal Flaring Tripoding

Evaluation Position of comfort Grunting Cyanosis Drooling Wheezing Rales

Signs of Respiratory Failure Decreased level of consciousness Grunting and increased work of breathing Poor Air Entry / Decreased breath sounds Bradycardia Apnea/Slow Respiratory Rate

Reasons to Intubate Failure to Oxygenate Failure to Ventilate Expected Clinical Course

Airway Management

The 7 P’s of RSI Preparation Preoxygenation Pretreatment Paralysis with induction Positioning Placement with proof Postintubation management

Airway Equipment Suction Device Oxygen source Bag Valve Mask ET Tube 1 size smaller and larger Laryngoscope blade & Handle EtCO2 Detector Tube Holder Alternate Airway Equipment OPA, Combitube, LMA, cric. kit RSI Medications

Equipment Sizes ET Tube Diameter = (age/4) + 4 Width of child’s 5th fingernail Depth = Tube Size x 3 Uncuffed Tube for less than 8 years old Laryngoscope Blade Be careful of size 0 and 00 Based on Broselow Tape

Bag Valve Mask Ventilation Must fit over the nose, cheeks, mouth, and chin Place in sniffing position In line stabilization Jaw thrust OPA/NPA From ear to mouth Inspect for foreign body Cricoid pressure

Bag Valve Mask Ventilation Pediatric/Adult Size bag Pop off valve 35-45 cm of water A skill that needs practice! 1 or 2 person ventilation

Rapid Sequence Induction Etomidate 0.3 mg/kg Succinylcholine 2 mg/kg faster metabolism than adults Still first line for full-stomach or emergency intubation Rocuronium 1 mg/kg Atropine 0.02 mg/kg min. 0.1mg Lidocaine 1mg/kg SCh --Hyperkalemic cardiac arrest secondary to unDx neuromuscular disease

Endotracheal Intubation Usually after airway control and ventilation/oxygenation Preoxygenation Don’t bag – 3 minutes of 100% oxygen via BVM Pick the right equipment! Most effective and reliable airway management/protection Always a clinical decision

Endotracheal Intubation Attempts should not last over 30 seconds Straight or Curved blade Miller – picks up epiglottis Straight blades preferred in small children Picks of epiglottis directly and tongue/mandible more easily elevated from field of vision Macintosh – enter the vallecula

Post Intubation Management Verification of Tube Placement Visualization ETC02 Auscultation Secure the tube with tape or commercial device Head/neck immobilization in small children to avoid neck movement and dislodgement

Post Intubation Management Place NG tube after ETI Decompress the stomach Avoid micro aspiration in mechanically ventilated patients

Contraindications to RSI Major Laryngeal trauma Upper Airway Obstructions Distorted Facial/Airway Anatomy Operator Concern of Difficult Airway

The Difficult Airway

The Difficult Airway Direct Examination Large Tongue Mental-Hyoid Distance Upper-Lower Incisor Distance Large Tongue Blood, swelling, secretions Limited C spine mobility/scoliosis Limited mandibular ROM Maxillofacial/ Larynx trauma *Angoiedema *Anaphylaxis *Epiglottitis *Croup Morbid Obesity Micrognathia Burns Foreign Body

Adjunct Airways Combitube Only if > 4 feet tall Rescue Airway Device

Adjunct Airways LMA Rescue option in the failed airway May cause partial airway obstruction in infants (rotational placement) Loss of seal/movement Contraindicated in FB aspiration obstruction

Adjunct Airways LMA

Adjunct Airways Cricothyroidotomy Contraindicated < 10 yrs Needle Cric <10 yrs 14g needle, 5cc syringe, 3mm ETT adapter, BVM Can’t intubate, Can’t ventilate Trauma, angioedema, epigolttitis

Adjunct Airways Cricothyroidotomy

References Trauma Reports Volume 8, No. 1. Jan/Feb 2007. AHC Media, LLC. Managing the Pediatric Airway in the ED, Pediatric Emergency Medicine Practice. Volume 3, No. 1. January 2006 Manual of Emergency Airway Management, 3rd Edition. Walls, R. and Murphy, M. 2008.