Transcript New Orleans EMS Airway Lecture Series: Lecture 4 The Pediatric Airway Jeffrey M.

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
– 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
– PMHx, Prematurity, Previous Intubations
• Observation
– Tachypnea
– Accessory Muscle Use
– Nasal Flaring
– Tripoding
Evaluation
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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
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Preparation
Preoxygenation
Pretreatment
Paralysis with induction
Positioning
Placement with proof
Postintubation management
Airway Equipment
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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
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
– 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.