Evaluation of pediatric upper airway
C. GysinORL-Unit
University Children’s Hospital Zurich
SSORL-Ecole d’été – SGORL-Sommerschule 2019
Pediatric airway – anatomy
• large head• short neck• small nares• small mandible• pliable trachea and chest wall• immature alveolae• gastric dilatation, reflux• high metabolic rate• friable mucosa
• high larynx• cricoid cartilage = C4
• long epiglottis• lies against the soft palate
• long uvula• neonate obligate nasal breather
Pediatric airway – anatomy
prominent cuneiform cartilages
short aryepiglottic folds tendency to collapse during inspiration
epiglottis omega-shaped
glottic length 50% ligamentous – 50% cartilaginous (adults 80-20)
Pediatric airway – anatomy
• subglottis:– from conus elasticus to inferior part of
cricoid cartilage– only complete ring of the larynx and trachea– narrowest region of the pediatric airway
• subglottic diameter at birth:– cricoid cartilage: 5.5mm– full-term baby: 4.5-5.5mm– premature baby: 3.5mm
Pediatric airway – anatomy
↓ diameter 1mm = ↓ surface 50%⇒ resistance R = 8µL/πr4
Pediatric airway – anatomy
Newborn Child Adult
Normal
subglottic diameter (mm) 4 8 14
subglottic radius (mm) 2 4 7
subglottic surface (mm2) 12 6 12
1mm edema
subglottic diameter (mm) 2 6 12
subglottic radius (mm) 1 3 6
subglottic surface (mm2) 3 27 108
Diminution of subglottic surface 75% 44% 27%
Pediatric airway – anatomy
Clinical approach
1. age of onset of respiratory symptoms?2. level of obstruction?3. investigations? 4. what is the lesion?
congenital acquired
infection trauma
foreign body
Pediatric airway obstruction
• newborn = congenital• 1-3 years = acquired more likely• >3 years = acquired likely (congenital highly unlikely)
tumor
Diagnosis and age of onset of respiratory symptoms
since birth: bilateral vocal cord paralysis congenital subglottic stenosis bilateral choanal atresia
first 2 weeks of life: laryngomalacia 1-3 months: subglottic hemangioma > 6 months: pseudocroup foreign body epiglottitis
narrowing of the airway
abnormal flow or turbulence
noisy breathing(stridor/stertor)
Pediatric airway – clinic
Clinical evaluation – noisy breathing
• Stertor– nasopharynx, oropharynx– ‘low-pitch’
• Stridor– larynx, trachea (extra-tracheal)– inspiratory vs expiratory!!!– biphasic: subglottis
• Wheezing– trachea (intrathoracic), bronchi
Pediatric airway – evaluation
medical history clinical evaluation radiological examination endoscopic evaluation
Pediatric airway – medical history
Pediatric airway – clinical evaluation
noisy breathing: constant, intermitent dyspnoe, tachypnoe intercostal retraction, tracheal tugging, nasal flaring cyanosis feeding and breathing: aspiration, cough, cyanosis nose, mouth and oropharynx and the examination of larynx?
Pediatric airway - radiology
not routinely!
Rx-Thorax CT-ScanMRI
Pediatric airway – endoscopic evaluation
> 4 years: endoscopy without anesthesia possible, but not below glottis endoscopy under general anesthesia: spontaneous breathing with the flexibel scope to assess the fonction rigid endoscopy to evaluate the anatomy completely, most of the time in
apnea always examine the whole airways!!! There might be a second lesion!!!
Pediatric airway – endoscopic evaluation
good collaboration with the anesthetist always have an iv access before endoscopy always have a bronchoscope in the OR
!!!no coniotomy!!!
Pediatric airway – endoscopic evaluation
• nasopharyngolaryngoscopy– flexibel
spontaneous breathing (dynamic)• laryngotracheoscopy:
– rigidunder relaxation (anatomy)
• microlaryngoscopy• bronchoscopy
Positioning of the patient for the endoscopy (rigid)
Instruments rigid bronchoscopy
Size of the rigid bronchoscope
Size of bronchoscope Outer diameter (mm) Age
2.5 4.0 premature – newborn
3.0 5.0 newborn – 6 months
3.5 5.7 6-18 months
4.0 7.0 18-36 months
5.0 7.8 3-8 years
6.0 8.2 > 8 years
Telescopes 0°/30° 20 or 30 cm length
Pediatric airway obstruction – nose
choanal atresia/ choanal stenosis piriforme aperture stenosis cleft lip and palate craniofacial malformations Treacher-Collins, Crouzon
arrhinie (agenesia of the nose) proboscis lateralis congenital cysts midline deficiency Encephalocele, Meningoencephalocele
chordoma, hamartoma
Bilateral congenital nasal obstruction
acute respiratory distress ⇒ emergency intermittent cyanosis relieved by crying clinical evaluation: nose
external aspect of the nose 5Fr/6Fr suction catheter via nostrils laryngeal mirror test
stethoscope
oral cavity other malformations
feeding difficulties
definition: anatomical closure of the posterior choanae incidence: 1:5000 - 1:8000 births “2:1 rule”: 2w : 1m 2unilateral : 1bilateral 2rights : 1left
associated syndromes: CHARGE, Treacher-Collins, Apert-Crouzon, Pfeiffer… diagnosis: 5-6 Fr catheter via nostrils: obstruction 3-3.5 cm, nasal endoscopy, CT-scan treatment: transnasal endoscopic opening of choanae
Choanal atresia
Pyriform apertura stenosis
definition: bony overgrowth of the nasal process of the maxilla (anterior nasal stenosis) incidence: 1:50’000 births diagnosis: CT associated anomalies: megamaxillary incisor,
holoprosencephaly treatment: milder forms: conservative therapy, otherwise
surgery
Congenital nasal tumors
teratomas hamartomas rhabdomyosarcoma …
teratomas/hamartomas may arise fromthe nasopharynx, same symptoms as congenital nasal masses, oft associatedcleft palate
Bilateral congenital nasal obstruction – summary
diagnosis: endoscopy examination of the oral cavity radiological evaluation before any surgery! CT MRI
acute management depending on the etiology and severity of obstruction: special pacifier (dummy): McGovern nipple, with an opening oroendotracheal Intubation tracheotomy in complex syndromal malformations
Cleft lift and palate
1:800 births 85% isolated >200 syndromes associated with cleft lip and palate significant upper airway obstruction at birth mostly
with associated malformations /syndrome Pierre Robin sequence: retrognathia glossoptosis cleft palate + other malformations = syndrome (50%)
craniofacial malformation: Pierre-Robin sequence (retrognathia, glossoptosis, cleft
palate) Treacher-Collins Crouzon trisomy 21
vallecular cyst lingual thyroid/thyroglossal duct cyst
Pediatric airway obstruction – pharynx
Craniofacial malformations
Crouzon Treacher-Collins
complex malformationsoft associated with cleft palate/choanal atresia! multilevel upper airway obstructionoft tracheotomy
congenital• laryngomalacia• subglottic stenosis• bilateral vocal cord paralysis• saccular cyst, laryngocele• laryngeal web• laryngeal cleft• lymphangioma
Pediatric airway obstruction – larynx
acquired• subglottic stenosis• subglottic hemangioma• laryngeal papillomatosis• granuloma• angioedema• epiglottitis• foreign body• trauma
Laryngomalacia
incidence: most common cause of newborn stridor (35-75%) clinical signs: inspiratory stridor that worsens with feeding, agitation, crying,
and supine positioning natural history: symptoms worsen at 4-8 months, improve between 8 and
12 months, and usually resolve by 12-18 months of age classification: mild (40%): conservative management moderate (40%): complicated with regurgitation, coughing, and choking
episodes with feeding. severe: (20%) failure to thrive, feeding problems, aspiration, apnea, hypoxia,
recurrent cyanosis, cor-pulmonale, will require surgery
Laryngomalacia
etiology: theory of neuromuscular alteration in laryngeal tone and resultant prolapse of supra-arytenoid tissue and supraglottic collapse causing airway obstruction diagnosis clinical history endoscopy: supra-arytenoid tissue prolapse during inhalation, omega-shaped
epiglottis, retroflexed epiglottis, short aryepiglottic folds, poor visualization of the vocal folds, and edema of the posterior glottis
management: conservative proton pump inhibitors supraglottoplasty
Subglottic stenosis
congenital: more likely to be associated with a syndrome (Down!) acquired: < 1% of neonates with a history of prolonged intubation clinical signs: biphasic stridor, associated symptoms depending on the
severity of the symptoms grading-system nach Cotton-Myer: grade I: up to 50% stenosis grade II: 51% to 70% stenosis grade III: 71% to 99% stenosis grade IV: no lumen
Subglottic stenosis
management: grad I: conservative (recurrent croups!) more severe forms: endoscopic: laser, balloon dilatation, anterior split, posterior split external approach: laryngotracheoplasty, cricotracheal resection tracheotomy
"prevention": Down patients should be intubated with an endotracheal tube 1 full size smaller tube than the age-appropriate as a result of a smaller airway diameter and higher incidence of congenital subglottic stenosis
Subglottic hemangioma
hemangioma: most common congenital vascular, can be seen everywhere in the airway, predilection for subglottis 2 f : 1m beginn of symptoms between 4-6 weeks of age clinical signs: 50% of patients have also cutaneous hemangiomas biphasic stridor hoarse voice airway obstruction
! recurrent croups < 6 months of age! diagnosis: endoscopy management: beta-blocker (propranolol)
Epiglottitis
definition: acute inflammation and edema of the epiglottis and surrounding tissues leading to progressive airway and a potentially life-threatening condition peak incidence: 2-4 years old Haemophilus influenza type B (Hib), but since vaccination other strains observed
(group A beta-hemolytic streptococcus, Streptococcus pneumonia, Klebsiella sp, and Staphyloccocus aureus incidence: 1.3 cases per 100’000 since vaccination against Haemophilus
influenza type B (Hib) abrupt onset of symptoms: high fever, sore throat, irritability, drooling, muffled
voice, and progressive respiratory distress
Epiglottitis
clinical signs: children appear toxic respiratory symptoms contribute to a high level of anxiety patients prefer resting in the tripod position (leaning forward with jaw
protrusion) management: avoid procedures that increase the child’s anxiety until after their airway is
secured observation in ICU or direct laryngoscopy and intubation antibiotic treatment steroids
Foreign body
epidemiology: mostly < 4 years, peak incidence 1-2 years clinical presentation: be alert! 50% of cases occur without a choking event
having been witnessed clinical signs: vary based on the location of the foreign body and the degree of
obstruction may change over time as the foreign body might move within the
respiratory tract ! oesophageal foreign body and airway obstruction
thorax X-ray including posteroanterior (PA) and lateral views secondary signs of FBA such as overinflation, opacification, or atelectasis of
the distal lung
Priority: according to history and symptoms
Scenario 1Awake /alert, a history of aspiration, no symptoms
"silent" foreign body?dislocation, poststenotic complications
Scenario 2Awake, acute airway obstruction, coughing w/ or w/o dyspnea
Bronchoscopy asap, observation in ICU until then,Transfer: prepared for intubation
M. Weiss et al, Notfall und Rettungsmed 2012,15:111-116
Priority: according to history and symptoms
Scenario 3Awake, acute obstruction, danger of asphyxia, effective cough
Straight to bronchoscopyTransfer: prepared for intubation
M. Weiss et al, Notfall und Rettungsmed 2012,15:111-116
Priority: according to history and symptoms
Scenario 4awake, airway obstruction, ineffective/absent/missing cough, danger of asphyxia
support coughtransfer for bronchoscopy
Scenario 5unconscious, acute airway obstruction
Mask ventilation, intubationResuscitation
tracheomalacia intrinsic, i.e. oesotracheal fistula extrinsic compression vascular anomalies tumors
posterior laryngeal clefts complete tracheal rings
Pediatric airway obstruction – trachea