Treatment of Pediatric Airway Disorders: Beyond Tracheostomy Meredith N. Merz, M.D. Nationwide Children’s Hospital Department of Pediatric Otolaryngology April 6, 2011 Objectives 1. Identify the most common causes of stridor in the pediatric population. 2. Discuss diagnostic techniques in a child with stridor. 3. Understand the pathogenesis of acquired subglottic stenosis and the difference between congenital and acquired stenosis. 4. Discuss treatment options for the most common airway disorders in children. Laryngeal Function • Three Main Functions: 1. Acts as an airway from pharynx into trachea and lungs 2. Instrument of phonation 3. Protects the lower airways • Closure of glottis during swallowing • Epiglottis folds posteriorly over glottis • Cough Infant Larynx • • • • • • Larynx is more rostral Epiglottis apposes the soft palate Hyoid bone is impacted on thyroid cartilage Vocal cords are oriented transversely Epiglottis is short and curled in on itself Arytenoids are anteriorly oriented and involve half the length of the vocal folds Infant Larynx Bosma JF. Anatomy of the Infant Head. Baltimore, Johns Hopkins University Press, 1986, pp 366-367. Stridor • Harsh sound caused by turbulent airflow • Implies partial airway obstruction • Location of lesion determines character of stridor o Supraglottic o Extrathoracic o Intrathoracic Physics Review… • Poiseuille’s Law Q = [πd4 (P1-P2)] / 128ν Flow within a system is related to the radius of the tube to the fourth power Resistance is related to the inverse of the radius to the fourth power • Bernouilli’s Law: W = PAv As velocity increases through a constant area the pressure on the wall of the lumen decreases A region of anatomic narrowing is predisposed to collapse further with increased turbulent airflow Effect of Airway Narrowing Localizing Stridor • Supraglottic obstruction o With inspiration the loosely supported supraglottic structures collapse. Increased turbulence causes increased constriction o Stridor is inspiratory and high pitched • Extrathoracic obstruction o Airway is affected equally by inspiration and expiration o Stridor is biphasic, often accompanied by increased work of breathing • Intrathoracic obstruction o Relative positive pressures of expiratory forces narrow the airway lumen, resulting in increased constriction o Stridor is expiratory and “musical”; Wheeze Airway Evaluation- History • • • • • • • • Age at onset Onset: acute, chronic, progressive Prior respiratory problems Birth history Prior intubation GERD symptoms Wheezing episodes Feeding problems: o FTT, weight gain • Choking episodes • Aggravating factors Airway EvaluationInitial Examination • Inspection o General appearance and position, color, retractions, level of consciousness • Auscultation o Mouth/Nose, Neck and Chest • Repositioning o Prone/Supine, lateral, jaw thrust • Is there acute distress? o o o o o Nasal flaring Tachypnea Cyanosis Retractions Tripod position Flexible Nasopharyngoscopy • Gold Standard for office evaluation • Assess nares/ choanae • Assess adenoid and lingual tonsil • Assess laryngeal structures • Assess TVC mobility • Drawback: Poor for assessing subglottic structures Radiologic Evaluation • Plain films have limited utility o PA/ Lateral Neck • Airway Fluoroscopy o Evaluate the dynamics of respiration • Inspiratory/ Expiratory CT Scan Rigid Laryngoscopy and Bronchoscopy • Indications: o To establish diagnosis or evaluate for synchronous lesions (after flexible exam) o Severe or progressive stridor o Cyanosis or apnea concerns o Radiologic abnormalities o Parental or physician anxiety o Foreign body evaluation Rigid Laryngosocpy Rigid Bronchoscopy Congenital Disorders of the Larynx • • • • Laryngomalacia Congenital subglottic stenosis Vocal cord paralysis All Others: o o o o 60% 16% 13% 7% Congenital laryngeal web Laryngocele and Saccular cyst Laryngeal/ Laryngotrachealesophogeal Cleft Vascular lesions Holinger, LD. Etiology of Stridor in the Newborn, Infant, and Child. Annals of ORL, 1980; 89: 397-400. Laryngomalacia • Most common cause of stridor in infants • Presentation o Staccato/ Coarse inspiratory stridor o Worse with exertion, feeding, crying o Noisy breathing generally begins at about 2-4 weeks of age • Office Evaluation o Character of stridor o Positional changes o Flexible nasopharyngoscopy Laryngomalacia • Endoscopic appearance o Omega epiglottis o Foreshortenend aryepiglottic folds o Cuneiform and corniculate prolapse Laryngomalacia Classification Type I Type II Type IV Type III Type V Kay DJ, Goldsmith AJ. Laryngomalacia: A Classification System and Surgical Treatment Strategy. Ear Nose Throat J. 2006 May;85(5):328-31, 336. Laryngomalacia • Vast majority are mild • Parental reassurance & education o Transient worsening, gradual improvement o Weight gain issues o GERD issues- Consider GERD treatment if there is evidence on endoscopy Severe Laryngomalacia • Respiratory difficulty o Apnea/ Cyanosis/ ALTE • • • • • Feeding difficulty Failure to thrive Uncontrolled GERD Sleep apnea CNS abnormalities Severe Laryngomalacia Surgical Treatment • Supraglottoplasty- Aryepiglottic fold division +/- Excision of corniculate cartilages Severe Laryngomalacia Epiglottic Procedures • Epiglottic Procedures: o Epiglottoplasty- Excision of a V-shaped wedge of tissue from the epiglottis o Epiglottopexy- Epiglottis is pexied to the base of tongue with stitch/ laser Whymark AD, Clement WA, Kubba H, Geddes N. Laser Epiglottopexy for Laryngomalacia. Archives of Otolaryngology Head and Neck Surgery, 2006; 132: 978-982. Vocal Cord Paralysis • Bilateral: Airway issues, Aspiration issues o Expectant (can take years to resolve) o Close monitoring of O2 sat, apnea, weight gain o Tracheotomy o Posterior laryngeal expansion o Botox (for spastic paralysis) o Cordotomy o Arytenoidectomy o Re-innervation procedures • Unilateral: Voice Issues, Aspiration Issues o Observation o Vocal Cord Injection o Thyroplasty