-------------------------------------------------------------------------------- TITLE: STRIDOR IN NEONATE/INFANT EVALUATION AND MANAGEMENT SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: July 12, 1994 FACULTY: RONALD W. DESKIN, M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. -------------------------------------------------------------------------------- "This material was prepared for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. Stridor - Airway sound secondary to turbulent airflow - may be inspiratory, expiratory or combined. II. Pathophysiology Venturi principle Location Supraglottic - inspiratory Glottic/extrathoracic trachea - inspiratory and expiratory Intrathoracic trachea/bronchi - expiratory III. History Respiratory distress Duration Positional Association with feeding Voice Other congenital anomalies Trauma-? Foreign body-? IV. P.E. Observe - at rest and with agitation Voice Auscultation X-Ray AP/Lat. Chest/Neck Ba Swallow Fluoroscopy V. Endoscopy Flexible Rigid in OR VI. Conditions A. Supralaryngeal Adenoid hypertrophy Choanal atresia Reserpine (maternal) Cong. Lues Hypothyroid Nasal fracture Macroglossia Vallecula cyst Internal thyroglossal duct cyst Base of tongue tumor - thyroid, dermoid Retropharyngeal abscess Epulis Hemangioma, lymphangioma VII. Laryngeal/Subglottic Laryngomalacia Vocal cord paralysis - uni/bilateral Stenosis Web Atresia Hemangioma - 50% with cutaneous hemangioma Cleft of larynx Saccular cyst/laryngocele Papilloma VIII. Trachea Tracheomalacia Tracheal stenosis T-E fistula Extrinsic compression - vascular ring, esophageal foreign body Neonatal Respiratory Distress Due to Airway Abnormalities I. Introduction A. Respiratory distress in the neonate is a common occurrence and is usually due to pulmonary parenchymal diseases. Airway abnormalities occur much less frequently, but their presentation is often quite dramatic and significant respiratory distress may occur. B. The following anatomic classification outlines the broad spectrum of neonatal airway abnormalities likely to produce obstruction and respiratory distress. 1. Supraglottic a. Nose 1) Choanal atresia 2) Obstruction due to infection, trauma, tubes b. Craniofacial dysmorphology 1) Pierre Robin Syndrome 2) Treacher Collins Syndrome 3) Apert's 4) Crouzon's 5) Moebius Syndrome c. Macroglossia 1) Beckwith-Wiedemann Syndrome 2) Down's Syndrome d. Tumors 1) Hemangioma 2) Neuroblastoma e. Laryngomalacia 2. Glottic a. Vocal cord paralysis b. Tumors and cysts 1) Papillomatosis 2) Hemangioma 3) Cystic hygroma 4) Laryngoceles c. Atresia d. Webs e. Trauma 3. Subglottic a. Stenosis - congenital and acquired b. Webs c. Atresia d. Tumors 1) Hemangioma 2) Cystic hygroma 4. Trachea a. Tracheomalacia b. Stenosis c. Cyst d. Atresia 5. Extrinsic a. Goiter b. Vascular Ring c. Hemangioma d. Cystic hygroma e. Teratoma f. Mediastinal masses II. Pertinent Clinical Information A. History 1. Circumstances surrounding the onset of symptoms 2. Rapidity of progression of symptoms 3. Position of maximum comfort and effect of position change on symptoms 4. Presence of feeding abnormalities 5. Nature of cry 6. Previous infection 7. History of previous intubation or trauma 8. Presence of associated cardiopulmonary anomalies B. Physical Examination - be gentle 1. Subtle - restlessness, irritability, tachycardia, feeding difficulty 2. Overt - cyanosis, retractions, tachypnea, lethargy 3. Chest auscultation 4. Palpation of suprasternal and supraclavicular areas to determine position of trachea and presence of masses or crepitance 5. STRIDOR - the most important physical sign: Created by airway turbulence and indicates obstruction a. Inspiratory - implies supraglottic or glottic b. Expiratory - implies intrathoracic airway c. Mixed - implies subglottic III. Common Disorders of the Neonatal Airway A. Choanal Atresia 1. Obstruction in posterior nasal canal due to persistence of the buccopharyngeal membrane with associated excessive growth of the palatine bone. in 90% there is a bony septum while in 10% there is a mucosal diaphragm or membrane. 2. More common in girls. More common on the right side. Bilateral in 40%. Familial tendency - siblings have increased risks. Other congenital abnormalities (palatal abnormalities, coloboma, T-E fistula, congenital heart disease, Treacher-Collins Syndrome) occur in 50%. 3. Symptoms occur because babies are obligate nose breathers during first 3-6 weeks of life. a. Marked retractions and mouth breathing b. Coughing, choking, aspiration during feeding 4. Diagnosis a. Inability to pass catheter through nose b. Methylene blue instilled in nares does not enter pharynx c. Lateral x-ray after putting contrast into posterior nasal space d. CT scan e. Unilateral choanal atresia is frequently missed in the neonate and not diagnosed for months or years 5. Treatment a. Oral airway b. Close observation and constant monitoring c. Gavage feeds (possible gastrostomy) d. Tracheostomy - very rarely needed e. Repair of membranous atresia can be done early f. Repair of bony atresia can be done in a few weeks and requires stinting with plastic tubes post repair. Baby still needs close observation, monitoring, and most likely gavage feeding during this period. B. Pierre Robin Syndrome 1. Micrognathia, cleft palate, glossoptosis 2. Respiratory distress at rest or during feeding 3. Improvement in prone position or with nasopharyngeal airway. Rarely requires tracheostomy. 4. Improvement over 6-12 months due to mandibular growth C. Laryngomalacia 1. Etiology - excessively soft cartilage fails to provide sufficiently rigid framework for supraglottic and glottic structures. This results in inspiratory collapse of arytenoids, arytenoid folds, and epiglottis during inspiration, occluding the glottis. 2. Clinical Findings a. Inspiratory stridor which improves in prone position or at rest and increases with excitement or agitation b. Cry is unimpaired c. Maybe associated with feeding difficulties, failure to thrive, aspiration d. Onset at birth is unusual and generally is not evident for weeks to months. 3. Diagnosis a. Visualization of anterior collapse or arytenoids and aryepiglottic folds with epiglottis folding, on itself and collapsing posteriorly 4. Treatment a. Expectant. Cartilage matures over the first 6-12 months and symptoms resolve b. In extreme cases with failure to thrive and recurrent aspiration, gastrostomy or tracheostomy may be necessary c. Epiglottiplasty D. Vocal Cord Paralysis 1. Common causes (10%) of congenital airway obstruction. 80% unilateral. 2. Etiology a. Injury to vagus nerve at level of nucleus ambiguus - often bilateral b. Injury to left recurrent laryngeal nerve - cardiopulmonary and thoracic vascular anomalies c. Increased intracranial pressure - meningomyelocele with Arnold Chiari malformation 3. Clinical Findings a. Inspiratory stridor at birth b. Weak, hoarse cry or aphonia c. Decreased symptoms when placed on side of lesion (if unilateral) 4. Diagnosis a. Laryngoscopy - level of anesthesia must be light enough to allow spontaneous ventilation 5. Treatment a. Reduce intracranial pressure if present b. Expectant management c. Tracheostomy generally required for bilateral involvement E. Laryngeal Webs 1. Etiology - failure of laryngeal recanalization ranging from complete occlusion by mucosal and submucosal tissue to partial occlusion by a thin membranous web. May be supraglottic or subglottic for 75% occur at level of glottis 2. Rare - occur about 1 in 10,000 births 3. Clinical Findings a. Stridor (increased during inspiratory phase) present at birth b. Airway obstruction - degree depends on extent of the web c. Weak or absent cry because of cord fixation d. Not positional 4. Treatment a. Perforation may be life-saving b. Excision c. Dilation d. Cryotherapy e. Co2 Laser F. Subglottic Stenosis 1. Either congenital or acquired - most common cause of neonatal airway obstruction. Subglottic area is narrowest point in the neonatal/infant airway (glottic aperture is narrowest point in older child and adult). Area is susceptible to edema and inflammation and 1mm of edema reduces cross-sectional area by 1/3 2. Congenital is more common in males. Acquired is generally associated with prolonged intubation, repeated traumatic intubation, use of excessively large endotracheal tubes 3. Clinical findings - mixed inspiratory and expiratory stridor due to turbulence 4. Diagnosis - endoscopy 5. Treatment a. Tracheostomy b. Anterior cricoid division c. Resection - laser d. Dilatation e. Reconstruction G. Subglottic Hemangioma 1. Clinical signs a. Mixed stridor with normal voice or hoarseness if hemangioma abuts the under surface of the cords b. May be asymptomatic at birth but increasing symptoms as hemangioma grows - generally symptomatic by six months of age c. Subcutaneous hemangiomas are also present in about half the cases d. Croup - recurrent e. Ratio female to male = 2/1 2. Diagnosis a. Lateral cervical radiographs show eccentric swelling of subglottic region b. Endoscopy 3. Treatment a. Tracheostomy may be required b. Cryotherapy c. Excision d. Steroids e. Co2 Laser H. Tracheal Abnormalities 1. Tracheomalacia a. Pathophysiology and course similar to laryngomalacia b. Expiratory stridor due to collapse during expiration 2. Tracheal atresia and tracheal stenosis a. Often fatal shortly after birth b. Frequently associated with other congenital malformations 3. Vascular rings a. Compression of trachea and esophagus due to abnormalities in development of the great vessels including: 1) Right-sided aortic arch 2) Double aortic arch 3) Anomalous right subclavian artery 4) Aberrant left pulmonary artery b. Dyspnea present at birth with predominant (expiratory wheezing/expiratory stridor). Neck flexion exaggerates symptoms c. Diagnosis 1) Esophagram 2) Angiography 3) Tracheography 4) Echocardiography 5) Endoscopy -------------------------------------------------------------------------- BIBLIOGRAPHY 1. Cohen S., Geller K., Birns J., and Thompson J.: Laryngeal paralysis in children: a long-term retrospective study. Ann. Otol. Rhinol. Laryngol., 91, July-August, 1982. 2. Healy G.B., Fearon B., French R., and McGill T.: Treatment of subglottic hemangioma with the carbon dioxide laser. Laryngoscope, 90:809- 813, 1980. 3. Hollinger P., and Brown W.: Congenital web, cysts, laryngoceles and other anomalies of the larynx. Ann. Otol., 76:744-752, 1967. 4. McGill T., and Healy G.B.: Congenital and acquired lesions of the infant larynz. Clin. Pediatr., 17:584-589, 1978. 5. Bluestone & Stool, Pediatric Otolaryngology: W. B. Saunders Chapter 64.p.1190. 6. Richardson, Mark & Cotton, Robin: "Anatomic Abnormalities of the Pediatric Airway"; Pedi Clinics of North America, Vol. 31, #4, August 1984, p.821. --------------------------------END----------------------------------------