-------------------------------------------------------------------------------- TITLE: RESPIRATORY DISTRESS IN CHILDREN SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: November 4, 1992 RESIDENT PHYSICIAN: Jeff S. Chimenti, M.D. FACULTY: Amy R. Coffey, M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. -------------------------------------------------------------------------------- "This material was prepared by resident physicians in partial fulfillment of educational requirements established 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. General Considerations--Stridor and Respiratory Distress A. Definition of stridor = Audible result of turbulent airflow during inspiration, expiration, or both which is secondary to a structural or functional narrowing (partial obstruction) at some point between the oral cavity and distal bronchi B. Bernoulli's Principal = whenever a fluid (gas or liquid) flows over a surface, the pressure exerted on the surface decreases as the velocity of the fluid increases C. Stridor may or may not be associated with respiratory distress, and may emit from more than one site; Stridor always merits immediate investigation because its presence heralds a pathologic narrowing of the airway with the potential of complete respiratory obstruction D. Stertor = snoring--audible turbulent airflow caused by nasopharyngeal obstruction and decreased tone and patency of the nasopharynx and oropharynx E. Airway Zones 1. Supraglottic and supralaryngeal zone (including pharynx) a. Stridor occurs on inspiration because loosely supported tissues (ie.,corniculate and cuneiform cartilages, AE folds, epiglottis, hypopharynx) fall into laryngeal inlet on inspiration b. As airflow velocity increases during inspiration the walls collapse due to Bernoulli's principal c. During expiration the velocity decreases and the positive pressure of expiration opens the area of collapse 2. Extrathoracic tracheal zone (including glottis and subglottis) a. Stridor predominately biphasic (both inspiratory and expiratory) because of rigidity/fixation at this level (1) glottis--vocal ligament tightly supports vocal cords between thyroid and arytenoid cartilages (2) subglottis--rigidity from cricoid ring b. Inspiratory phase always more prominent due to greater airflow during inspiration--placing stethoscope over larynx brings out less prominent expiratory phase c. Nonfixed glottic lesions (ie., laryngocele, saccular cyst) may manifest with inspiratory stridor 3. Intrathoracic tracheal zone (including bronchi) a. Stridor is expiratory because positive pressures of expiratory forces within the chest wall narrow the airway b. more prolonged sonorous sound c. distal bronchial obstruction--wheeze F. Site of obstruction causing stridor must be in the airway but the lesion may be extrinsic and compress the soft, flaccid airway of children or intrinsic and narrow the airway lumen G. Airway dimensions in infant or child are small and only slight narrowing will produce stridor and airway obstruction; soft tissue of larynx is loosely attached and will enlarge at expense of airway H. Pathologic respiratory sounds 1. Musical--stridor, wheezes (harmonious frequency and pitch) 2. Nonmusical--rhonchi, rales (popping sounds) I. Respiratory distress--may be associated with stridor, restlessness, confusion/agitation, tachypnea, tachycardia, nasal alar flaring, suprasternal or intercostal retractions, use of accessory muscles of respiration, cyanosis J. Respiratory distress can occur without airway obstruction 1. Extrathoracic--intracranial bleed, large abdominal mass, neuromuscular disease 2. Intrathoracic--diaphragmatic abnormalities, cardiac abnormalities, hyaline membrane disease, pneumothorax/pneumomediastinum, pleural effusion, pneumonia, pulmonary cysts, bronchopulmonary dysplasia II.Airway Disorders A. Congenital Disorders --laryngeal anomalies are most frequent cause of congenital airway obstruction; onset of sx. often delayed until lesion grows or superimposed inflammatory process 1. Laryngomalacia a. most common congenital anomaly causing airway obstruction; 60% of laryngeal problems in infants b. symptoms may not appear until several weeks of age--inspiratory stridor, normal voice c. immaturity of cartilaginous framework of supraglottis--inspiratory effort precipitates indrawing of epiglottis and A-E folds; epiglottis is often omega shaped d. symptoms exacerbated: feeding, supine position, agitation, URI e. prone position relieves symptoms--epiglottis and A-E folds fall forward f. treatment--observation, placement in prone position with neck extended; rarely requires tracheotomy or surgical trimming or lasing of epiglottis, A-E folds, or arytenoid tissue g. prior to surgical intervention evaluate GER which may increase airway sx. h. surgical intervention: severe respiratory obstruction, feeding difficulties or failure to thrive i. usually resolves with growth at 6-18 months 2. Tracheomalacia a. cartilaginous weakness of tracheal rings resulting in tracheal collapse (A-P diameter) and widening of posterior wall b. expiratory stridor, difficulty expelling secretions (esp. with URI) beyond collapsed segment, recurrent lobar pneumonia c. Types: (1) primary--usually resolves in 1st year of life, severe cases require CPAP or tracheotomy to bypass obstruction or intubation with positive pressure ventilation] (2) secondary--following repair of T-E fistula, extrinsic compression (innominate artery or great vessel anomaly, bronchogenic cysts, teratoma, cystic hygroma, hemangioma) 3. Vocal cord paralysis a. second most common cause of congenital stridor; 10% of congenital laryngeal lesions b. Bilateral--vocal cords paramedian, normal voice, acute airway distress necessitating intubation or tracheotomy, usually due to CNS anomalies such as Arnold-Chiari malformation and hydrocephalus producing brain stem herniation and stretching of both vagus nerves c. Unilateral--more common, weak cry with increased stridor during stress or agitation, must investigate entire path of motor nerve from brain stem, through neck, into chest, and back up to larynx; frequently cardiac or great vessel abnormality d. Diagnosis: flexible laryngoscopy with spontaneous breathing e. Treatment: unilateral or bilateral paralysis may resolve spontaneously; tracheotomy for bilateral paralysis; delay definitive airway treatment 4. Subglottic hemangioma a. biphasic stridor worse with crying or straining as hemangioma becomes engorged with blood b. 85% present within 1st 6 months of life, usually between 1-3 months c. 50% have associated cutaneous hemangiomas d. Diagnosis: lateral soft tissue neck film--subglottic mass; endoscopy--sessile, firm, compressible, pink, red or bluish mass on one side of subglottis e. Most grow in size until 2 years and then involute f. Treatment: possible tracheotomy, steroids, laser excision 5. Congenital subglottic stenosis a. lumen less than 3.5 mm in newborn with no h/o endotracheal intubation or laryngeal trauma b. 3rd most common cause of congenital stridor; most common congenital laryngeal anomaly causing severe respiratory obstruction requiring tracheotomy c. biphasic stridor presenting in 1st few months of life; suspect with persistent or recurrent croup d. Diagnosis: AP soft tissue film of neck--funnel shaped narrowing; endoscopy--assess diameter of subglottis via calibration with bronchoscope e. Treatment: most outgrow their condition and require no treatment; selected patients require tracheotomy and/or cricoid split 6. Choanal Atresia a. Obliteration of posterior nasal aperture with atresia plate bony (90% of cases) or membranous b. most commonly unilateral; bilateral atresia recognized during neonatal period because newborn infants are obligate nose breathers until 6-8 weeks of life c. cyclical episodes of cyanosis relieved by crying is characteristic of bilateral atresia d. unilateral atresia recognized later in life due to unilateral nasal obstruction and rhinorrhea e. Diagnosis: lateral plain film with contrast instilled in nares, CT scan (procedure of choice) f. Treatment: neonatal period--oral airway or McGovern nipple; surgical repair--transnasal, transpalatal 7. Congenital Webs a. may occur at any level of larynx but 75% at glottic level b. represent failure of laryngeal embryogenesis with symptoms often present at birth c. stridor varies with extent of webbing, cry is weak or absent d. Treatment: surgical lysis of web 8. Other Disorders a. Craniofacial Anomalies--many function well during normal activities but experience OSA (1) micrognathia and glossoptosis--Pierre Robin, Treacher Collins syndromes (2) macroglossia--Down's syndrome, hypothyroidism, mucopolysaccharidoses, Beckwith-Wiedemann syndrome b. Compression of trachea or esophagus by aberrant great vessels or mediastinal masses--dysphagia, respiratory distress with feeding; MRI is procedure of choice; surgical correction should be performed at early age to prevent tracheomalacia c. Lingual thyroid--thyroid scan prior to removing base of tongue mass to rule out only functional thyroid tissue; thyroid supression is usually curative B. Inflammatory Disorders 1. Croup a. Acute laryngotracheobronchitis (LTB)--most common cause of stridor in children; symptoms primarily due to subglottic inflammation b. primarily viral etiology--parainfluenza and influenza types A and B most frequently; others include--RSV, adenovirus, Coxsackie virus A, ECHO virus, measles virus c. Age range = 6 months to 2 years; if less than 6 months with no history of intubation then consider congenital subglottic stenosis until proven otherwise d. onset of symptoms is gradual over a 1-3 day period and often associated with a URI; biphasic stridor with more prominent inspiratory phase, barking cough, low grade fever, variable degree of respiratory distress, comfortable lying on side or back e. If stridor at rest, retractions, restlessness, respiratory rate greater than 30 then hospital admission is mandatory f. AP soft tissue of neck--steeple sign (subglottic narrowing), normal leukocyte count with lymphocytosis g. Management: (1) adequate hydration, cool humidification through mist tent to keep ciliary activity functioning, supplemental oxygen (2) nebulized racemic epinephrine-- use requires hospital observation for possible rebound, 0.5 ml of 2.25% solution diluted in 2 ml saline solution; side effects include tachycardia, HTN, arrhythmia (use cautiously if h/o heart problems (3) steroids--controversial; may have more significant effect in spasmodic croup, dose 1 to 1.5 mg/kg to a max. dose of 30 mg (4) antibiotics--ampicillin or amoxicillin may be considered if sx. last more than 48 hrs. (5) airway intervention--required in 6-10 %, intubation used more commonly than tracheotomy, duration of intubation usually 3-5 days, cause for concern is placing tube through already narrowed subglottis and leading to subglottic stenosis-- intubation is last resort! h. Spasmodic croup (1) variant of viral croup with sudden onset usually during sleep associated with sudden respiratory distress (2) symptoms may be recurrent and most common age is 1-3 years (3) cold, humid air is helpful and sx. may resolve as quickly as they occur; steroids have been helpful 2. Supraglottitis (Epiglottitis) a. most commonly in ages 2-6 yrs. but may occur in children as young as 6 months or in adults b. organism usually Haemophilus influenzae type B, occasionally Staph aureus or group A B- hemolytic Strep c. inflammation affects epiglottis, A-E folds, and corniculate and cuneiform cartilages d. onset of symptoms is fairly rapid (less than 24 hrs.), most commonly in winter and spring, occurs much less common than croup e. usually toxic--elevated temperature, increased pulse and respiratory rate f. inspiratory stridor exacerbated by supine position or anything causing increased respiratory effort g. course of symptoms--sore throat, dysphagia, odynophagia, and mild inspiratory stridor progress rapidly to drooling and severe inspiratory stridor with a muffled but clear voice, supraclavicular/intercostal/substernal retractions; full manifestation--child sits erect with chin forward, neck hyperextended, tongue thrust forward, anxiety, increased exhaustion, drooling, and air hunger h. Management: (1) radiographs--soft tissue lateral of neck--used to confirm diagnosis only if child is in no distress and there is some question about the diagnosis; swelling and rounding of epiglottis with thickening of A-E folds (thumb print sign) (2) No instrumentation of oral cavity and oropharynx--no tongue blades (3) No IV line insertion or venipuncture until airway established (4) Securing the airway is always the first priority (5) Ideal sequence: suspect epiglottitis--immediately to OR--mask anesthesia--intubation--direct laryngoscopy for definitive diagnosis; once diagnosis is suspected then child should never be left alone (6) blood cultures positive in most patients (50-80%) --obtain once airway secured (7) supraglottis appears edematous, red, and mucosa may be ulcerated/desquamated--surface cultures should be obtained during DL (8) hospital setting and surgeons experience dictate whether intubation or tracheotomy is used for airway maintenance--if hospital is not equipped to handle a tenuous pediatric airway in ICU, then tracheotomy is best; otherwise intubation is preferred --adequate sedation must be maintained to prevent self extubation and limit laryngeal trauma, nasotracheal intubation preferred (9) antibiotics--begun after blood cultures and surface cultures of epiglottis obtained; cefuroxime and ampicillin recommended (10)duration of intubation usually 36-48 hours, when temperature and leukocyte count returns to normal extubation is usually possible; confirm normal epiglottis on endoscopy prior to extubation (11)household contacts--if there are any younger than 4 yrs., then the entire family receives rifampin prophylaxis (20mg/kg/day for 4 days to a maximum of 600 mg) and the ill child should be treated before returning home (12)preparation should be made for emergency tracheotomy if intubation is not possible; may be preferable to secure airway with pediatric bronchoscope and perform tracheotomy over the scope 3. Bacterial Tracheitis a. acute upper airway infection characterized by subglottic edema and purulent tracheal secretions b. clinical features--intermediate between croup and supraglottitis c. may develop as secondary bacterial infection following croup d. symptoms--croup-like stridor, barking cough, and hoarseness that progresses over 2-3 days, high grade fever, toxic e. Management: direct laryngoscopy for culture and toilet, securing airway with endotracheal tube and suctioning, many require tracheotomy, inspissated purulent secretions may require removal with foreign body forceps; antibiotics--cover Staph aureus (most frequent cause), H. influenzae type B, group A Strep, and Neisseria species 4. Other Disorders a. Peritonsillar abscess, parapharyngeal abscess, retropharyngeal abscess, Ludwig's angina b. Inflammatory nasal obstruction--infectious rhinitis, allergic rhinitis, vasomotor rhinitis, nasal polyposis, adenoid hypertrophy, sinusitis--usually do not cause respiratory distress except in neonates who are obligate nose breathers c. Oropharyngeal obstruction--tonsillar hypertrophy from acute or chronic inflammation and may have obstructive sleep apnea; mononucleosis, diphtheria d. Hereditary Angioneurotic Edema--deficiency of C1 esterase inhibitor leading to recurrent episodes of laryngeal edema; positive family or personal history e. Juvenile rheumatoid arthritis--cricoarytenoid joint fixation f. Acute bronchitis--productive sputum, coarse rhonchi; Tx.: cold, humid air, usually no antibiotics (adenovirus), avoid antihistamines and antitussives--coughing is important g. Bronchiolitis--inflammation of small bronchioles, expiratory wheezes, similar in presentation to asthma, usually caused by RSV (respiratory syncytial virus); Tx.: oxygen, humidification, fluid replacement, possible intubation with assisted ventilation C. Iatrogenic and Traumatic Disorders 1. Laryngeal obstruction a. Vocal cord paralysis (1) may occur following routine intubation due to pressure induced ischemia on the recurrent laryngeal nerve, dislocated arytenoid cartilage or posterior glottic scarring (2) also may occur secondary to intrathoracic or cervical procedures with recurrent laryngeal nerve injury (left nerve at greatest risk with intrathoracic cases) (3) bilateral cord paralysis necessitates tracheotomy-- arytenoidectomy may allow trach tube removal b. Endotracheal intubation (1) mechanical trauma--ulceration, granuloma formation, webs, stenoses, necrosis, infection (2) complications increased with multiple intubation attempts, tight fitting endotracheal tubes, concurrent respiratory tract infection, coughing with ETT in position, excessive motion with tube in place, intubation more than one hour (3) acquired subglottic stenosis--much increased by long term intubation, especially in neonates; virtually all require tracheotomy and surgical reconstruction 2. Nasal Obstruction a. Nasopharyngeal stenosis--fusion of tonsillar pillars and soft palate to posterior pharyngeal wall by scar tissue; due to T + A or UPPP (also syphilis, caustic burns, diptheria, or SLE) b. Rhinitis medicamentosa--topical nasal decongestants >1 week, often have prior nasal obstruction from septal deviation or polyps c. systemic medications--antihypertensives, beta blockers, antidepressants 3. Foreign Bodies a. inspiratory stridor if lodged in larynx or hypopharynx b. laryngeal foreign body may present with croupy cough, respiratory distress, hemoptysis, wheezing, and hoarseness c. tracheal foreign body may mimic croup d. radiography--plain films used to identify foreign body but it may be radiolucent; fluoroscopy and chest x-ray may identify air trapping, emphysema, or atelectasis; barium esophagram is no substitute for esophagoscopy and is not recommended as a primary diagnostic study e. esophageal foreign body may cause laryngeal or tracheal compression f. endoscopy should be performed without delay and rigid bronchoscopy and esophagoscopy is preferred g. uncontrolled attempts at removal (sweeping out pharynx, turning patient upside down, pounding between shoulder blades) should only be used in cases of complete airway obstruction 4. Blunt or Penetrating Trauma a. Mandible fracture--retrodisplacement of tongue b. Cervical trauma--arytenoid dislocation, hematoma or soft tissue swelling, laryngeal fracture c. Nasal obstruction--mid-face trauma with dislocation of nasal bones and septum; consider septal hematoma 5. Thermal or Chemical Trauma a. Massive mucosal edema following ingestion of acid, alkali or corrosive substances b. Inhalation of hot air, smoke, steam, or chemical fumes c. Careful observation because of possible rapid deterioration d. Therapy--fluids, mist, supplemental oxygen, racemic epinephrine, steroids, possible tracheotomy D. Neoplastic Disorders 1. Hemangioma a. most common head and neck neoplasm in children; mucosal hemangiomas can appear in nose, oral cavity, larynx, and pharynx b. often difficult to distinguish from exuberant granulation tissue arising from local trauma c. Septal hemangioma--anterior nasal septum; tx. is wide local excision with cuff of underlying mucosa and perichondrium d. Laryngeal hemangiomas (1) adult type--usually supraglottic and possibly reactive granulation tissue; excisional biopsy curative (2) infantile type--asymptomatic at birth with increasing stridor during 1st 3-6 months, stridor increases with crying or infection, hoarseness common, usually subglottic location, 50% have cutaneous hemangioms; endoscopy--unilateral, sessile compressible mass, between undersurface of TVC and lower cricoid border, discolored; radiographs--asymmetrical subglottic swelling; Tx. laser excision, systemic steroids, tracheotomy in severe cases 2. Juvenile Nasopharyngeal Angiofibroma (JNA) a. most common vascular tumor of nasal cavity b. age range is 7 to 21 years (peak 14-18) c. only occurs in males--if found in a female then question the diagnosis and consider chromosomal studies d. nasal obstruction, recurrent severe epistaxis, anosmia, respiratory compromise if advanced e. Diagnosis: carotid arteriography, CT scan for tumor extent f. slowly progressive enlargement, usually no reduction in tumor size as patient passes out if adolescence g. Tx. embolization and surgery, radiotherapy 3. Teratoma a. neoplasm with tissue elements from all three germinal layers b. nasopharyngeal teratoma--superior or lateral walls, dermoid cyst is most common teratoma in this site and presents as "hairy polyp", tx. is surgical excision, CT or MRI to determine extension preop and r/o glioma or encephalocele c. cervical teratoma--mass in neck found at birth, extrinsic compression with upper airway compromise, dysphagia from esophageal compression; immediate surgical resection 4. Lymphangioma (Cystic Hygroma) a. soft, compressible mass representing areas of regional lymphatic dilation b. 60% present by age 1, 90% present by age 3 c. dormant for long time and local infection may precipitate rapid growth d. most common location is posterior triangle of neck e. anterior triangle--may have pharyngeal compression and airway compromise from intraoral extension; laryngeal involvement may be a primary lymphangioma or extension from cervical site f. Tx. tracheotomy needed for laryngeal lymphangioma; surgical excision--complete but no compromise of normal structures, if gross tumor left then 50% recurrence rate 5. Recurrent Respiratory Papillomatosis a. laryngeal papillomas are most common laryngeal tumors in children, one third of cases present after adolescence, usually do not become symptomatic before 6 months, often associated with maternal venereal condylomata b. may be seen in any portion of upper aerodigestive tract c. Types: (1) "juvenile"--most common, multiple and recurrent despite therapy, spontaneous resolution may occur at puberty, otherwise a lifelong problem (2) "senile"--single, recurrence rare after removal, more friable when manipulated d. papilloma virus may simply initiate an abnormal tissue response (not true neoplasm) e. present with hoarseness and insidious airway obstruction (rarely may be sudden) f. Tx. microlaryngoscopy with laser excision, biopsy to r/o malignant degeneration, tracheotomy avoided at all cost because of increased tracheobronchial spread III. Evaluation and Management A. History 1. First always determine urgency of situation with cursory history --duration of respiratory distress (acute or chronic), progression of distress, possibility of foreign body ingestion 2. If airway distress is new and rapidly progressive with signs of agitation, cyanosis, or airway distress then airway intervention should be immediate without any further history or exam 3. Preparation for endoscopy/airway intervention should be made even if patient is stable 4. If airway distress is not acute with no evidence of progression then proceed with more detailed history and physical 5. Detailed history: a. age at onset (1) first 4-6 weeks--most likely laryngomalacia (2) birth--most likely vocal cord paralysis or choanal atresia (3) croup--unlikely before 6 months (4) adenotonsillar hypertrophy--usually 3-8 years (5) foreign body--most likely 1-3 years b. possibility of foreign body and its size and shape--immediate onset of stridor with choking spell c. fluctuations in stridor (1) worsens with airway demands like crying, agitation, feeding --laryngomalacia, subglottic hemangioma (2) worsens with sleep--adenotonsillar hypertrophy and laryngomalacia (3) improves with mouth open or crying--adenoid hypertrophy, choanal atresia, sinusitis (4) improves with sleep--vocal cord paralysis (5) improves when laying on one side and worsens when laying on the other--unilateral vocal cord paralysis, laryngocoele d. history of pregnancy, prematurity, and respiratory distress at delivery e. previous intubation (1) obstruction during first 3 weeks--laryngomalacia or congenital subglottic stenosis (2) obstruction between 1-3 months--subglottic hemangioma (3) stridor following extubation--subglottic edema or mucous plug (4) respiratory distress 2-3 weeks after extubation--subglottic stenosis or vocal cord granuloma (subglottic stenosis may not present for months) f. vocal changes (1) hoarseness--glottic pathology (2) muffled ("hot potato voice")--supraglottic or hypopharyngeal pathology (3) normal--subglottic or tracheal pathology g. history of trauma--blunt or penetrating h. history of congenital anomalies or craniofacial abnormalities i. family history of childhood respiratory distress or congenital/ craniofacial anomalies j. feeding difficulties with aspiration, reflux, regurgitation, cyanosis--impaired cricopharyngeal or esophageal musculature, abnormal laryngeal sphincteric function k. reflex apnea--respiratory arrests lasting several minutes and leading to cyanosis and unconsciousness (vascular rings) l. onset of stridor is gradual and progressive over weeks or months --neoplastic growth m. dysphagia and odynophagia--may indicate a supraglottic, hypopharyngeal, or esophageal lesion B. Physical Examination 1. Performed in nonthreatening manner with child in parents arms--do not agitate child! 2. Respiratory rate--measured with child at rest a. Tachypnea--anxiety, high fever, severe anemia, metabolic acidosis, respiratory alkalosis, pneumonia, pleural effusion, asthma, pulmonary edema b. Bradypnea--metabolic alkalosis, respiratory acidosis, CNS disorders 3. Respiratory rhythm--Cheyne-Stokes respiration (waxing and waning of depth of respiration with periods of apnea)--CHF, cerebral injury, increased intracranial pressure 4. Ease of respiration--orthopnea (easier sitting up), dyspnea (difficult in all positions) 5. Degree of respiratory distress--head movements with respiration (head bobbing), nasal alar flaring, circumoral pallor, intercostal or supraclavicular retractions, use of accessory neck and chest muscles, asymmetric inspiration (obstruction of one mainstem bronchus), fatigue 6. Agitation should be interpreted as sign of hypoxia and is treated with oxygen as 1st step--with improvement this should not be interpreted as adequate treatment but as stabilization prior to securing airway 7. Cyanosis--very late sign and one should never wait for its appearance before securing airway 8. Auscultation of chest and neck--locate site of greatest intensity by listening over nose, open mouth, neck, and chest; demonstrate subtle expiratory stridor, wheezes, rales, rhonchi, clicks 9. Pull mandible forward gently--if improvement then probably lesion in oral cavity or hypopharynx 10.Place in prone position with neck extended--decreases stridor of laryngomalacia, micrognathia, macroglossia, innominate artery compression 11.Tongue blade to examine oropharynx--do not if suspect supraglottitis 12.Palpation of neck and chest--crepitations suggesting tear of air passage; cysts or neck masses 13.Flexible fiberoptic laryngoscopy--perform only in stable patient --demonstrates nasopharyngeal, oropharyngeal, hypopharyngeal, supraglottic, glottic, and occasionally subglottic pathology; vocal cord mobility C. Radiography 1. With progressive airway distress do not delay securing airway; obtain X-rays only if patient stable 2. Radiography should be performed in ER if possible; if not then personnel and equipment capable of treating acute airway should accompany patient to radiology suite 3. Radiographs: a. AP and lateral of chest--inspiratory and expiratory to show segmental ventilation, foreign bodies, pulmonary disease b. AP and lateral of neck--inspiratory and expiratory films are especially important in infants because mobile pharyngeal soft tissues bulge on expiration c. Esophagram--R/O encrouchment by great vessel anomalies, swallowing difficulties, T-E fistulas d. Fluoroscopy--shows segmental ventilation e. CT scan--neck, lung, mediastinal masses f. MRI--procedure of choice for evaluation of tracheal compression D. Airway Management--Endoscopy 1. As soon as respiratory distress is established, patient should never be left unattended 2. Securing airway should take place in the safest area--operating room 3. Indications for immediate airway intervention: agitation, lethargy, cyanosis, significant respiratory distress--proceed immediately to the operating room 4. Ideal approach is with team of physicians--Otolaryngologist, Anesthesiologist, Pediatrician 5. Patient is transported with oxygen and mask for positive pressure as well as equipment and physicians for intubation 6. If airway is acutely compromised then one can buy time with positive pressure 7. If patient struggles with the mask and positive pressure then patient probably does not need them and best to blow by humidified oxygen; if positive pressure is helpful then patient will not resist mask and becomes quieter 8. Operating room is called about patient information and equipment necessary for intubation and endoscopy-- pediatric bronchoscopes, Benjamin laryngoscopes, and other appropriate endoscopy equipment is set up prior to patient entering room; tracheotomy equipment should also be available 9. Parents should remain in contact with child and if agitation occurs with separation from parents then they should accompany child into operating room 10. First task of surgeon is to check equipment for intubation and endoscopy--must insure proper set up 11. If airway worsens on reclining then induction should take place in sitting position 12. No IV lines are inserted and no blood gases or venipuncture are drawn before or during initial stages of induction 13. Once child starts to lose consciousness, parents should be escorted from OR 14. If airway becomes completely obstructed then person with the most experience should intubate 15. Induction: a. Inhalation techniques without nitrous oxide or muscle relaxants are preferred with respiratory distress b. preoxygenation is followed by rapid halothane and high oxygen concentration induction c. induction will be prolonged because of airway distress and decreased flow of O2 and anesthetic agent d. most frequent error is manipulating airway when anesthesia plane is not deep enough--increased chance of laryngospasm; airway should be manipulated only in deep plane, preferably apneic e. atropine is given before airway manipulation to decrease vagal response of bradycardia and decrease secretions; lidocaine may be applied topically to the larynx in children > 6 months f. airway is more difficult during stage II of induction--patience and positive pressure are key; airway much easier as patient enters deeper planes of anesthesia g. if airway cannot be managed and becomes obstructed--safest to intubate with rigid bronchoscope 16. Secure airway with bronchoscope or oral intubation--later change to nasotracheal tube (more stable); once airway secured then proceed with esophagoscopy, nasopharyngoscopy, bronchoscopy 17. Beware of possible foreign body on intubation 18. If tracheotomy is performed it should be done over a bronchoscope or endotracheal tube 19. Neonate--may elect to perform laryngoscopy without general anesthesia 20. Inspect vocal cord mobility with lighter anesthesia prior to or just after extubation (active bilateral movement) 21. Subglottic size determines bronchoscope size because this is the narrowest portion of the child airway: age bronchoscope size true external diameter(mm) premie-neonate 2.5 4.0 0-6 months 3.0 5.0 6-18 months 3.5 5.7 18-36 months 4.0 7.0 3-8 years 5.0 7.8 >8 years 6.0 8.2 IV. Pediatric Tracheotomy (Bluestone and Stool-Chapter 82) A. Indications 1. Should be evaluated on a patient to patient basis 2. General categories include: 1) airway obstruction; 2) assisted ventilation; 3) pulmonary toilet 3. Anterior cricoid split may be used as an alternative in patients who fail extubation B. Tracheotomy Tubes 1. Many types of tubes utilized--Shiley, Aberdeen, Holinger 2. Small children--noncuffed tubes, older children--low pressure cuff 3. Size of tube (outer diameter=OD) to be used is determined by visualizing tracheal lumen and comparing it to size of endotracheal tube or bronchoscope which is in place; Tables are also used for estimation of size based on age 4. Length of tube is also important so as not to abut against carina (Shiley neonatal is shorter than Shiley pediatric) C. Technique 1. Jackson's description (1921): "...it rests fundamentally on making two incisions, the first of which splits open the entire front of the neck from the 'Adam's apple' to the suprasternal notch; the second incision opening the trachea, which has been found by palpation with the left index finger in the pool of blood that fills the wound...the trachea being incised by sense of touch instead of sight. The two step, finger-guided operation does not require more than one minute... "-----DON'T DO THIS!!! 2. Procedure requires prior intubation with bronchoscope or endotracheal tube 3. Shoulders elevated on a roll with neck hyperextended and tape across forehead to maintain extension 4. Palpate neck--hyoid bone and cricoid cartilage are more prominent than thyroid cartilage in child; note that structures are soft and larynx is high; endotracheal tube or bronchoscope greatly facilitates accurate palpation of trachea 5. Skin incision 2 cm long and one finger breadth above sternal notch; horizontal vs. vertical incision is not a critical choice (scar from either is circular) 6. Young infants usually have large fat pad over the trachea and may need to remove a portion of this 7. Fascia beneath subcutaneous fat is grasped with hemostats, delivered into wound, and opened in midline with scissors 8. Finger inserted through wound and trachea palpated--procedure is done as much by palpation as by direct visualization (avoid carotid artery) 9. Layers of fascia and straps are successively incised in the midline and palpation is performed after each layer is incised (may need to remove retractors to palpate) 10.All layers should be incised flush with the wound edge so no funneling effect 11.If thyroid gland obscures trachea then elevate gland from trachea and divide in midline with bipolar cautery 12.Use stay suture in tracheal wall to deliver trachea into wound (3-0 or 4-0 silk placed 1-2 mm from midline) 13.Vertical incision through 3 to 4 tracheal rings 14.Tracheotomy tube is inserted with lateral traction on stay sutures to open up incision 15.With tube held in place, the shoulder roll is removed and chest is auscultated 16.No tight packing is used in wound--subcutaneous emphysema avoided 17.CXR performed prior to leaving OR to insure proper tube position ----------------------------------------------------------------------------- BIBLIOGRAPHY 1. Cummings, C.W., et al. Otolaryngology-Head and Neck Surgery, C.V. Mosby Company, 1986. 2. Bluestone, C.D. and Stool, S.E. Pediatric Otolaryngology, W.B. Saunders Company, 1990. 3. Benjamin, Bruce. Atlas of Paediatric Endoscopy: Upper Respiratory Tract and Esophagus, 1981. 4. Kairys, S.W., et al. Steroid treatment of laryngotracheitis: a meta-analysis of the evidence from randomized trials. Pediatrics 1989; 83:683. 5. Lee, K.J. Essential Otolaryngology, Medical Examination Publishing Company, 1991. 6. Ashcraft, C. and Steele, R. Epiglottitis--a pediatric emergency. Journal of Respiratory Disease. July 1988, 48-60. 7. Donaldson, J.D. and Maltby, C.C. Bacterial tracheitis in children. Journal of Otolaryngology 1989; 18:101. 8. Postma, D.S., et al. Severe hospitalized croup: treatment trends and prognosis, Laryngoscope 1984; 94:1170. --------------------------------END--------------------------------------------