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1 Evaluation of the Airway A history and physical examination with specific reference to the airway should be performed in all children who require sedation or anesthesia. In particular, a history of a congenital or physical findings of congenital anomaly (e.g., microtia which has been associated with difficult laryngoscopy)[80] should alert the practitioner to the possibility of difficulties with management of the airway. In special situations, radiologic and laboratory studies are required to further evaluate and clarify a disorder revealed by the history and physical examination. Although many methods exist for evaluating and predicting the difficult airway in adults,[81 85] no published studies have assessed the use of any of these techniques in children.[86,][87] Routine evaluation of the airway in all children followed by correlation with any airway problems occurring during anesthetic management helps the practitioner to develop experience. This experience then may be used to identify future children who might have airway difficulties during or after anesthesia. Clinical Evaluation The medical history (both present and past) should investigate the signs and symptoms listed below; a positive history should alert the practitioner to the potential problems that are noted in parentheses (video clips are available on the website for some examples). Presence of an upper respiratory tract infection (predisposition to coughing, laryngospasm, broncho spasm, and desaturation during anesthesia or to post- subglottic edema or postoperative desaturation)[88 92] Snoring or noisy breathing (adenoidal hypertrophy, upper airway obstruction, obstructive sleep apnea, hypertension) Presence and nature of cough ( croupy cough may indicate subglottic stenosis or previous tracheoesophageal fistula repair; productive cough may indicate bronchitis or pneumonia; chronicity affects the differential diagnosis [e.g., the sudden onset of a persistent cough may indicate foreign-body aspiration]) Past episodes of croup (post- croup, subglottic stenosis) Inspiratory stridor, usually high pitched (subglottic narrowing [see Video Clip 12-1, Coming Soon], laryngomalacia [see Video Clip 12-1, Coming Soon], macroglossia, laryngeal web [Video Clip 12-2, Coming Soon], extrathoracic foreign body or extrathoracic tracheal compression) Hoarse voice (laryngitis, vocal cord palsy, papillomatosis [see Video Clip 12-1, Coming Soon], granuloma [see Video Clip 12-1, Coming Soon]) Asthma and bronchodilator (bronchospasm) Repeated pneumonias (incompetent larynx with aspiration, gastroesophageal reflux, cystic fibrosis, bronchiectasis, residual tracheoesophageal fistula, sequestration, immune suppression, congenital heart ) History of foreign-body aspiration (increased airway reactivity, airway obstruction, impaired neurologic function) History of aspiration (laryngeal edema [Video Clip 12-3, Coming Soon], laryngeal cleft [Video Clip 12-4, Coming Soon]) Previous anesthetic problems, particularly related to the airway (difficult, difficulty with mask ventilation, failed or problematic extubation) Atopy, allergy (increased airway reactivity) History of smoking by primary caregivers (increased airway resistance)[93] History of a congenital (many are associated with difficult airway management) The physical examination should include the following observations: Facial expression Presence or absence of nasal flaring Presence or absence of mouth breathing Color of mucous membranes Presence or absence of retractions (suprasternal, intercostal, subcostal [see Video Clip 12-1, Coming Soon]) Respiratory rate Presence or absence of voice change Mouth opening (Fig A) Size of mouth Size of tongue and its relationship to other pharyngeal structures (Mallampati)[84] Loose or missing teeth (Fig B) Size and configuration of palate Size and configuration of mandible Location of larynx in relation to the mandible (Fig C) Presence of stridor and if present: Is stridor predominantly inspiratory, suggesting an upper airway (extrathoracic) lesion (epiglottitis, croup, extrathoracic foreign body)? Is stridor both inspiratory and expiratory, suggesting an intrathoracic lesion (aspirated foreign body, vascular ring, or large esophageal foreign body)? (see Video Clip 12-1, Coming Soon) Is the expiratory phase prolonged or stridor predominantly expiratory, suggesting lower airway? Baseline oxygen saturation in room air Microtia: Bilateral but not unilateral microtia is associated with difficulty in visualizing the laryngeal inlet (Grade 3 or 4 Cormack and Lehane, see later). [80] Of those with bilateral microtia, 5 of 12 children (42%) had a difficult laryngeal view. However, even in the group with unilateral microtia, 2 of 81 children (2.5%) had a difficult laryngeal view compared with 0 of 93 children without microtia. Microtia may represent a mild form of hemifacial microsomia and its associated hypoplasia. The advantage of understanding this association is that ear deformity is often a more easily recognized clinical finding than hypoplasia. Global appearance: Are there congenital anomalies that may fit a recognizable? The finding of one anomaly mandates a search for others. If a congenital is diagnosed, specific anesthetic implications must be considered (see Appendix 12-1). 1 of 5 29/08/10 12:17 PM

2 Figure A, How far can a child open his or her mouth? Are there any abnormalities of the mouth, tongue, palate, mandible? B, Are any teeth loose or missing? C, Is the mandible of normal configuration? How much space is there between the genu of the mandible and the thyroid cartilage? This space is an indication of the extent of the superior and posterior displacement of the larynx; there should normally be at least one finger's breadth in a newborn and three finger's breadths in an adolescent. Appendix Syndromes and Disease Processes with Airway ies Achondroplasia[490]* [ ] Apert [499] Arthrogryposis multiplex congenita (multiple congenital contractures) [591] Beckwith-Wiedemann (visceromegaly)[ ] Cherubism (fibrous dysplasia of jaw)[506] Cornelia de Lange [493],[494] Midfacial small nasal passages and mouth narrow palate? cleft palate, Klippel-Feil, torticollis Macroglossia: regresses with age; may require partial glossectomy Bilateral painless and maxillary swelling may progress to airway obstruction High arch palate, micrognathia, spurs at anterior angle of large tongue,? cleft Megacephaly? hydrocephalus due to narrow foramen magnum Craniosynostosis,?CHD flat facies, hypertelorism? Mental handicap due to hypoglycemia? Hydronephrosis,? atresia? Esophageal polycystic kidney Dwarfism, Syndactyly?VSD Thoracolumbar scoliosis Large heart Enlarged kidneys Omphalocele, hepatosplenomegaly Hypoglycemia up to age 4 months polycythemia Eventration of diaphragm mask airway? hydrocephalus Possible difficult cardiac and renal problems Minimal muscle relaxant required? Malignant hyperthermia Asymptomatic hypoglycemia Omphalocele Neonatal polycythemia due to intraoral masses Mental handicap?chd cardiac 2 of 5 29/08/10 12:17 PM

3 palate, short neck Craniofacial dysostosis of Crouzon [499] Congenital hypothyroidism inverted V-shaped palate,? large tongue Large tongue Epidermolysis bullosa [541] Pressure lesions to mouth and airway Possible microstomia Freeman-Sheldon (whistling face)[ ] Goldenhar (oculoauriculo-vertebral )[487],[488] Marfan [ ] Hallermann-Streiff (oculomandibulodyscephaly)[498] Mucopolysaccharidoses[ ] Type IH (Hurler) [461] Type 1 H/S (Hurler- Scheie)[467] Type 1S (Scheie) or Type V[468] Type II (Hunter)[469] Small mouth, high palate Hypoplastic zygomatic arch, macrostomia,? cleft tongue, palate, tracheoesophageal fistula Malar micrognathia, hypoplasia of rami and anterior displacement of tempo ro joint, narrow high arch palate Narrow facies with narrow palate Ocular proptosis due to shallow orbits, craniosynostosis May be mentally handicapped Hypertelorism,? increased intracranial pressure,? mental deficiency,? microcephaly Coarse facial? Increased features, intracranial macroglossia, pressure short neck, tonsillar hypertrophy, narrowing of laryngeal inlet and tracheobronchial tree Macrocephaly, micrognathia Mandibular prognathism Hypothermia, Umbilical hernia hypometabolic Hydrocephalus Occipitalization of atlas, cervical vertebral defects Mild mental deficiency to normal intelligence Normal intelligence, corneal clouding Dissecting aneurysm, Severe coronary artery and valvular heart, cardiomyopathy? Valvular Aortic Coarse facial features; Increased intracranial Valvular heart, tracheomalacia, pressure; severe cardiomyopathy macrocephaly, mental deficiency Hepatosplenomegaly? Hepatosplenomegaly Hepatosplenomegaly Possible difficult Eye injury Hypothermia Decreased drug metabolism Need gentle with small tube. Postoperative laryngeal obstruction due to bulla formation Craniocarpotarsal? dysplasia, Malignant Strabismus, hyperthermia[ ] kyphoscoliosis, hip/knee contractures Scoliosis, kyphosis Joint stiffness, kyphosis, contractures, hypoplasia and subluxation defects cardiac and Postobstructive edema Mild joint stiffness? Joint stiffness Joint stiffness, dwarfism, kyphoscoliosis? 3 of 5 29/08/10 12:17 PM

4 macroglossia Type III (Sanfilippo) Mildly coarse Severe mental facial features deficiency Type IV (Morquio))[454], [455],[462] Nager [433] Papillomatosis of larynx and trachea[ ] Pierre Robin [ ] Mildly coarse facial features, prominent short neck Micrognathia, laryngoscopy Hypoplastic pseudomacroglossia;? high arched, Low-set ears, atresia of external auditory canal Late-onset r?gurgitation Pulmonary hypertension Joint laxity, kyphoscoliosis, Radial limb defects Pompe Large tongue Cardiomyopathy Muscle (cardiomuscular glycogen weakness storage )[470] Rheumatoid arthritis [ ] Rubinstein-Taybi Scleroderma[594] Smith-Lemli-Opitz [ ] Stevens-Johnson Thalassemia major (Cooley anemia)[595] Treacher Collins [ ] Tempo ro joint mobility limited, cricoarytenoid arthritis with narrow larynx narrow palate Extensive scarring of mouth, face, body Micrognathia?, recurrent pneumonia Laryngeal, tracheal, bronchial bullae, pneumothorax, pleural effusion Malar hypoplasia causes relative hypoplasia Malar,? cleft lip,? Myocarditis, valvular, especially Steroid, anemia subluxation, rigid cervical spine Mental handicap?chd cervical vertebral anomalies Moderate mental handicap, microcephaly Corticosteroid? Restrictive Take care not to seed papilloma into trachea Muscle weakness sensitive to muscle relaxants Congestive heart failure, sensitive to myocardial depressants heart Problems with positioning Corticosteroid Decreased compliance Steroid?CHD cardiac Myocarditis Urethritis Esophagitis, fluid shifts Temperature elevations Fluid balance Myocarditis Temperature control Avoid if possible Hemosiderosis May be difficult Anemia?CHD? deformity 4 of 5 29/08/10 12:17 PM

5 choanal atresia,? macro- or microstomia Trisomy 21 (Down Mental handicap AV communis, )[45],[442]* VSD, ASD [ ]*[ ] Turner (Noonan ) [491],[492] Small mouth, protruding tongue Narrow maxilla, Mental handicap small short neck Coarctation of aorta in females, artery coarctation in males Idiopathic hypertension Duodenal atresia Hypotonia, cervical spine subluxation Hypogonadism May be difficult Less muscle relaxant required Increased risk of post- stridor Hypertension ASD, atrial septal defect; AV, atrioventricular; CHD, congenital heart ; VSD, ventricular septal defect. Copyright 2010 Elsevier Inc. All rights reserved. Read our Terms and Conditions of Use and our Privacy Policy. For problems or suggestions concerning this service, please contact: online.help@elsevier.com 5 of 5 29/08/10 12:17 PM