Flaring: reflexive opening of nares during inspiration with airway obstruction Retractions: accessory muscle use manifest as inward collapse of chest wall as a result of high negative intrathoracic pressure from increased respiratory effort; supraclavicular, suprasternal, and subcostal retractions usually reflect upper airway obstruction, intercostal retractions reflect lower airway obstruction or disease but may be seen with severe upper airway obstruction Head bobbing: extension of head and neck during inhalation and flexion during exhalation, seen in neonates, young infants, reflects accessory muscle use Stertor: snoring with nasal congestion, adenotonsillar hypertrophy, neuromuscular weakness Gurgle: inspiratory and expiratory bubbling sounds caused by secretions in the oropharynx, trachea, or large bronchi Aphonia/dysphonia: vocal cord obstruction, dysfunction Muffled voice: oropharyngeal obstruction Hoarseness: laryngeal obstruction, dysfunction Barky cough: subglottic, tracheal obstruction Stridor: abnormal turbulence over airway obstruction; (i) inspiratory: quiet, high pitched from glottic, subglottic region; (ii) expiratory: loud, harsh from carina or below; and (iii) biphasic: loud, harsh from trachea Grunt: expiration against a closed glottis to maintain expiratory lung volume with lower airway, gastrointestinal process Tracheal deviation: shifting of trachea to nonaffected side of chest due to air, fluid space-occupying process on contralateral side Wheeze: continuous, musical; (i) obstructed bronchi, bronchioles—polyphonic (variable pitched, regional differences) expiratory as in asthma; (ii) obstructed central airway—monophonic (low pitched, same in all lung fields) expiratory ± inspiratory as with tracheal foreign body, tracheomalacia Crackles (rales): discontinuous, usually high pitched, inspiratory; moist, from thin secretions in (i) bronchi, bronchioles (medium rales), or (ii) alveoli (fine rales) Rhonchi (coarse rales): discontinuous, usually low pitched, inspiratory; moist or dry, from exudate, edema, inflammation of larger bronchi Pericardial friction rub: saw-like sound, inspiratory, expiratory between sternum and apex of heart due to pericardial inflammation, fluid Hamman crunch/sign: pericardial crackles synchronous with heart beat due to heart beating against pneumomediastinum, left-sided pneumothorax Bronchophony, egophony, whispered pectoriloquy: alterations in voice sounds as a result of lobar pneumonia, pleural effusion Tactile fremitus: vibration on percussion increased with consolidation, abscess, decreased/absent with bronchial obstruction, pleural cavity spaceoccupying lesion Percussion of the chest may reveal either hyperresonance, suggesting air trapping, or dullness, suggesting an area of consolidation, atelectasis, a mass in the lung or pleural space, or pleural fluid ( Table 71.8 ) Air trapping is suggested by depressed position of the diaphragm Diaphragmatic excursion can be accessed by measuring the difference between the level of dullness on percussion during full inspiration and full expiration Poor diaphragmatic excursion may reflect diaphragmatic dysfunction The remainder of the physical examination should concentrate on the neurologic, cardiac, gastrointestinal, renal, skin, metabolic/endocrine, and hematologic systems as potential source of respiratory distress Approach The approach to the child with respiratory distress ( Fig 71.1A,B ) begins with the assessment of airway patency, oxygenation and ventilation For patients in extremis, appropriate resuscitation as per Basic and Advanced Life Support guidelines, should be initiated immediately Patients in extremis ( Fig 71.1A ) also require rapid identification and emergent treatment of underlying conditions Etiologies of extremis due to trauma most commonly include airway obstruction, tension pneumothorax, flail chest, CNS depression and cardiac tamponade The most common causes of extremis in patients with no history of trauma are foreign body, infection, and anaphylaxis For patients with mild to moderate respiratory distress, the initial focus of the examination should be on the respiratory and cardiac systems Assessment begins with the observation of patient position, general appearance, work of breathing, and respiratory sounds that can be appreciated without a stethoscope This is followed by evaluation of oxygenation and ventilation, and auscultation to assess abnormal cardiopulmonary sounds The remainder of the examination is performed when the child is sufficiently stable to tolerate the examination All patients with respiratory distress should have their oxygenation tested immediately by pulse oximetry Capnography measures end-tidal carbon dioxide (EtCO2 ) and CO2 waveform as a rapid means of assessing ventilation and can help identify upper or lower airway obstruction Stridor, altered phonation, and/or dysphagia suggest partial airway obstruction Children with abnormal auscultatory findings (i.e., wheeze, rales, rhonchi, and/or asymmetric breath sounds) and fever are likely to have infectious etiologies (e.g., pneumonia or bronchiolitis) Patients can be further categorized on the basis of tachypnea ( Fig 71.1B ) Children with rapid respirations and fever may have pneumonia, even in the absence of rales; empyema, pulmonary embolism, and encephalitis are also important considerations Tachypnea without fever points to trauma, cardiac disease, metabolic disturbances, toxic ingestions, or exposures Febrile children without tachypnea may have apnea or bradypnea as late manifestations of CNS infection In afebrile patients, considerations include CNS depression, spinal cord injury, neuromuscular disease, and neonatal apnea Diagnostic tests should be performed selectively to evaluate for diagnoses suggested by history and physical examination ( Table 71.9 ) Laboratory tests can inform respiratory status and diagnosis Airway and chest radiographs can be helpful in determining the site and often the etiology of respiratory distress, and may provide insights into the likely clinical course Flexible nasopharyngoscopy can help identify some etiologies of upper airway obstruction, as indicated Ultrasound may also provide information on diagnosis, as well as guide the management ( Table 71.10 ) Pulmonary ultrasound can be used to evaluate for pneumonia, pleural effusion, pneumothorax, and hemothorax Cardiac ultrasound can be used to detect presence of a pericardial effusion and assess overall cardiac function As appropriate, ultrasound findings can then be confirmed with chest x-ray or formal echocardiogram For complete details on pulmonary and cardiac ultrasound technique and findings, please refer to Chapter 131 Ultrasound Treatment Regardless of the cause of respiratory distress, aggressive treatment must be initiated immediately to rapidly address airway patency, oxygenation and ventilation ( Table 71.6 ) In the alert patient, establish and maintain the position that maximizes respiratory function Every effort should be made to avoid agitating the child Supplemental oxygen can be administered using nasal cannula, high-flow nasal canula, and simple or nonrebreather mask Noninvasive positive pressure ventilation, in the form of CPAP or BPAP may be trialed to decrease work of breathing and improve respiratory status In the patient with decreased sensorium, positioning the airway by chin lift (contraindicated if neck injury is suspected) or jaw thrust may relieve soft tissue obstruction of the airway The oral cavity should be cleared of secretions, vomitus, blood, and visible foreign matter In the alert patient with suspected soft tissue obstruction of the airway, a nasopharyngeal airway may improve airway patency In an unconscious patient, an oropharyngeal airway can be placed to relieve obstruction Bag-valvemask ventilation should be initiated in apneic patients or those with ineffective respiratory efforts The child in whom airway patency and/or adequate ventilation and oxygenation cannot be established or maintained using noninvasive approaches, requires endotracheal intubation Indications for endotracheal intubation directly related to respiratory distress include airway obstruction, inability to handle secretions, and risk of aspiration, and respiratory failure Tension pneumo- or hemothorax and/or pericardial fluid causing tamponade must be decompressed immediately Ultrasound is increasingly being used in management of patients in respiratory distress, including to establish lung pathology, to confirm tracheal intubation, and to guide relevant procedures (e.g., thoracentesis, thoracostomy, pericardiocentesis) Adjunctive therapies that can help with respiratory distress include placement of a nasogastric tube to decompress a distended abdomen and full expansion of the lungs, addressing fever, and correcting metabolic derangements and/or drug or toxin intoxication