Acute respiratory emergencies in the pediatric patient are common and may, if improperly treated, result in significant morbidity and mortality.
The clinician must maintain an awareness of the unique anatomic and physiologic characteristics of the respiratory tract in the growing infant and child.
Stridor may originate anywhere in the upper airway from anterior nares to subglottic region.
The most common causes of acute upper airway obstruction are croup, epiglottitis, and foreign-body obstruction. Additional processes include peritonsillar abscess, bacterial tracheitis, and retropharyngeal abscess.
Acute upper airway emergencies are common in the pediatric patient and can result in significant morbidity and mortality. Calm, decisive, and deliberate intervention ensures the most effective outcome. Accurate assessment of the child in respiratory distress remains the most critical step in patient care and an expanded knowledge of the most frequent airway problems encountered will assist in the proper evaluation, treatment, and disposition of these patients.
The small caliber of the upper airway in children results in greater baseline airway resistance and makes it vulnerable to occlusion. Any process that further narrows the airway will cause an exponential rise in airway resistance and, as a result, will increase in the work of breathing. As the child perceives distress, an increase in respiratory effort augments turbulence and increases resistance to an even greater degree.
Since the young infant is primarily a nasal breather, any degree of nasopharyngeal obstruction may result in significant increase in work of breathing. The large tongue of infants and small children can occlude the oropharynx, especially with altered mental status and decreased muscle tone. Interventions such as tilting the head or lifting the chin may correct this effect. Insertion of an orotracheal or a nasotracheal airway may assist in alleviating respiratory distress. Older children will frequently present with enlarged tonsillar and adenoidal tissues. The pediatric trachea is easily compressible because of incomplete closure of the cartilaginous rings. Any maneuver that overextends the neck contributes to compression of this structure and secondary upper airway obstruction.
Abnormalities in respiratory function are eventually reflected in physical symptoms and signs ranging from subtle changes to obvious distress. Respiratory failure ensues when respiratory efforts cannot maintain adequate respiratory function, either oxygenation or ventilation.
Tachypnea represents the most common response of the child to increased respiratory needs. Although most commonly caused by hypoxia and hypercarbia, tachypnea may also be a secondary response to metabolic acidosis, pain, or central nervous system insult. Tachycardia represents a sign of distress of any etiology in the pediatric patient. This would include the patient with respiratory compromise.
Infants and children use accessory muscles as a compensatory mechanism to support the increased work of breathing. Intercostal, subcostal, sub- and supersternal, and supraclavicular retractions as well as nasal flaring are commonly seen.