Acute upper airway emergencies are common in children 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 factor, and an expanded knowledge of the most frequent airway problems encountered will assist in the proper evaluation, treatment, and disposition.

The small caliber of the upper airway in children results in greater airway resistance and makes it vulnerable to occlusion. Any process that further narrows the airway will cause an exponential rise in airway resistance and will increase 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 be corrective. Insertion of an orotracheal or a nasotracheal airway may alleviate respiratory distress. Older children will frequently present with enlarged tonsillar and adenoidal tissues. The child’s 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 of 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 oxygenation or ventilation.

Tachypnea represents the most common response of the child to increased respiratory needs. Although most commonly caused by hypoxia or 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 children. This includes 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 suprasternal, and supraclavicular retractions as well as nasal flaring are commonly seen.

Many infants and children with upper airway compromise will assume a “position of comfort,” which represents their optimal anatomic compensation for their disease state. Children with stridor will often assume an upright position, lean forward, and generate their own jaw thrust maneuver to facilitate opening of the upper airway. Those with upper airway compromise may also prefer to breathe through an open mouth, which suggests dysphagia with inability to swallow secretions, or the general presence of air hunger. This is in contrast to children with lower airway conditions, specifically those with reactive airway disease, who assume a “tripod position” consisting of upright posture, leaning forward, and support of the upper thorax by the use of extended arms.

Cyanosis, a sign of inadequate oxygenation, is ominous. Cyanosis of respiratory origin tends to be central rather than peripheral. A secondary effect of cyanosis is the development of a decreased level of consciousness. The most common symptoms and signs of hypoxemia include agitation, irritability, and failure to maintain feeding efforts in the young infant.

By far, the most reliable sign of respiratory failure in the infant or child is an ineffective respiratory effort and an altered level of consciousness. Auscultation of the chest may reveal decreased air entry, poor breath sounds, and bradypnea as the child progresses toward respiratory failure. Concomitant with hypoxemia in infants is the development of bradycardia. Although bradycardia may also be due to excessive vagal stimulation, hypoxemia should be ruled out in all such cases of respiratory distress.

Administer supplemental oxygen to any child with respiratory distress. Oxygen may be delivered in a variety of ways, including mask with or without rebreather apparatus, nasal prongs, face tent, or via an oxygen hood. Infants and children who feel threatened by the use of frightening equipment may be placed in the mother’s arms and receive oxygen by tubing alone (at maximal flow) or by inserting the end of the tubing in a cup.

Identifying source for the respiratory distress, particularly differentiating between upper and lower airway pathologies, is a critical early step of the evaluation and management of these patients. Two key signs are wheezes and respiratory rate. A wheeze indicates lower airway obstruction. Very rapid respiratory rates, 40 breaths per minute or greater, indicate that the respiratory distress is not due to an upper airway obstructive pathology. Use a standardized approach to the patient in mild to moderate distress. Provide supplemental oxygen; allow the child to assume a position of comfort and create a comfortable, non-threatening environment for both parent and child. Avoid any noxious stimulus, particularly unnecessary procedures. Also maintain normothermia and hydration. Assess the degree of respiratory distress at presentation and at appropriate intervals.

Stridor, the hallmark of upper airway compromise, results from the generation of inspiratory turbulence transmitted against a narrowed lumen (see Fig. 34-1). Stridor may originate anywhere in the upper airway from the anterior nares to the subglottic region; however, it is most commonly subglottic. In the young infant, stridor is most often the result of a congenital anomaly involving the tongue (macroglossia), larynx (laryngomalacia), and trachea (tracheomalacia). Congenital forms of stridor are typically chronic in their presentation.

In the emergency department (ED), the most common cause of acute upper airway obstruction is croup. Other causes include foreign-body obstruction, bacterial tracheitis, epiglottitis, peritonsillar abscess, and retropharyngeal abscess (Tables 34-1 and 34-2).

CROUP (VIRAL LARYNGOTRACHEOBRONCHITIS)

Laryngotracheobronchitis (croup) accounts for 90% of stridor with fever affecting children most commonly from 6 months to 3 years of age.^1–3 The subglottic region becomes edematous and inflamed with a fibrinous exudate. Viruses responsible for croup include parainfluenza types 1, 2, and 3 (most common); adenovirus; respiratory syncytial virus (RSV); and influenza. The seasonal predominance (fall and winter) is related to the epidemiology of respiratory viral disease.