A 21-month-old male presents to the emergency room with a several-day history of upper respiratory symptoms, progressing to hoarseness, inspiratory stridor, a “barking” cough, rhinorrhea, and a low-grade fever.
LARYNGOTRACHEOBRONCHITIS (SUBGLOTTIC CROUP)
Croup, which affects primarily children between the ages of 6 months and 3 years, is a viral-mediated inflammation that affects the subglottic tracheal mucosa and the tracheobronchial tree. The patient presents with symptoms of upper respiratory infection, including rhinorrhea, cough, sore throat, and low-grade fever for several days before developing symptoms of upper airway obstruction characterized by inspiratory stridor and a barky or seal-like cough. The symptoms may last from a few days to more than a week with varying degrees of severity, and may be worse at night in the supine position.
Croup’s etiologies are parainfluenza virus type 1 (the most common), parainfluenza virus types 2 and 3, influenza A and B, respiratory syncytial virus, Mycoplasma pneumonia, herpes simplex I, and adenovirus. Although it is a viral illness, some patients may acquire bacterial superinfection of their airway and require antibiotic therapy.
Management of croup consists of humidified air, either heated or cool mist. If symptoms are more severe, nebulized racemic epinephrine can reduce airway edema. Steroid administration is controversial, but may decrease the severity of the disease, decrease the need for tracheal intubation, or hasten improvement in the first 24 hours of illness.
Heliox may be used if other therapies do not provide adequate management. In severe cases of hypoxemia that do not respond to nebulized epinephrine and oxygen therapy, endotracheal intubation is required.
BACTERIAL TRACHEITIS (MEMBRANOUS CROUP)
Bacterial tracheitis (membranous croup) is a rare, potentially life-threatening disease affecting children in a wider range of ages, with the average being 5 years of age. Children present with a more toxic appearance than those with viral laryngotracheobronchitis. They present with stridor, a barking cough, and a temperature greater than 38.5°. An endoscopic exam reveals an inflamed and edematous tracheal wall with thick, tenacious, adherent secretions.
Management consists of initiation of broad-spectrum antibiotic therapy. This should change when cultures and sensitivities are known. An endotracheal tube (ETT) should be placed for frequent tracheal suctioning, with secretions decreasing in 3-5 days. The patient should be initially observed in the intensive care unit even if not intubated.
The major cause of postintubation croup is subglottic injury and edema associated with traumatic intubation, especially with an oversized ETT. The incidence of postintubation croup increases when there is no air leak around the ETT and the airway pressure exceeds 40 cm H2O. Other factors associated with postintubation croup may include traumatic or repeated intubation, “bucking” or coughing with the ETT in place, changing the head position, ...