Croup Treatment & Management

Urgent care or emergency department treatment of croup depends on the degree of respiratory distress. In mild croup, a child may present with only a croupy cough and may require nothing more than parental reassurance, given alertness, baseline minimal respiratory distress, proper oxygenation, and stable fluid status. The caregivers may only need education regarding the course of the disease and supportive homecare guidelines.

However, any infant/child who presents with significant respiratory distress/complaints with stridor at rest must have a thorough clinical evaluation to ensure the patency of the airway and maintenance of effective oxygenation and ventilation. In young children, it is important to keep the patient as comfortable as possible, allowing for him or her to remain in a parent's arms and avoiding unnecessary painful interventions that may cause agitation and increased oxygen requirements. Persistent crying increases oxygen demands, and respiratory muscle fatigue can worsen the obstruction.

Concurrently, careful monitoring of the heart rate (for tachycardia), respiratory rate (for tachypnea), respiratory mechanics (for sternal wall retractions), and pulse oximetry (for hypoxia) are important. Assessment of the patient’s hydration status, given the risk of increased insensible losses from fever and tachypnea, along with a history of decreased oral intake, is also crucial.

Infants and children with severe respiratory distress or compromise may require 100% oxygenation with ventilation support, initially with a bag-valve-mask device. If the airway and breathing require further maintenance due to worsening hypercarbia and respiratory fatigue, the patient should be intubated with an endotracheal tube. Intubation should be accomplished with an endotracheal tube that is 0.5-1 mm smaller than predicted. Once airway stabilization is achieved, these patients are transferred for their ongoing care to a pediatric intensive care unit.

The current cornerstones of treatment in the urgent care clinics or emergency departments are corticosteroids and nebulized epinephrine; steroids have proven beneficial in severe, moderate, and even mild croup.^[11] In the straightforward cases of croup, antibiotics are not prescribed, as the primary cause is viral. Lack of improvement or worsening of symptoms can be due to a secondary bacterial process, which would require the use of antimicrobials for treatment. Typically, these patients initially would have had moderate-to-severe croup scores, requiring inpatient care and observation.

Cool mist administration

Throughout the 19th and most of the 20th century, cool mist administration was the mainstay of treatment. Hospitals had "croup rooms" filled with cool mist. Theoretically, mist moistens airway secretions, decreases their viscosity, and soothes the inflamed mucosa. Animal data show that microaerosol inhalation activates mechanoreceptors that produce a reflex slowing of respiratory flow rate and leads to improved airflow.

However, despite its continued widespread use, little evidence supports the clinical efficacy of cool mist. Randomized studies of children with moderate-to-severe croup revealed no difference in outcome between those who received cool mist and those who did not.^[12] Mist tents, used in the hospital setting, can disperse fungus and molds if not properly cleaned and, more importantly, separates the child from the parent, causing anxiety and agitation, worsening the patient’s symptoms.^{[13, 14, 15]} In the home, vaporizers producing hot steam to humidify the air should not be used because of the risk of scalding or burns.

Corticosteroids are beneficial due to their anti-inflammatory action, whereby laryngeal mucosal edema is decreased. They also decrease the need for salvage nebulized epinephrine. Corticosteroids may be warranted even in those children who present with mild symptoms. (Corticosteroids should not be administered to children recently exposed to or diagnosed with varicella or tuberculosis due to the potential risk of exacerbating the disease process.)^{[16, 17, 18, 19, 20]}

A single dose of dexamethasone has been shown to be effective in reducing the overall severity of croup, if administered within the first 4-24 hours after the onset of illness. The long half-life of dexamethasone (36-54 h) often allows for a single injection or dose. Studies have shown that dexamethasone dosed at 0.15 mg/kg is as effective as 0.3 mg/kg or 0.6 mg/kg (with a maximum daily dose of 10 mg) in relieving the symptoms of mild-to-moderate croup. Despite this knowledge, clinicians still tend to favor the dose of 0.6 mg/kg for initial treatment of croup. Dexamethasone has shown the same efficacy if administered intravenously, intramuscularly, or orally.^[21]

Patients given a single oral dose of prednisolone (1 mg/kg) were found to have made more return visits than did those who received a single oral dose of dexamethasone (0.15 mg/kg).^[22] This is due to the lesser potency to reduce inflammation and shortened half-life of prednisolone (18-36 h) when compared with dexamethasone (36-54 h).

Inhaled budesonide has also proven to be effective but is more expensive; in one study, oral dexamethasone resulted in better improvement than did nebulized budesonide.

Nebulized racemic epinephrine is a 1:1 mixture of dextro (D) isomers and levo (L) isomers of epinephrine with the L form (L-epinephrine) as the active component. Its use is typically reserved for patients in the hospital setting with moderate-to-severe respiratory distress. Epinephrine works by adrenergic stimulation, which causes constriction of the precapillary arterioles, thereby decreasing capillary hydrostatic pressure. This leads to fluid resorption from the interstitium and improvement in the laryngeal mucosal edema.^[11] Epinephrine’s beta2-adrenergic activity leads to bronchial smooth muscle relaxation and bronchodilation. Its effectiveness is immediate and lasts from 90-120 minutes.

Patients who receive nebulized racemic epinephrine in the emergency department should be observed for at least 3 hours post last treatment because of concerns for a rebound phenomenon of bronchospasm, worsening respiratory distress, and/or persistent tachycardia. Patients can be discharged home only if they demonstrate healthy color, good air entry, baseline consciousness, and no stridor at rest and have received a dose of corticosteroids.

Heliox is a gas containing a mixture of helium and oxygen (with not less than 20% oxygen). Delivery to the patient is via nasal cannula, face mask, or hood. It has low viscosity and low specific gravity, which allows for greater laminar airflow through the respiratory tract. Helium decreases the force necessary and facilitates the movement of oxygen through the airways and decreases the mechanical work of respiratory muscles. This clinical response reduces respiratory distress.^{[23, 24]}

Several trials of heliox have demonstrated no advantage over conventional modalities; however, other trials have shown it to be equally effective in moderate to severe croup when compared with racemic epinephrine.^{[25, 26, 27]} Heliox has also been shown to improve symptoms in very severe croup that failed to improve with racemic epinephrine. Currently, the evidence is not sufficient to establish the effect of heliox in pediatric croup management.^[28]