Speaker : Dr. Wu Meng-Shu CROUP Speaker : Dr. Wu Meng-Shu

INTRODUCTION Croup is a respiratory illness characterized by inspiratory stridor, cough, and hoarseness. Inflammation in the larynx and subglottic airway. A barking cough is the hallmark of croup among infants and young children. Hoarseness predominates in older children and adults. Usually mild and self-limited. Significant upper airway obstruction, respiratory distress and, rarely, death, can occur.

Definition Laryngitis - hoarseness. Laryngotracheitis (croup) - lower airway signs are absent, the typical barking cough will be present. Laryngotracheobronchitis (LTB) - resulting in lower airway signs and sometimes more severe and bacterial superinfection. Bacterial tracheitis (also called bacterial croup) - resulting in a thick, purulent exudate, which causes symptoms of upper airway obstruction. Spasmodic croup - sudden onset of inspiratory stridor at night, short duration (several hours), and sudden cessation.

ETIOLOGY Parainfluenza virus type 1 - the most common, especially the fall and winter epidemics . RSV and adenoviruses Measles Influenza virus Rhinoviruses, enteroviruses Mycoplasma pneumoniae The most common secondary bacterial pathogens - Streptococcus pneumoniae, S. pyogenes, and Staphylococcus aureus.

EPIDEMIOLOGY Children 3 to 36 months of age, but is rare beyond age 6 years. More common in boys, with a male:female ratio of about 1.4:1. In the fall or early winter

PATHOGENESIS  The viruses that cause croup typically infect the nasal and pharyngeal mucosal epithelia initially, and then spread locally along the respiratory epithelium to the larynx and trachea. The anatomic hallmark of croup is narrowing of the trachea in the subglottic region. Dynamic obstruction

PATHOGENESIS Host factors include: Anatomic narrowing of the airway Hyperactive airways Acquired airway narrowing from respiratory tract papillomas (human papillomavirus) or post intubation scarring.

CLINICAL PRESENTATION-Laryngotracheitis Usually a gradual onset Beginning with nasal irritation, congestion, and coryza. Generally progress over 12 to 48 hours to include fever, hoarseness, barking cough, and stridor. Rapid progression or signs of lower airway involvement suggests a more serious illness. Symptoms typically persist for three to seven days with a gradual return to normal. Agitation, which generally is accompanied by increased inspiratory effort, exacerbates the subglottic narrowing by creating negative pressure in the airway.

Rapid Assessment General appearance (including the presence of stridor at rest) Vital signs Pulse oximetry Airway stability Mental status

Respiratory Failure Fatigue and listlessness Marked retractions Decreased or absent breath sounds Depressed level of consciousness Tachycardia out of proportion to fever Cyanosis or pallor A tracheal tube that is 0.5 to 1 mm smaller than would typically be used may be required. Immediate pharmacologic treatment, including administration of nebulized epinephrine and systemic or nebulized corticosteroids.

History Sudden onset of symptoms Rapidly progressing symptoms Previous episodes of croup Underlying abnormality of the upper airway Medical conditions that predispose to respiratory failure (eg, neuromuscular disorders) Fever Hoarseness and barking cough Difficulty swallowing Drooling

Physical Examination Overall appearance Quality of the voice — A muffled "hot potato" voice is suggestive of epiglottitis, retropharyngeal abscess, or peritonsillar abscess. Degree of respiratory distress Tidal volume — Does there appear to be good chest expansion with inspiration, indicating adequate air entry? Lung examination Assessment of hydration status

Physical Examination Cherry red, swollen epiglottis, suggestive of epiglottitis Pharyngitis, typically minimal in laryngotracheitis, may be more pronounced in epiglottitis or laryngitis Excessive salivation, suggestive of acute epiglottitis, peritonsillar abscess, or retropharyngeal abscess Diphtheritic membrane Tonsillar asymmetry or deviation of the uvula suggestive of peritonsillar abscess Midline or unilateral swelling of the posterior pharyngeal wall suggestive of retropharyngeal abscess

Severity Assessment — Westley croup score Level of consciousness: Normal, including sleep = 0; disoriented = 5 Cyanosis: None = 0; with agitation = 4; at rest = 5 Stridor: None = 0; with agitation = 1; at rest = 2 Air entry: Normal = 0; decreased = 1; markedly decreased = 2 Retractions: None = 0; mild = 1; moderate = 2; severe = 3 Mild croup is defined by a Westley croup score of 2. Moderate croup is defined by a Westley croup score of 3 to 7. Severe croup is defined by a Westley croup score of 8.

DIFFERENTIAL DIAGNOSIS Acute epiglottitis Peritonsillar and retropharyngeal abscesses Foreign body aspiration or ingestion Acute angioneurotic edema Upper airway injury Congenital anomalies of the upper airway

Imaging - Steeple sign

Croup lateral neck radiograph

Epiglottitis

Bacterial tracheitis

Home Triage Stridor at rest An abnormal airway Previous episodes of moderate to severe croup Medical conditions that predispose to respiratory failure (eg, neuromuscular disorders) Rapid progression of symptoms (less than 12 hours of illness) Inability to tolerate oral fluids Parental concern that cannot be relieved by reassurance Prolonged symptoms (more than three to seven days) or an atypical course (perhaps indicating an alternative diagnosis)

Mild Croup & Home Treatment Be treated symptomatically with humidity, fever reduction, and oral fluids. Running hot water from the shower or exposure to cold night air A follow-up phone call: Difficulty breathing Pallor or cyanosis Severe coughing spells Drooling or difficulty swallowing Fatigue Worsening course Fever (>38.5ºC) Prolonged symptoms (longer than seven days) Stridor at rest Suprasternal retractions

Mild Croup & Out-patient Tx May have improvement with humidified air. A single dose of oral dexamethasone (0.15 to 0.6 mg/kg, maximum dose 10 mg) may reduce the need for reevaluation, shorten the course, improve duration of the child's sleep, and reduce parental stress. An anticipatory guidance

Moderate To Severe Croup Administration of humidified air or humidified oxygen Nebulized epinephrine Any increase in anxiety may worsen airway obstruction BMV and advanced airway techniques if the condition worsens Monitoring respiration and consciousness Fluids Intubation - A tracheal tube that is 0.5 to 1 mm smaller than would typically be used may be required.

Moderate To Severe Croup Dexamethasone (0.6 mg/kg, maximum of 10 mg), by the least invasive route possible : oral or IV. Repeat doses of corticosteroids are not necessary on a routine basis. Nebulized budesonide (2 mg [2 mL solution] via nebulizer) - an alternative Nebulized epinephrine - Racemic epinephrine as 0.05 mL/kg per dose (maximum of 0.5 mL) of a 2.25 percent solution diluted to 3 mL total volume with normal saline. Observation - at least 3-4 hours

Discharge to Home Criteria No stridor at rest Normal pulse oximetry Good air exchange Normal color Normal level of conscious Demonstrated ability to tolerate fluids by mouth Caregivers understand the indications for return to care and would be able to return if necessary Before discharge, follow-up with the primary care provider should be arranged within the next 24 hours. Instructions regarding home treatment should be provided.

Hospitalization Need for supplemental oxygen Moderate retractions and tachypnea, indicating increased work of breathing, which may lead to respiratory fatigue and failure Degree of response to initial therapies "Toxicity" or clinical picture suggesting serious secondary bacterial infection Poor oral intake and degree of dehydration Young age, particularly younger than 6 months Ability of the family to comprehend the instructions regarding recognition of features that indicate the need to return for care Ability of the family to return for care (eg, distance from home to care site, weather/travel conditions) Recurrent visits to the ED within 24 hours

Prognosis Symptoms of croup resolve in most children within three days, but may persist for up to one week. Mortality is rare, occurring in <0.5 percent of intubated children.

Complications Uncommon: Hypoxemia and respiratory failure. Pulmonary edema Pneumothorax Pneumomediastinum

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