Croup is rare in the first 6 months of life; stridor that presents in the first 6 months of life should instigate a search for other causes of the stridor. Congenital anomalies and subglottic hemangiomas should be considered in the differential diagnosis; these conditions narrow the airway and cause stridor in infants. The youngest reported child with croup was aged 3 months. http://emedicine.medscape.com/article/407964-overview
Degree of Confidence Airway radiographs detect croup with up to 93% sensitivity and 92% specificity. Note that subglottic haziness and the steeple sign can also be seen in a small percentage of children who have epiglottitis; however, additional radiographic findings that are specific for epiglottitis are present on the lateral radiograph. Subglottic narrowing from laryngotracheal hemangiomas is typically asymmetric. False Positives/Negatives A pseudo-steeple sign may be present in children without symptoms of croup. Other radiographic signs of obstruction are absent. Distention of the hypopharynx can be due to any condition that causes upper airway obstruction. Epiglottitis, foreign body aspiration or ingestion, subglottic hemangioma, or bacterial tracheitis all can create upper airway obstruction. Epiglottitis: Epiglottitis is associated with a distended hypopharynx and subglottic narrowing, but this condition also causes thickening of the epiglottis and aryepiglottic folds. Subglottic hemangioma: Subglottic hemangioma usually presents in the first 3 months of life. If the subglottic hemangioma extends superiorly to involve the true cords, hoarseness may be present in addition to stridor. Subglottic hemangiomas most commonly cause eccentric narrowing of the subglottic airway. Typically, croup causes symmetric subglottic narrowing. Membranous croup: In membranous croup, inflammation of the larynx, trachea, and bronchi, with an adherent or semi-adherent mucopurulent membrane in the subglottic space and upper trachea, is present. Radiographs of the airway show marked irregularity and edema of the walls of the trachea. A detached membrane may be seen in the lumen of the trachea and may be mistaken for a tracheal foreign body. If severe obstruction is present, endoscopic removal of the obstructing membrane may improve the clinical condition of the patient.
The long half-life of dexamethasone (54 h) often allows for a single injection.
A dose of 0.25 to 0.75 mL of 2.25% racemic epinephrine solution in 2.5 mL of normal saline can be given via nebulizer as often as every 20 minutes. If racemic epinephrine is not available, a 5-mL mixture of l-isomer epinephrine and saline (1:100) may be used. Corticosteriods decrease edema of the laryngeal mucosa via their anti-inflammatory action. After decades of debate about the potential benefits of systemic corticosteriods in children who have laryngotracheitis, there is now ample evidence to support their use. Clinical trials have demonstrated clear improvement in children who have viral laryngotracheitis of mild-to-moderate severity treated with oral or parenteral steroids compared with those who received placebo. Clinical improvement, however, is usually not apparent until 6 hours after initiation of treatment. Different doses and routes of administration for corticosteroids have been proposed. The beneficial effect of nebulized budesonide occurred more rapidly (2 to 4 h) than that seen with systemic steroids. This effect may be due to local vasoconstriction in the edematous laryngeal mucosa. Corticosteroids should not be administered to children with varicella or untreated tuberculosis. Prednisona 1 mg/kg PO q12h until 24 h after extubation; not to exceed 60 mg/24 h Nebulización con epinefrina: The effects of epinephrine are transient, and most trials show alleviation of symptoms for no longer than 2 h.
Epinefrina racemica: Administer 2.25% solution for nebulization (dose according to weight listed below) mixed with 3 mL saline:&lt;20 kg: 0.25 mL20-40 kg: 0.5 mL&gt;40 kg: 0.75 mLMay repeat q20-30min Epinefrina: 5 mL (5 mg) of 1:1000 solution diluted in 2 mL saline administered via nebulization; may repeat q20-30min
Media file 1: Normal lateral neck radiographs. During inspiration, the undersurface of the vocal cords is wide apart and not visualized. During phonation (saying &quot;e&quot;), the undersurface of the vocal cords are well visualized. The vocal cords, larynx, and lateral walls of the subglottic larynx and trachea are well depicted on the frontal view. The hypopharynx, epiglottis, aryepiglottic folds, prevertebral soft tissues, larynx, and subglottic airway can be evaluated on the lateral projection.
Media file 3: Lateral radiograph in a patient with croup. This image shows the presence of subglottic haziness and narrowing, as well as distention of the hypopharynx. The epiglottis and prevertebral soft tissues are normal.
Media file 5: Lateral radiograph in a patient with membranous croup (bacterial tracheitis). This image shows haziness in the subglottic region of the trachea. Soft-tissue defects are identified within the airway. The hypopharynx is overdistended.
Media file 6: Lateral radiograph in a 2-year-old child with stridor and fever. This image shows a swollen epiglottis and aryepiglottic folds that are typical of epiglottitis. The epiglottis contour resembles a thumb.
Media file 2: Normal anteroposterior radiograph of the neck. The normal convex borders (shoulders) of the vocal cords are outlined in the larynx.
Media file 4: Anteroposterior radiograph in a patient with croup. This image shows the steeple sign, with loss of the normal shoulders of the subglottic larynx.
CPHAP 028 Croup
DR. MANUEL UBIERGO GARCIA
Dra. María del Carmen Medrano
Jefe de Otorrinolaringología Pediátrica
Instituto Nacional de Pediatría
INFECCION QUE + CAUSA ESTRIDOR
OTOÑO E INVIERNO
> INCIDENCIA A LOS 2 AÑOS (6 m – 6 a)
◦ 5-6 CASOS POR 100 NIÑOS
INFLAMACION Y EDEMA DE LA REGION
SECRECION DE MOCO (Parainfluenza activa la
secreción de Cl e inhibe la absorción de Na)
COMIENZA CON SINTOMAS RESPIRATORIOS
DE 1 A 2 DIAS DESPUES:
DURACION DEL CUADRO 2-7 DIAS
◦ RX DE TORAX Y CERVICAL:
SIGNO DE “AGUJA”, QUE TRADUCE EN ESTRECHEZ
HIPOFARINGE DISTENDIDA DURANTE LA INSPIRACION
SIGNIFICATIVA EN SOLO EL 50% DE LOS CASOS
• Signo de la Aguja
• Signo del Reloj de Arena
• Steeple sign
TRANQUILIZAR AL NIÑO
EVITAR EL LLANTO
◦ INCREMENTA LA DEMANDA DE OXIGENO
◦ FATIGA DE LOS MUSCULOS RESPIRATORIOS
EFECTO ANTINFLAMATORIO: REDUCCION DEL EDEMA DE
LA MUCOSA FARINGEA
◦ ADRENALINA NEBULIZADA
ESTIMULACION ADRENERGICA: CONSTRICCION DE LA
ARTERIOLA PRECAPILAR, DISMINUYE LA PRESION
ESTIMULACION ß – 2- ADRENERGICA: RELAJACION DEL
MUSCULO LISO BRONQUIAL – BRONCODILATACION
EA: TAQUICARDIA, HIPERTENSION
O.15 – 0.6 mg/kg VO o IM en DU (No mas de 10 mg)
1 mg/kg VO
◦ BUDESONIDA (Pulmicort):
Nebulizaciones 2 ml (0.5 mg)
< 20 kg: 0.25 ml
20-40 kg: 0.5 ml
> 40 kg: 0.75 ml
◦ SE PUEDE REPETIR CADA 20-30 MIN
< DEL 5 % REQUIEREN HOSPITALIZACION
< DEL 2 % QUE SON HOSPITALIZADOS
FALLECEN 0.5 % DE LOS PACIENTES