Croup

Definitions
• Croup- term used to describe the clinical picture of laryngotracheitis.
l Hoarse voice
l Barking cough
l Inspiratory stridor
l Possible respiratory distress



Epidemiology
• Peak fall & winter.
• Range primarily 1-6 years
• Incidence 5/100 of children between age 1-2 years
• Males > females


Etiologies
• Parainfluenza, types 1,2,3
l Contribute 65% of cases.
• Influenza A & B
• Adenovirus
• RSV
• Rarely mycoplasma.


Pathogenesis
• Subglottic narrowing due to inflammation.
• Cricoid ring allows fixed area for obstruction.
• 1mm swelling causes 65% obstruction in infant.
• Atelectasis/mucus plugging
• Ventilation/perfusion mismatch
• Negative intrapleural pressure may lead to varying degrees of pulmonary edema.
• Hypoxia/hypercarbia
l Air hunger
l Anxiety/Lethargy/Obtundation.


Clinical history
• Parents usually report viral URI symptoms 12-48hrs prior to cough.
• Fever, “Barking cough,”Stridor
• Typical course 3-5 days.


Worry if

l Drooling
l Dyphagia
l Toxic appearance
l Stridor without cough or without fever
l Incomplete immunizations

Badness mimicking croup

• Epiglottis
l Dysphagia
l Odynophagia
l Drooling
l Tripoding/sword-swallowing
l Pt resists lying on back
l Prefers leaning forward
l Stat to OR for evaluation/intubation


• Bacterial tracheitis
l More common in order children to teens
l Staph aureus/Diphtheria
l Fever/ resp distress/Dysphagia/Odynophagia
l Worsening over hours
l Difficult to distinguish from epiglottis
l Doesn’t matter, management is same:
l OR intubation
l Abx, worry more about Staph coverage if child is older.


• Bacterial superinfection of Croup
l Symptoms 5-7 days
l Worsening quickly over hours
l Increasingly high fevers
l Toxic appearance



• Retropharyngeal/peritonsilar abscess
l Fever
l Odynophagia
l Prodrome of sore throat
l Often swollen, tender ant. cerv. Nodes.
l Resistence to neck movement

• Neoplasm
• Foreign body
l Afebrile
l Toddlers most at risk
l Often no history of aspiration
• Trauma
l History/physical exam.
Badness Mimicking Croup, cont.
• Angioneurotic edema
l Recurrent
l Lip swelling
• Spasmotic croup (well, not really badness)
l Recurrent
l Nighttime


Laboratory tests
• No value….. ‘nough said.

• Agitation for sticking child for ABG will worsen child’s symptoms.
• You still need IV access, though, sorry.


Radiographic findings
• Steeple sign
• Lateral neck films if unsure of ruling out retropharyngeal abscess
• Fluouroscopy if still unsure
• Still this is a clinical diagnosis
• If any airway worries, no radiographs
• Example radiograph…


Management of Croup
• Do I need an artificial airway!!!!
• Cool mist
l No literature to support efficacy
l Multiple studies demonstrating that it may worsen situation
l Bronchospasm
l Hypothermia in young infants
l Tent obscures close observation of pt.
Epinephrine
• Mechanism- constricts arterioles to airway thus reducing further edema.
• Waiisman, et al. Prospective RCT comparing L-epi and RE in treatment of laryngotracheitis. Pediatrics. 1992.
l Demonstrated reduced croup score by 30min, lasts usually 2hrs.
l Dose 0.5cc of 2.25% racemic solution
l No difference found L- epi using 5cc of 1:1000 conc.


• Rebound phenomenon
l Bunk… It just wears off in 2hours usually.
l Multiple studies demonstrating safe to d/c pt from ER if:
l Steroids were given, too.
l No resting stridor 2-4 hrs after tx.

Corticosteroids
• ‘Roid controversy…. getting clearer.
l Ausejo, M. Glucocorticoids for croup. Cochrane Database of Systemic Reviews Jan 2000.
l Repeated with identical results by Moyer in Pediatrics, March 2000.
l Metanalysis (N=2221 patients)
l Improved Croup score at 6 and 12 hrs, not 24 after dexamethasone or budesonide neb.
l Decr. need for epi nebs by 9%.
l Decr. Emergency Room stay (-11hrs).
l Decr. Hospital stay (-16hrs).



• Kairys, et al. Steroid treatment of laryngotracheitis. Pediatrics. 1989.
l First meta-analysis of randomized trials.
l Demonstrated reduction in intubation from 1.27% (no steroids) to 0.17% steroids.
l No difference in inhaled budesonide versus IM dex.

• Ritticher and Ledwith. Outpatient treatment of moderate croup with dexamethasone: Intramuscular versus oral dosing. Pediatrics. 2000
l ER patients sent home.
l No statistical difference in later interventions.
l Power to detect at least 10% difference.


• Klassen, et al. Nebulized budesonide and oral dexamethasone treatment for croup. JAMA. 1998
l Oral dexamethasone/Inhaled budesonide
l Both treatments
l No difference in groups
l Budesonide much more expensive.

• A moment on dosage:
l Most studies 0.6mg/kg (IM or PO)
l Malhotra and Krilov. Viral Croup. PIR, 2001
l Lower doses of 0.15mg/kg and 0.3mg/kg shown to be equally effective.


Heliox
• Weber, JE. A randomized comparison of Heliox and racemic epinephrine for the treatment of moderate to severe croup. Pediatrics. 2001
l N=29
l Similar improvement in both groups.
l No significant difference in croup score, oxygen sat, respiratory rate or heart rate.