Transcript Croup: Not all that barks is viral!

Croup
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Objectives
• Clarify the definition and epidemiology of
croup
• List the potential etiologic agents
• Know the signs and symptoms
• Differentiate croup from other causes of
inspiratory stridor and upper respiratory
disease
• Understand the management of croup
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Definitions
• Croup- term used to describe the clinical
picture of laryngotracheitis.
– Hoarse voice
– Barking cough
– Inspiratory stridor
– Possible respiratory distress
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Epidemiology
• Peak fall & winter.
• Range primarily 1-6 years
• Incidence 5/100 of children between age
1-2 years
• Males > females
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Etiologies
• Parainfluenza, types 1,2,3
– Contribute 65%-80% of cases.
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Influenza A & B
Adenovirus
RSV
Rarely mycoplasma.
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Pathogenesis
• Subglottic narrowing due to inflammation.
• Cricoid ring allows fixed area for
obstruction.
• 1mm swelling causes 65% obstruction in
infant.
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Pathogenesis
• Atelectasis/mucus plugging
• Ventilation/perfusion mismatch
• Negative intrapleural pressure may lead to
varying degrees of pulmonary edema.
• Hypoxia/hypercarbia
– Air hunger
– Anxiety/Lethargy/Obtundation.
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Clinical history
• Parents usually report viral URI symptoms
12-48hrs prior to cough.
• Fever, “Barking cough,”Stridor
• Typical course 3-5 days.
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Worry if
– Drooling
– Dyphagia
– Toxic appearance
– Stridor without cough or without fever
– Incomplete immunizations
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Badness mimicking croup
• Epiglottis
– Dysphagia
– Odynophagia
– Drooling
– Tripoding/sword-swallowing
• Pt resists lying on back
• Prefers leaning forward
– Stat to OR for evaluation/intubation
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Badness Mimicking Croup, cont.
• Bacterial tracheitis
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More common in order children to teens
Staph aureus/Diphtheria
Fever/ resp distress/Dysphagia/Odynophagia
Worsening over hours
Difficult to distinguish from epiglottis
Doesn’t matter, management is same:
• OR intubation
• Abx, worry more about Staph coverage if child is older.
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Badness Mimicking Croup, cont.
• Bacterial superinfection of Croup
– Symptoms 5-7 days
– Worsening quickly over hours
– Increasingly high fevers
– Toxic appearance
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Badness Mimicking Croup, cont.
• Retropharyngeal/peritonsilar abscess
– Fever
– Odynophagia
– Prodrome of sore throat
– Often swollen, tender ant. cerv. Nodes.
– Resistence to neck movement
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Badness Mimicking Croup, cont.
• Neoplasm
• Foreign body
– Afebrile
– Toddlers most at risk
– Often no history of aspiration
• Trauma
– History/physical exam.
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Badness Mimicking Croup, cont.
• Angioneurotic edema
– Recurrent
– Lip swelling
• Spasmotic croup (well, not really badness)
– Recurrent
– Nighttime
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Laboratory tests
• Little to no value…...
• ABG to assess for respiratory acidosis –
could worsen child’s symptoms by
stressing them
• May need IV access if in moderate to
severe distress
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Radiographic findings
• REMEMBER – CROUP IS A CLINICAL
DIAGNOSIS!!!
• Steeple sign on PA Film
• Lateral neck films if unsure of ruling out
retropharyngeal abscess
• Fluouroscopy if still unsure
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Anatomy
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Anatomy on X-ray
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Red -dilated hypopharynx
White - dilatation of the laryngeal ventricle
Blue - narrowing of the sub-glottic trachea
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Steeple Sign
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What is this?
Retropharyngeal Abscess!
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What is this?
Epiglottis
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Management of Croup
• Do I need an artificial airway!!!!
• Cool mist
– No literature to support efficacy
– Multiple studies demonstrating that it may
worsen situation (in moderate to severe
croup)
• Bronchospasm
• Hypothermia in young infants
• Tent obscures close observation of pt.
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Epinephrine
• Mechanism- constricts arterioles to airway thus
reducing further edema.
• Waiisman, et al. Prospective RCT comparing Lepi and RE in treatment of laryngotracheitis.
Pediatrics. 1992.
– Demonstrated reduced croup score by 30min, lasts
usually 2hrs.
– Dose 0.5cc of 2.25% racemic solution
– No difference found L- epi using 5cc of 1:1000 conc.
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Epi, cont.
• Rebound phenomenon
– Bunk… It just wears off in 2hours usually.
– Multiple studies demonstrating safe to d/c pt
from ER if:
• Steroids were given, too.
• No resting stridor 2-4 hrs after tx.
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Corticosteroids
• Steroid controversy…. getting clearer.
– Ausejo, M. Glucocorticoids for croup. Cochrane
Database of Systemic Reviews Jan 2000.
– Repeated with identical results by Moyer in
Pediatrics, March 2000.
• Metanalysis (N=2221 patients)
• Improved Croup score at 6 and 12 hrs, not 24 after
dexamethasone or budesonide neb.
• Decr. need for epi nebs by 9%.
• Decr. Emergency Room stay (-11hrs).
• Decr. Hospital stay (-16hrs).
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Corticosteroids, cont.
• Kairys, et al. Steroid treatment of
laryngotracheitis. Pediatrics. 1989.
– First meta-analysis of randomized trials.
– Demonstrated reduction in intubation from
1.27% (no steroids) to 0.17% steroids.
– No difference in inhaled budesonide versus
IM dex.
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Corticosteroids, cont
• Ritticher and Ledwith. Outpatient
treatment of moderate croup with
dexamethasone: Intramuscular versus
oral dosing. Pediatrics. 2000
– ER patients sent home.
– No statistical difference in later interventions.
– Power to detect at least 10% difference.
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Corticosteroids, cont.
• Klassen, et al. Nebulized budesonide and
oral dexamethasone treatment for croup.
JAMA. 1998
– Oral dexamethasone/Inhaled budesonide
– Both treatments
– No difference in groups
– Budesonide much more expensive.
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Corticosteroids
• A moment on dosage:
– Most studies 0.6mg/kg (IM or PO)
– Malhotra and Krilov. Viral Croup. PIR, 2001
• Lower doses of 0.15mg/kg and 0.3mg/kg shown to
be equally effective.
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Heliox
• Weber, JE. A randomized comparison of
Heliox and racemic epinephrine for the
treatment of moderate to severe croup.
Pediatrics. 2001
– N=29
– Similar improvement in both groups.
– No significant difference in croup score,
oxygen sat, respiratory rate or heart rate.
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Where to now?
• Still unanswered questions:
– Should you re-dose dexamethasone since the
duration is pharmacologically is 48hrs, but
benefit was only demonstrated though 12hrs?
– What about heliox and epi together?
– Should any patient with croup symptoms be
given steroids?
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