croup dx,tx

7/28/2019 croup dx,tx

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a report by

Mario Canciani, MD, Matt ia Guerra, MD, and Ingr id Tol ler, MD

All ergology and Pul monolo gy Uni t, Dep art ment of Ped iat ric s, Dep art ment of Exper imenta l and Cli nic al Pat hol ogy and Med icine, Uni ver sit y o f U din e, Ita ly

CroupDiagnosis and Treatment

In ancient timesas well as throughout the first third of the 20th century

the term croup referred to the characteristic airway noise of patients

affected by diphtheria. Nowadays, croup is a broad, clinical diagnostic term

used for several respiratory illnesses that have varying degrees of inspiratory

stridor, hoarse voice, and harsh, barking cough.1 These symptoms are

thought to occur as a result of inflammation and edema of the upper

airway, including the larynx, trachea, and bronchi (hence the term

laryngotracheobronchitis), which, in the majority of cases, are triggered by

recent viral infection.2 The frightening nature of croup often prompts

parents and caregivers to consult a physician.

Epidemiology and Etiology

Croup is a common cause of upper-airway obstruction in young children,

occurring in about 2% of pre-school-age children annually.3 It mainly affects

children aged between six and 36 months, with a peak incidence at 1224

months. There is a male predominance of 3:2 and, although the disease can

occur throughout the year, it predominates in the fall and winter months.1 The

classification presented in Table 1 notes specific illnesses by etiology,

anatomical location, and clinical characteristics. Parainfluenza virus type 1

and influenza virus A are the agents most commonly identified in cases of

croup.4 Differentiating spasmodic croup from viral croup is difficult and

often not useful because the treatment does not differ.

Clinical Presentations

Signs and symptoms of croup are presented in Table 2; they get worse atnight and may peak on the second or third night. Determining the degree

of airway obstruction (based primarily on the history) is the most important

consideration when assessing children with croup. As airway obstruction

can worsen rapidly, repeated careful clinical assessment is essential.

Assessing Croup Severit y3

The following are important points in the assessment of croup severity:

General appearanceagitation, restlessness, irrational behavior,

hypotonia, and lethargy are clinical signs of severe obstruction.

Degree of respiratory distressstridor at rest, tracheal tug, intercostal

and subcostal indrawing on inspiration, tachypnea, or palpable pulsus

paradoxus indicate moderate to severe croup.

Cyanosis or extreme pallor indicates very severe obstruction.

Oxygen desaturation, indicated by oximetry, is usually a late and

unreliable sign of severity, and should never be a substitute for good

clinical assessment.

The loudness of the stridor is not a reliable indicator of the severity of croup.

Auscultation of the chest usually reveals only transmitted upper-airway

noise; breath sounds that are reduced in volume also indicate severe illness.

Diagnosis

The well-prepared clinician can often make a diagnosis based solely on the

history and physical examination, using radiographs and laboratory

examinations to aid in diagnosis when the clinical scenario is unclear.

Standard work-up for clinical diagnosis includes the assessment of skin

color, hydration, breath sounds, and air movement. X-ray examination is not

part of the standard assessment. Only 50% of patients with croup show

classic steeple signs on plain neck radiography (see Figure 1).5

Patients with atypical features in whom the diagnosis is unclear should have

a different work-up to exclude other less common entities such as

retropharyngeal abscess, epiglottitis, bacterial tracheitis, and foreign bodies.

This work-up may include: cell blood count and blood culture; soft-tissue

plain radiography of the neck; and computed tomography scan of the neck

with intravenous contrast.

The classical radiography signs are:

the thumb sign in the epiglottitis on the lateral airway neck film, due to

Respiratory

47 T O U C H B R I E F I N G S 2 0 0 7

Mario Canciani, MD, is Head of the Allergology and

Pulmonology Unit in the Department of Pediatrics, Department

of Experimental and Clinical Pathology and Medicine, University

of Udine, Italy.He is also Professor at the University of Trieste

and Udine Schools of Medicine. Professor Canciani is a Member

of the Italian Pediatric Society and the European Respiratory

Society, Secretary and then Chair of the Pediatric Respiratory

Infectious Disease and Immunology Group, and a Member of

the Website Committee and the Executive Committee of the

Italian Childhood Respiratory Society.

X-ray examination is not part of the

standard assessment. Only 50% of

patients with croup show classic steeple

signs on plain neck radiography.


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Respiratory

48U S P E D I A T R I C S R E V I E W 2 0 0 7

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edema of the epiglottis thickening the free edge (the posterior-anterior

radiograph is usually unremarkable); and

a widening of the retropharyngeal space, due to the abscess (see Figure 2).

Measuring at the level of C2, the normal distance from the anterior surface

of the vertebrae to the posterior border of the airway should be 7mm,

regardless of the patients age. A simpler (but less precise) rule is that the

soft-tissue plane should be less than half the width of the corresponding

vertebral body.6

Treatment

The most important aspect in the treatment of croup is airway maintenance;

standard management includes mist therapy, corticosteroids, and adrenalin.

Any child with croup and evidence of respiratory distress should be

considered a candidate for steroid treatment.1,3 Less frequently,

hospitalization and intubation are necessary. A clinical croup score

(according to the Westley croup score) should be recorded before and after

each treatment (see Table 3).

A score of 2, if there is some accessory muscle use/recessions and stridor

at rest, is considered to indicate moderate to severe airway obstruction and

requires oximetry and monitoring heart rate, and powering of the

treatment by oxygen.

Mist Therapy

Treatment with humidified air was previously widely used; theoretically, inspired

air that is cooler than body temperature and less than 100% saturated with

water vapor will result in mucosal cooling, vasoconstriction, and lessened

edema. Although this treatment has never been scientifically validated, it is still

recommended as a home treatment: parents should take the symptomatic

child into the bathroom while running a hot shower and filling the room with

warm water vapor.7,8 Warm steam may improve symptoms.

Steroids

The use of corticosteroids in patients with croup was controversial for

many years but, in the last decade, has transformed the management of

this illness. The results of a meta-analysis showed that steroids are effective

in improving symptoms of croup within six hours, for up to 12 hours, withsignificant improvement in scores of croup severity, shorter hospital stays,

reduced need for endotracheal intubation, and less use of adrenalin. 4,9

While it seems clear that steroids provide benefits, more recent studies

have tried to determine the optimal method of administration of the

treatment. The effectiveness of oral or intramuscular dexamethasone

(0.6mg/kg) as a treatment for patients with moderate to severe croup is

well established.10,11 Doses of dexamethasone ranging from 0.15mg/kg to

0.6mg/kg have been shown to be similarly efficacious for treating

moderate croup.12 Two recent studies suggested that the use of a single

dose of oral dexamethasone treatment for mild croup demonstrates more

Table 1: Comparison Of Upper-airway Obstructions

Laryngotracheobronchitis Spasmodic Croup Epiglottitis Inhaled Foreign Body

(Viral Croup)

Age range Six months to five years Six months to three years Two to seven years Newborn to adult

Etiology Parainfluenza viruses ?Viral Hemophilus influenzae Object small enough to fit in

Influenza A and B ?Airway reactivity Staphylococcus aureus (rarely) mouth or nares

Adenovirus

Respiratory syncytial virus

Onset Gradual Sudden Sudden Sudden

Clinical presentations Low-grade fever Afebrile High fever Afebrile

Non-septic Non-septic Septic Respiratory distress

Barking cough Barking cough Non-barking cough Choking

Stridor Stridor Muffled voice

Hoarseness Hoarseness Drooling

Dysphagia

Sitting forward with mouth open

Adapted from Custer, 1993.21

Table 2: Clinical Manifestations of Croup

1. Constitutional state (toxicity, fever, pulse rate)

2. Str idor

3. Drooling

4. Barking cough

5. Speech

6. Tachypnea

7. Tracheal tug on inspiration

8. Intercostal and subcostal indrawing on inspiration

9. Asynchrony of chest and abdominal wall movement

10. Cyanosis in air

Adapted from Custer, 1993.21

Table 3: Westley Croup Score

Stridor 0 None

1 When agitated or at rest, audible with stethoscope

2 At rest, audible without stethoscope

Retractions 0 None

1 Mild

2 Moderate

3 Severe

Air entry 0 Normal

1 Decreased but easily audible

2 Markedly decreased

Cyanosis 0 None

(sulphur dioxide 1 With agitation


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CroupDiagnosis and Treatment

49U S P E D I A T R I C S R E V I E W 2 0 0 7

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rapid symptom resolution, with important clinical and economical

benefits;11,13 for these reasons, oral steroids are currently preferred in most

pediatric emergency departments. Commonly used alternatives to

dexamethasone are prednisone or prednisolone (12mg/kg).14 The use of

nebulized budesonide (2mg) to treat patients with moderate croup has

been shown to be effective.15,16

A number of trials have shown that oral and intramuscular dexamethasone

and nebulized budesonide have the same effectiveness for treatment of

moderate croup and the choice depends on the status of the patient,

availability, and cost.17

Adrenalin

A child with persisting inspiratory stridor at rest and marked chest-wall

retractions should receive immediate treatment with nebulized L-adrenalin

(1:1,000 dilution at a dose of 0.5ml/kg to a maximum dose of 5ml). Inhaled

adrenalin has a rapid onset of action (30 minutes), has a temporary

beneficial effect on airway obstruction, and, although not a definitive

treatment, may allow time for the basic pathology to resolve.18 The L-isomer

of adrenalin alone is preferred to racemic adrenalin as it is safe, much less

expensive, and readily available worldwide.19

The association of a nebulized steroid (beclomethasone or budesonide)

improves the efficacy of L-adrenalin, since the steroid begins to work when

L-adrenalin decreases.20 Common adverse effects of L-adrenalin include

tachycardia and hypertension, so should be used with caution in patients

who have heart conditions or arrhythmias. As the effect of adrenalin is brief,

croup symptoms may reappear, demonstrating a rebound phenomenon;

children receiving adrenalin must be observed for a minimum of four hours

in the accident and emergency (A&E) department prior to discharge and

should only be discharged after the clinician is convinced that the parent

thoroughly understands the disease process and is able to return to the A&E

department expeditiously if stridor should recur.3

Hospitalization is indicated in children with increasing or persistent

respiratory distress, cyanosis, toxic-appearing, depressed sensorium, and in

young infants and patients with atypical symptoms.4

1. James D, State of the evidence for standard-of-care treatments for

croup: are we where we need to be?, Paediatr Infect Dis J,

2005;24:198202.

2. De Soto H, Epiglottitis and croup in airway obstruction in children,

Ane st hes iol Cli n Nor th Am , 1998;16:85368.

3. Fitzgerald DA, Kilham HA,Croup: assessment and evidence-basedmanagement, MJ A, 2003;179:3727.

4. Knutson D,Aring A,Viral croup,Am Fam Phy sic ian , 2004;69:

53540.

5. Malhotra A, Krilov LR,Viral croup, Pediatr Rev, 2001;22:512.

6. Philpott CM, Selvadurai D, Banerjee AR, Pediatric retropharyngeal

abscess, J Lar yng ol Oto l, 2004;118:91926.

7. Moore M, Little P, Humidified air inhalation for treating croup,

Cochrane Database Syst Rev, 2006;3:CD002870.

8. Scolnik D, Coates AL, Stephens D, et al., Controlled delivery of

high vs low humidity vs mist therapy for croup in emergency

departments: a randomized controlled trial,JAM A, 2006;296:

3934.

9. Fitzgerald DA,The assessment and management of croup, Paediatr

Respir Rev, 2006;7:7381.

10. Donaldson D, Poleski D, Knipple E, et al., Intramuscular versus oral

dexamethasone for the treatment of moderate-to-severe croup: a

randomized, double-blind trial, Aca d Eme rg Med, 2003;10:

1621.

11. Luria JW, Gonzalez-del-Rey JA, DiGiulio GA, et al., Effectiveness oforal or nebulized dexamethasone for children with mild croup,

Arc h Ped iat r Ado les c Med, 2001;155:134045.

12. Geelhoed GC, Macdonald WBG, Oral dexamethasone in the

treatment of croup: 0.15 mg/kg versus 0.3 mg/kg versus 0.6

mg/kg, Pediatr Pulmonol , 1995;20:3628.

13. Bjornson C, Klassen T, Williamson J, et al., A randomized trial of a

single dose of oral dexamethasone for mild croup, N Engl J Med,

2004;351:130613.

14. Tibballs J, Shann FA, Landau LI, Placebo-controlled trial of

prednisolone in children intubated for croup, Lancet,

1992;340:7458.

15. Klassen TP, Feldman ME, Watters LK, et al., Nebulized budesonide

for children with mild-to-moderate croup, N Engl J Med, 1994;331:

2859.

16. Fitzgerald DA, Mellis CM, Johnson M, et al., Nebulized budesonide

is as effective as nebulized adrenaline in moderately severe croup,

Pediatrics , 1996;97:7225.

17. Johnson DW, Jacobson S, Edney PC,et al., A comparison of

nebulized budesonide, intramuscular dexamethasone, and placebofor moderately severe croup, N Engl J Med, 1998;20:5535.

18. Wright RB, Pomerantz WJ, Luria JW, New approaches to

respiratory infections in children.Bronchiolitis and croup, Emerg

Med Clin North Am , 2002;20:93114.

19. Waisman Y, Klein BL, Boenning DA, et al., Prospective randomized

double-blind study comparing L-adrenalin and racemic adrenalin

aerosol in the treatment of laryngotracheitis (croup), Pediatrics,

1992;89:3026.

20. Canciani M, Marchi AG, Efficacy of L-epinephrine and

beclomethasone aerosol in croup, Eur Resp J, 1994;7:379.

21. Custer JR, Croup and related disorders, Pediatr Rev,

1993;14:1929.

F igu re 1: C la ss ic St eepl e S ig ns on Pl ai n N ec k R adi og raph y F igu re 2: R et ro ph ar yn geal A bs cess (a rro w)

The classic steeple sign of croup as shown on posterior-anterior neck radiography, resulting in a

narrowed column of subglottic air (top arrow) and an enlargement of the column (bottom arrow).

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croup dx,tx