Peds in a Pod: So What's the Deal With Bronchiolitis?

HELP!!! This baby is wheezing

We’ve all been there. That shift when a parent walks in with their 4 month old wheezing for the first time. It’s that time when it seems like every child has a URI and is wheezing. You begin to wonder which treatment is best. Do you try some albuterol? Are steroids any good? Can this kid go home? Here we will talk about the evidence behind the treatment for bronchiolitis.

Bronchiolitis is the most common lower respiratory infection in infants and children up to 2 years of age and it is the leading cause of hospitalization in infants. It is characterized by inflammation, edema with necrosis of the epithelial cells lining the bronchioles and increased mucus production. Hypoxia is due to the ventilation/perfusion mismatch caused by decreased ventilation of a portion of the lungs. Diagnosis is indeed made with history and physical as there is no lab value that is useful.

It is absolutely important that emergency clinicians inquire about the patient’s risk factors for severe bronchiolitis, which is characterized by persistently increased respiratory effort, apnea, and the need for intravenous hydration, supplemental oxygen, or mechanical ventilation.

Risk Factors For Severe Bronchiolitis And Apnea

Risk factors for severe bronchiolitis:

1. History:

• Age: < 6-12 weeks

• Prematurity: < 34-37 weeks’ gestation

• Underlying respiratory illness such as CLD or BPD4

• Significant congenital heart disease, immune deficiency including human immunodeficiency virus, organ or bone marrow transplants, or congenital immune deficiencies

2. Physical examination:

• General appearance: ill appearing

• Oxygen saturation level: < 94% on room air

• Respiratory rate: > 70 breaths per minute or higher than normal rate for patient age

• Increased work of breathing: moderate to severe retractions and/or accessory muscle use

Risk factors for apnea:

• Full-term birth and < 1 month of age

• Preterm birth (< 37 weeks’ gestation) and age < 2 months post conception

• History of apnea of prematurity

• Emergency department presentation with apnea

• Apnea witnessed by a caregiver

Treatment

1) Nasal Suctioning- No RCTs but makes sense and will probably help if there is a lot of mucus/secretions in the nares especially for infants that are nasal breathers.

2) Supplemental O2- Should be used in pt’s with a pulse ox reading <90%.

3) Bronchodilators- This continues to be a controversial area. There have been numerous trials and evidence based systematic reviews but no consensus. The AAP’s Subcommittee on the Diagnosis and Management of Bronchiolitis recommends “a carefully monitored trial of adrenergic medication as an option and that inhaled bronchodilators should be continued only if there is a documented positive clinical response to the trial using an objective means of evaluation” A recent Cochrane review of bronchodilators other than epinephrine found that the agents produce small, short-term improvements but do not affect rate of hospitalization or length of hospital stay.

4) AnticholingergicsàIpatropium- A 2005 Cochrane review of the role of anticholinergic agents in the treatment of children younger than 2 years with wheezing identified 6 trials, only 2 of which involved patients with first-time wheezing. Compared with beta2-agonist alone, the combination of ipratropium bromide and beta2-agonist was not associated with a difference in treatment response, respiratory rate, or oxygen saturation improvement in the ED. There was no significant difference in length of hospital stay between the ipratropium bromide and placebo groups or between patients receiving ipratropium bromide and a beta2-agonist combined and those receiving a beta2-agonist alone. At this point, use of anticholinergic agents―either alone or in combination with beta-adrenergic agents―for viral bronchiolitis is not justified in the ED.

5) Epinephrine- A Cochrane review of inhaled epinephrine found no reduction in admission rates in the treatment racemic epinephrine group, with some studies demonstrating short-term improvements in clinical scores, oxygen saturation levels, and respiratory rates.

6) Steroids -A Cochrane Collaboration review of 13 studies on the use of corticosteroids for bronchiolitis showed no significant differences between corticosteroid and placebo treatment groups in respiratory rates, oxygen saturation levels, initial admission rates, length of stay, subsequent visits, or readmission rates.

Schuh and colleagues conducted a placebo-controlled trial involving 70 infants with moderate-to-severe bronchiolitis.82 The authors found significant reductions in respiratory scores after 4 hours of observation in infants who received oral dexamethasone 1 mg/kg and 0.6 mg/kg (which was continued for patients discharged home for 5 days) compared with those who received placebo. Moreover, the admission rate was 19% in the dexamethasone group compared with 44% in the placebo group.82 The limitations of this study are the small sample size and the larger proportion of positive family history of atopy in infants in the dexamthasone group (increasing the risk of having asthma) compared to those in the placebo group. This could have affected the impact of corticosteroids on the course of their illness in the dexamethsone group.
Inhaled steroids- Two available studies that evaluated use of inhaled corticosteroids in the treatment of bronchiolitis showed no benefit in the course of the acute disease. Unless there is a clear likelihood of benefit, high-dose inhaled corticosteroids should not be used in infants because of safety concerns.

7) Combo of Dexamethasone and Epi- Pediatric Emergency ResearchCanadaconducted a double-blind, placebo-controlled multicenter trial involving 800 infants (6 weeks to 12 months of age) with bronchiolitis at 8 Canadian pediatric EDs. Patients were randomly assigned to 1 of 4 study groups: (1) the epinephrine-dexamethasone group received 2 treatments of nebulized epinephrine and a total of 6 oral doses of dexamethasone (1.0 mg/kg in the ED and 0.6 mg/kg for an additional 5 days), (2) the epinephrine group received nebulized epinephrine and oral placebo, (3) the dexamethasone group received nebulized placebo and oral dexamethasone, and (4) the placebo group received nebulized placebo and oral placebo. The primary outcome was hospital admission within 7 days after the ED visit. Of interest, the epinephrine-dexamethasone group had a lower admission rate over 7 days than the placebo group (17.1% vs 26.4%, respectively). The study authors did not anticipate this potential interaction in the design, and after adjustment for multiple comparisons, the difference did not reach statistical significance. These results must undergo further investigation before they can be implemented in routine practice.

8) Hypertonic Saline- There are studies that support it as a therapy alone or in conjunction with steroids to reduce the length of stay once hospitalized but there are mixed results as to whether it is useful to help reduce admissions from the ED.

9) Nasal CPAP- Thia et al recruited children younger than 1 year with bronchiolitis and a capillary PCO2 level greater than 6 kPa and randomly assigned them to either nCPAP or standard treatment (IVF and O2 via NC) groups and then crossed them over to the alternative treatment after 12 hoursStudy results suggest that nCPAP improves ventilation in children with bronchiolitis and hypercapnia when compared with standard treatment.

10) Heliox- Cambonie et al conducted a prospective, randomized, double-blind study to determine the effects of heliox on respiratory distress symptoms in young infants (< 3 months of age) admitted to the pediatric intensive care unit (PICU) with moderate to severe acute RSV bronchiolitis. All infants were randomly and blindly assigned to inhale either heliox or an air-oxygen mixture for 1 hour under an oxyhood. The authors concluded that heliox breathing induced a rapid reduction in accessory muscle use and expiratory wheezing even in premature patients.

11) Ribavarin does not benefit

References

Subcommittee on Diagnosis and Management of Bronchiolitis. Diagnosis and Managagment of Bronchiolitis. PEDIATRICS Vol. 118 No. 4 October 2006, pp. 1774-1793

Fernandes Rm, et al. Glucocorticoids for acute viral bronchiolitis in infants and young children. Cochrane Database of Systematic Reviews 2010

Zhang L, et al. Nebulized hypertonic saline solution for acute bronchiolitis in infants. Cochrane Database of Systematic Reviews 2008.

Goh A, Chay OM, Foo AL, et al. Efficacy of bronchodilators in the treatment of bronchiolitis. Singapore Med J. 1997;38:326–328

Wang EE, Milner R, Allen U, et al. Bronchodialtors for treatment of mild bronchiolitis: a factorial randomized trial. Arch Dis Child. 1992;67:289–293