Editor’s note: This post represents a first in a series led by Drs. Ashley Lubberdink and Kaif Pardhan translating the pediatric guidelines that have been developed by TREKK (TRanslating Emergency Knowledge for Kids). For more information and further pediatric emergency medicine guidelines, please visit the TREKK website.
It is a cold January morning. A 5- month old male is brought to your community ED with a 4-day history of cough and nasal congestion. His mom was concerned as he appeared to be having difficulty breathing last night and this morning. He’s been tolerating oral intake well and has had no vomiting or diarrhea. He’s been voiding normally, every 4-6 hours. He was born at full term (39+5) via a vaginal delivery with no complications, and has had no medical problems up until now. He has received his 2 and 4 month immunizations. He appears well and responds appropriately to your physical exam and to his mother. His cap refill is less than 2 seconds and he has wet mucous membranes. His vital signs are T-36.8 rectally, HR 120, BP 90/50, RR 60, SpO2 87% RA. There is a diffuse expiratory wheeze bilaterally on auscultation, with abdominal breathing and some mild intercostal indrawing. The rest of the physical exam is unremarkable.
What is on your differential for wheezing in young children (<2 years)?
|Large airways||Smaller airways||Cardiac||GI||Other|
|Tracheoesophageal fistula||Viral bronchiolitis||CHF||GERD||Vascular ring|
|Laryngotracheomalacia*||Asthma||Congenital heart disease||Mediastinal mass|
|Foreign body aspiration*||Pneumonia: bacterial, viral, aspiration||Allergic reaction|
|Croup*||Chronic pulmonary disease|
*these may present with stridor over wheeze
What is Bronchiolitis?
Bronchiolitis is a common illness caused by viral infection in the terminal bronchiolar epithelial cells, leading to acute inflammation of these airways. Edema, necrosis of sloughed epithelial cells, and increased mucous production lead to obstruction and bronchospasm of these small airways.2
Bronchiolitis is typically caused by viruses. Although the actual proportion of disease based on each virus depends on the season of the year, respiratory syncytial virus (RSV) is the most common cause seen worldwide, followed by rhinovirus (the common cold virus). Less common causes include: parainfluenza virus type 3 which is more common in early spring/ late fall months, human metapneumovirus, influenza virus, adenovirus, coronavirus and human bocavirus. Co-infection with multiple viruses occur in 10-30% of young hospitalized children.1
It typically present as upper respiratory tract symptoms (nasal congestion/ discharge, cough), followed by symptoms of lower respiratory tract infection at days 2-3, peaking around day 5, with gradual resolution. Symptoms such as a cough may persist for up to 3 weeks in about 20% of children.2
Who is at risk for severe bronchiolitis, and what are the complications?
Most children with bronchiolitis do well and symptoms resolve within a few weeks. Groups that you should be more wary about include: children < 6 weeks of age, children with underlying cardio-respiratory disease, immunodeficiency, or significant prematurity, as they are at increased risk for developing complications of severe bronchiolitis.
The complications of severe bronchiolitis include dehydration, apnea, respiratory failure, and secondary bacterial infection (with the exception of acute otitis media, this is extremely rare). 2
Bronchiolitis is a CLINICAL DIAGNOSIS, meaning it should be diagnosed on the basis of a patient’s history and physical exam. If you are confident in your diagnosis, i.e., first episode of wheeze in a child < 24 months, typically (but not always) in the winter months, you can call it bronchiolitis!
“Do I need investigations?” you may ask yourself. If you are confident in your diagnosis, none are needed! Chest radiographs are not necessary to make the diagnosis of bronchiolitis, and should not be routinely performed, as they are associated with increased use of antibiotics. They should be considered only if the severity or course of illness suggests an alternative diagnosis. Lab investigations (i.e., CBC, blood cultures) are not indicated. Viral studies (NP swab) are not recommended unless doing so would alter management (i.e., initiation or discontinuation of antibiotics). A blood gas should be performed only if the clinician is concerned about potential respiratory failure. 1
What are the cornerstones for bronchiolitis treatment? Supportive care! This means ensuring adequate hydration and oxygenation. A limited amount of suctioning to clear the nares might be beneficial. Supplemental oxygen may be necessary if oxygen saturations are < 90% persistently. Antipyretics (acetaminophen or ibuprofen) for infants with high fever are often useful adjuncts for treatment and can reduce irritability.
What therapies are recommended based on evidence?1
- Oxygen: Supplemental O2 should be administered if saturations fall below 90%, and should be used to maintain saturations at >= 90%.
- Hydration: Frequent feeds and breastfeeding should be encouraged. NG and IV fluids appear equally effective.
What therapies have equivocal evidence?1
- Nebulized epinephrine: There is limited evidence for an observed trial of nebulized epinephrine for bronchiolitis. This may be something that is trialled for an infant that you are on the fence about sending home, however if the child does improve, they should be observed for some time prior to discharge. A typical dosage is 3 cc of 1:1000 Epi (most ED’s have this) or if your site has racemic epi, then the dose is 0.5 cc of 2.25% racemic epinephrine in 3 cc of normal saline.
- Nebulized 3% Hypertonic saline : This is a hotly debated topic, and more evidence will be needed before definitive recommendations go either way for this treatment. A Cochrane review of 11 trials suggested that nebulized hypertonic saline might be associated with a reduced length of hospital stay of 1 day when admission is >=3 days, however further larger, multicentre studies have shown mixed results3. Evidence of benefit in the outpatient setting is lacking.
- Combination of nebulized epinephrine and oral dexamethasone: More research is needed to assess the role of combination therapies.
What therapies are NOT recommended based on evidence?1
- Salbutamol: In children with bronchiolitis, the airways are obstructed in contrast to asthma in which they are constricted. Beta-agonists such as salbutamol have not been shown to improve a child’s O2 sat, reduce admission rates, or change duration of hospital stay. In those infants when your diagnosis is clear cut, a trial with salbutamol is not recommended.
- Corticosteroids: There is no evidence that oral or IV corticosteroids given alone can reduce hospital admissions or improve symptoms. For this reason, corticosteroids are not recommended.
- Antibiotics: As SBI are exceedingly rare, antibiotics are not recommended except in cases in which there is documented evidence of a SBI.
Asthma vs. Bronchiolitis
The CPS recently released a position statement clarifying the diagnosis and management of asthmas in preschoolers, and touches upon the differentiation of asthma from bronchiolitis. It is often difficult for clinicians to separate the two in young toddlers due to similar clinical presentations of airflow obstruction and viral URTI. The CPS suggests that bronchiolitis is more likely in the first episode of cough, wheezing, and respiratory distress episode in an infant < 12 months of age, whereas asthma typically starts in toddlers 1-3 years of age. If an infant < 1 year of age has repeated (≥2) episodes of wheeze, this should raise the suspicion of asthma. In children who are ≥ 1 year of age, a trial of response to asthma medications may be appropriate.5
Most infants and children with bronchiolitis do just fine and can be sent home.
Infants who require either IV or NG fluids to maintain hydration, infants who require supplemental oxygen to keep saturations > 90%, and infants who have persistent respiratory distress, should be considered for inpatient hospital admission. 2
You might also consider closely observing or admitting infants < 6 weeks of age, premature infants (<35 weeks GA), infants with underlying cardio-respiratory disease or immunodeficiency, infants who present to ED with high heart rates and respiratory rates (HR > 180, RR > 80), even if they appear to have improved in the ED.2
Hospital admission enables regular clinical assessments, where vital signs, work of breathing, detection of apnea episodes, providing supplemental O2, and managing hydration status can be provided.
Back to the case:
Bronchiolitis was the diagnosis made on a clinical basis for this patient, as the history and physical examination findings suggested this first episode of wheezing in this 5 month old infant was due to a viral etiology.
Our patient did not have a history of prematurity (<35 weeks) and was not < 6 weeks of age. He also did not have underlying cardio-respiratory disease, immunodeficiency, signs of dehydration, or worrisome HR/ RR on ED presentation. However, our patient did require supplemental oxygen to keep his saturations >=90%, and for that reason, the Pediatrics team was consulted, and the patient was admitted to hospital for observation and oxygen supplementation. The patients mother was advised to continue breastfeeds regularly to avoid dehydration. No laboratory investigations or radiography was performed, and no treatment other than supplemental oxygen was administered.
Reviewing with the Staff
This summary captures the most important take home message when it comes to managing bronchiolitis – “do less”.
Multiple studies have captured the extensive and widespread use of medications and investigations that have no benefit in managing or diagnosing. Bronchiolitis, as outlined in this summary, is a clinical diagnosis. The typical patient with bronchiolitis is an infant less than a year of age who presents with their first episode of wheezing in the months during RSV “season”. Chest x-rays and viral studies have little role in the diagnosis of bronchiolitis.
Clinical practice guidelines published across the globe overwhelmingly indicate that supportive care in the form of fluids and oxygen is the mainstay of management in bronchiolitis and not, as have been used extensively in the past, bronchodilators!