1. Bronchiolitis Caused by RSV: A Clinical Review
This presentation, RSV, Bronchiolitis and the Role of High Flow Therapy: A Clinical Review, is worth 1 CEU credit for Respiratory Therapists. It is presented as part of the Vapotherm Education Center. To receive credit for this course, the learned must complete the course, assessment and course evaluation.
VAPOTHERM
The Standard in High Flow Therapy

2. RSV and Bronchiolitis Etiology, Epidemiology and Pathophysiology
In this section, we provide and overview of RSV and bronchiolitis.

3. Course Objectives Define bronchiolitis and RSV
Understand the etiology, pathophysiology and epidemiology of bronchiolitis caused by RSV
Explain the clinical signs and symptoms of bronchiolitis
Understand how the characteristics of High Flow Therapy (HFT) play a role in the treatment of the symptoms of Bronchiolitis
Review key research on the application of High Flow Therapy in pediatric bronchiolitis patients
The course objectives are as follows. Upon completion of the course, the learner should be able to:
Define bronchiolitis and RSV
Understand the etiology, pathophysiology and epidemiology of bronchiolitis caused by RSV
Explain the clinical signs and symptoms of bronchiolitis
Understand how the characteristics of High Flow Therapy (HFT) play a role in the treatment of the symptoms of Bronchiolitis
Review key research on the application of High Flow Therapy in pediatric bronchioilitis patients

4. Bronchiolitis Acute inflammation of the bronchioles
characterized by swelling and mucus buildup
Typically caused by a viral infection such as RSV
Prevalent in young infants
The leading cause of infant hospitalization in the US
Bronchiolitis is a condition characterized by swelling of the bronchioles and mucus buildup that is usually caused by a viral infection. Although it may occur in persons of any age, severe symptoms are evident in young infants; the larger airways of older children and adults better accommodate mucosal edema.
Chest x-ray of infant with RSV (James Heilman, MD)

5. Overview of Bronchiolitis Caused By RSV
In children under 1 year, RSV is the most common cause of bronchiolitis
All children get RSV in first 3 years of life but in a small % of them, it creates serious infection
Most common cause of lower respiratory tract infection in the first year of life
Bronchiolitis typically affects children younger than 2 years, with a peak in infants aged 3-6 months. Acute bronchiolitis is the most common cause of lower respiratory tract infections in the first year of life. It is generally a self-limiting condition and is most commonly associated with respiratory syncytial virus (RSV) (sin-SISH-uhl)

6. Bronchiolitis: Etiology
Most cases result from a viral pathogen
RSV
Parainfluenza virus
Influenza virus
Adenovirus
RSV is the most common
75% of children younger than 2 hospitalized for bronchiolitis.
Bronchiolitis in the ED1
277 samples tested
Positive for:
RSV – 64%
Rhinovirus - 16%
Human metapneumovirus (hMPV) - 9%
Influenza A virus - 6%
Most cases of bronchiolitis result from a viral pathogen, such as RSV, parainfluenza virus, influenza virus, or adenovirus.
RSV is the most commonly isolated agent in 75% of children younger than 2 years who are hospitalized for bronchiolitis.
In a prospective multicenter study of the viral etiology of bronchiolitis in the emergency department (ED), 277 samples were tested, and positive samples were obtained for the following viruses[1] : RSV - 64%, Rhinovirus - 16%, Human metapneumovirus (hMPV) - 9%, Influenza A virus - 6%
1. Mansbach JM, McAdam AJ, Clark S, Hain PD, Flood RG, Acholonu U. Prospective multicenter study of the viral etiology of bronchiolitis in the emergency department. Acad Emerg Med. Feb 2008;15(2):111-8.

7. Respiratory Syncytial Virus: RSV
RSV is an enveloped RNA virus
Two strains (A & B ) are recognized
RSV is from common viral family (Paramyxovirdae)
RSV infection can be confirmed using a simple lab technique
Direct Fluorescent Antibody detection (DFA),
Transmission Electron Micrograph of RSV
RSV is an enveloped RNA virus and two strains (A & B ) are recognized
RSV is a negative-sense, single-stranded RNA virus of the family Paramvxovirdae
RSV infection can be confirmed using  Direct Fluorescent Antibody detection (DFA),

8. Transmission Highly contagious Spreads through: nasal secretions
airborne droplets
Fomites
Highly contagious and the virus that causes it is spreads from person to person through direct contact with:
nasal secretions
airborne droplets
Fomites

9. RSV: Epidemiology
Each year, nearly 125,000 children are hospitalized due to an RSV infection
RSV is seasonal
93% of cases occurring between November and April
Reinfection is common
Virtually all children experience RSV infection within the first 3 years of life, but previous infection does not convey complete immunity. Reinfection is common; however, significant antibody titers from previous infection ameliorate the severity of symptoms
In children under 1 year, RSV is the most common cause of bronchiolitis
All children get RSV first 3 years of life but in a small % of them, it creates serious infection
Each year, nearly 125,000 children are hospitalized due to an RSV infection
RSV is seasonal, with most cases occuring between November and April
Reinfection is common. The chart on the right is repoduced from the Centers for Disease Control and shows the duration of the RSV season by regions.
Attack rates within families are as high as 45% and are higher in childcare centers. Rates of hospital-acquired infection range from 20-47%.
From CDC

10. Bronchiolitis: Epidemiology
More than 1/3 of children develop bronchiolitis in the first two years of life
3% of infants hospitalized in U.S.
Low mortality with fewer than 400 deaths annually
For infants under 6 months, 17 hospitalizations and 55 ED visits per 1000 children due to RSV
More than 1/3 of children develop bronchiolitis in the first two years of life
Of these, approximately 1 in 10 are hospitized representing ~3% of the infants in the US
High morbidity and hospitalization rate, but low mortality with fewer than 400 deaths annually
A recent study showed yearly rate for RSV alone for infants under 6 months was 17 hospitalizations and 55 ED visits per 1000 children

11. Bronchiolitis: Pathophysiology
The effects of bronchiolar injury include the following:
Increased mucus secretion
Bronchial obstruction and constriction
Alveolar cell death, mucus debris, viral invasion
Air trapping
Atelectasis
Labored breathing
The effects of bronchiolar injury include the following: Increased mucus secretion, Bronchial obstruction and constriction, Alveolar cell death, mucus debris, viral invasion, Air trapping, Atelectasis, Reduced ventilation that leads to ventilation-perfusion mismatch, Labored breathing

12. Pathophysiology in Infants
Infants are affected because:
Small airways
High closing volumes
Insufficient collateral ventilation
Recovery:
Regeneration of bronchiolar epithelium after 3-4 days
Cilia do not appear for as long as 2 weeks.
Infants are affected most often because of their small airways, high closing volumes, and insufficient collateral ventilation.
Recovery begins with regeneration of bronchiolar epithelium after 3-4 days; however, cilia do not appear for as long as 2 weeks.

13. Risk Factors
Risk factors for the development of bronchiolitis include the following:
Low birth weight
Gestational age
Lower socioeconomic group
Crowded living conditions / daycare
Parental smoking
Risk factors for the development of bronchiolitis include the following:
Low birth weight, particularly premature infants³
Gestational age (independently associated with hospital resource use and outcome among infants hospitalized for RSV infection)
Lower socioeconomic group⁴
Crowded living conditions, daycare, or both
Parental smoking
3. Horn SD, Smout RJ. Effect of prematurity on respiratory syncytial virus hospital resource use and outcomes. J Pediatr. Nov 2003;143(5 Suppl):S
4. Glezen WP, Paredes A, Allison JE, et al. Risk of respiratory syncytial virus infection for infants from low- income families in relationship to age, sex, ethnic group, and maternal antibody level. J Pediatr. May 1981;98(5):
5. Carroll KN, Gebretsadik T, Griffin MR, et al. Maternal asthma and maternal smoking are associated with increased risk of bronchiolitis during infancy. Pediatrics. Jun 2007;119(6):

14. Risk Factors
Chronic lung disease, particularly bronchopulmonary dysplasia
Severe congenital or acquired neurologic disease
CHD w/ pulmonary hypertension
Congenital or acquired immune deficiency diseases
Age less than 3 months
Airway anomalies
Chronic lung disease, particularly bronchopulmonary dysplasia
Severe congenital or acquired neurologic disease
Congenital heart disease (CHD) with pulmonary hypertension[38] ; however, a study of Swiss children with CHD did not show increased risk⁶
Congenital or acquired immune deficiency diseases
Age less than 3 months
Airway anomalies
6. Duppenthaler A, Ammann RA, Gorgievski-Hrisoho M, Pfammatter JP, Aebi C. Low incidence of respiratory syncytial virus hospitalisations in haemodynamically significant congenital heart disease. Arch Dis Child. Oct 2004;89(10):961-5.

15. Diagnosis and Treatment
Symptoms, Admissions Criteria and Treatment

16. Clinical Signs & Symptoms
Examination often reveals the following:
Tachypnea
Tachycardia
Fever (38-39°C)
Retractions / nasal flaring
Fine rales / Diffuse, fine wheezing
The diagnosis is made on the basis of age and seasonal occurrence, tachypnea, and the presence of profuse coryza (snotty nose) and fine rales, wheezes, or both upon auscultation of the lungs.
Hypoxia is the best predictor of severe illness and correlates best with the degree of tachypnea (>50 breaths/min). The degree of wheezing or retractions correlates poorly with hypoxia. First-time infections are usually most severe; subsequent attacks are generally milder, particularly in older children.
In most cases the diagnosis of bronchiolitis is clinically evident and does not require the use of radiographs or lab tests.

17. Hospital Admissions Criteria
Respiratory Status
Respiratory distress, apnea, Tachypnea (>70 br/min) and/or clinical evidence of increased work of breathing
Patient requires oxygen supplementation
Patient requires continuous clinical assessment of airway clearance and maintenance using bulb suctioning
Nutritional Status
Patient is dehydrated
Patient is unable to maintain oral feedings at a level to prevent dehydration
AHRQ national guidelines
Admissions criteria often include the following. These criteria are from Agency for Healthcare Research and Quality (AHRQ) national guidelines from the Cincinatti Childrens Hospital
Respiratory Status
Respiratory distress, apnea, respirations greater than 70 per minute and/or clinical evidence of increased work of breathing
Patient requires oxygen supplementation
Patient requires continuous clinical assessment of airway clearance and maintenance using bulb suctioning
Nutritional Status
Patient is dehydrated
Patient is unable to maintain oral feedings at a level to prevent dehydration
Social
Parent or guardian is not prepared to provide care at home
Family education is not complete
Home resources are inadequate to support the use of any necessary home therapies

18. Complications Acute respiratory distress syndrome (ARDS)
Bronchiolitis obliterans
Congestive heart failure
Secondary infection
Myocarditis
Arrhythmias
Chronic lung disease
With bronchiolitis, as with any disease, various complications are possible, including those caused by therapy. In most cases, the disease is mild and self-limiting. However, in infants who are immunosuppressed and those with preexisting heart or lung disease, RSV bronchiolitis can result in any of the following: Acute respiratory distress syndrome, bronchiolitis obliterans, congestive heart failure, secondary infection, myocarditis, arrhythmias, and chronic lung disease.

19. Treatment and Management
No definitive treatment
At present, only oxygen appreciably improves the condition of young children with bronchiolitis.7
Medications have a limited role in the management of RSV and bronchiolitis
Because no definitive treatment for the specific virus exists, therapy is directed toward symptomatic relief and maintenance of hydration and oxygenation.
Medical therapies used to treat bronchiolitis in infants and young children are controversial. Although numerous medications and interventions have been used to treat bronchiolitis, at present, only oxygen appreciably improves the condition of young children with bronchiolitis.
7. Unger S, Cunningham S. Effect of oxygen supplementation on length of stay for infants hospitalized with acute viral bronchiolitis. Pediatrics. Mar 2008;121(3):470-5.
The American Academy of Pediatrics published guidelines Diagnosis and Management of Bronchiolitis in 2006.
Medications have a limited role in the management of bronchiolitis. Several drugs are commonly used (eg, bronchodilators), but there is little in the way of conclusive evidence to support routine use of any drug in the management of RSV and bronchiolitis.
Bronchodilators – produce only modest, short-term improvement.
Research also does not support the rooutine use of Antivirals and Antibiotics –

20. Treatment & Management in Hospitalized Patients
Mild Cases:
Cardio-respiratory Monitoring
Pulse Oximetry
Oxygenation Supplementation
Maintenance of Hydration
Moderate & Severe Cases:
CPAP
Humidification
High flow nasal cannula
Mechanical ventilation
Treatment for bronchiolitis from RSV is generally supportive. Antibiotics do not treat RSV. In mild cases, the infection will go away without treatment. In more severe cases, increased air flow and oxygen therapy may be utilized. In the most severe cases, ventilation may be necessary.

21. Traditional Respiratory Support
Low Flow Oxygen
Non-Invasive Ventilation
There were historically three modalities used to treat RSV bronchiolitic patients depending on the severity of the illness. Each of these methods has advantages and disadvantages depending on the situation. In extreme cases, intubation and mechanical ventilation may be necessary. While sometimes necessary, the impact of mechanical ventilation is well known and can result in increased length of stay, patient discomfort and increased risk of secondary infections.
Low flow oxygen cannula or mask therapy can manage some patients, but are not enough support for others; oxygen therapies provide for oxygenation, but not ventilation. Patient adherence can also be an issue, particularly where masks are concerned. Non-invasive ventilation can provide more support than low flow oxygen, but has its own limitations, particularly with aspects related to the mask and patient compliance.
Intubation

22. High Flow Therapy
Respiratory Support for Bronchiolitis

23. Accepted standard of care:
Humidity
Humidified oxygen therapy is an accepted standard of care, and high flow therapy via nasal cannula offers both and the added benefits of higher flows and a simple, comfortable patient interface. This modality brings a higher level of respiratory support to the patient, without the side effects of more invasive or intrusive methods.

24. Effects of High Flow Therapy via Nasal Cannula on Bronchiolitis:
Setting flow rates to exceed the patients inspiratory demand:
Flush out of dead space removes CO2
Creates internal reservoir of desired FiO2
Patient breathes through own airway instead of from external source (ie: mask)
Lets take a look at the effects of humidified high flow therapy on bronchiolitis. With high flow therapy via nasal cannula, it is possible to deliver higher flows than through a conventional nasal cannula, It is possible due to technological advances in humidification, which allow breathing gases to be delivered at optimal temperature and high humidity up to 40 liters per minute in adults and up to 20 liters in children. These high flows can be delivered comfortably for the patient and allow the clinician to set flow rates that meet or exceed the patient’s inspiratory demand. Instead of breathing from an external reservoir, the patient’s own nasapharynyx becomes the reservoir of fresh gas and desired Fi02. At the same time, these high flows provide a flushing of the anatomical deadspace, removing C02 and decreasing the work of breathing.
Decreases work of breathing

25. How High Flow Therapy Impacts Bronchiolitis:
Why is heat and humidity important?
Allows tolerability of higher flow rates
Improves mucocilliary process
Why is heat and humidity important in managing the symptoms associated with bronchiolitis and RSV?
Firsts, the fact that gas is conditioned to body temperature saturated with water vapor means higher flows are possible to meet or exceed the inspiratory demands of the patient. The humidification improves the mucociliary clearance and heating means there is decreased energy expenditure for the patient.
Decreases energy expenditure

26. Effects of HFT on Bronchiolitis:
Inflammed bronchiole as a result of bronchiolitis
Ideally heated and humidified gas improves and facilitates airway conductance
Once open, much needed oxygen can now reach the alveoli, allowing for proper gas exchange
In bronchiolitis, the bronchiole walls become inflamed and constricted, while at the same time filling with mucus. This combination causes an increase in work of breathing and subsequent poor gas exchange. The constriction of the bronchioles and mucus build up limits air flow to the lower alveoli.
As ideally heated and humidified gas reaches the inflamed areas, the bronchiole receptors in the smooth muscle wall relax, dilating the bronchioles. The humidification in the gas also affects the viscosity of the mucus, lowering its density and allowing for easier expulsion. This combination allows for greater gas flow to the alveoli, decreasing work of breathing and increasing oxygenation.

27. The Importance of Humidification:
Damaged cilia
Mucus collection
Due to dry, underconditioned gas, the cilia movement stops. Because the cilia has stopped, it does not propel the mucus forward to enhance airway clearance. The bronchiole, already restricted due to inflammation, is further restricted with the occlusion of mucus, thus causing an increased work of breathing and oxygen deprivation by obstructing air flow.

28. The Importance of Humidification:
Heated and humidified gas restores cilia to its natural state, allowing for secretion clearance
As ideally conditioned gases, heated to body temperature and completely saturated with water vapor reaches the airway, the ciliary process is restored. Mucus begins to be propelled forward and removed from the lower airway, allowing for lower airway resistance, decreased work of breathing and an increase in gas exchange.

29. Clinical Impact By instituting High Flow Therapy: Secretion Management
Provide precise FiO2
Reduce WOB with dead space flush
Allows for better feeding tolerance
By instituting High Flow Therapy:
Floors or ICU – Lower intensity of care
Provide precise FiO2 to maintain adequate O2 saturation
Reduce WOB with dead space flush by providing flow rates which exceed the patients inspiratory demand
As WOB is decreased, the chance of patient fatiguing, requiring more invasive modalities also decreases
Decrease WOB also allows for better feeding tolerance

30. Improving Patient Tolerance & Comfort
Not a mask therapy, resolves:
Tolerance and adherence issues
Feeding issues
High flow cannula provides:
simple interface
Improves comfort / tolerance
Less skin trauma
Decreased acuity of care
Mask therapies and NIV can provide needed respiratory support but lack the simplicity of the nasal cannula interface. The cannula provides comfort fot the patient and easy management for the clinician.
The Simplicity of the Nasal Cannula

31. Research Review High Flow Therapy and Bronchiolitis
In this next section, we briefly review recent research concerning the application of high flow therapy in pediatric bronchiolitis patients

32. A retrospective chart review to:
Reduced intubation rates for infants after introduction of high-flow nasal prong oxygen delivery Schibler A, Pham TM, Dunster KR, Foster K, Barlow A, Gibbons K, Hough JL. Intensive Care Med. 2011; 37(5):
A retrospective chart review to:
Describe the change in PICU ventilatory practice after adoption of HFT.
Identify the patient subgroups requiring escalation of therapy.
We will review two studies concerning high flow therapy in patients with bronchiolitis. Additional studies are referenced in the course resources.
In a study by Schhibler et al Between January 2005 and December 2009, a total of 298 infants <24 months of age received HFNP therapy. Overall, 36 infants (12%) required escalation to invasive ventilation. In the subgroup with a primary diagnosis of viral bronchiolitis (n = 167, 56%), only 6 (4%) required escalation to invasive ventilation. The rate of intubation in infants with viral bronchiolitis reduced from 37% to 7% over the observation period corresponding with an increase in the use of HFNP therapy. No adverse events were identified with the use of high flow nasal cannulatherapy

33. Schibler et al. Intensive Care Med. 2011;37(5):847-52.
Overall
298 infants <24 months of age received HFT.
36 infants (12%) required escalation to MV
No adverse events
Subgroup - viral bronchiolitis
Of 167 infants, only 6 (4%) required escalation to MV.
Rate of intubation reduced from 37% to 7%, corresponding to an increase in the use of HFT.
We will review two studies concerning high flow therapy in patients with bronchiolitis. Additional studies are referenced in the course resources.
In a study by Schhibler et al Between January 2005 and December 2009, a total of 298 infants <24 months of age received HFNP therapy. Overall, 36 infants (12%) required escalation to invasive ventilation. In the subgroup with a primary diagnosis of viral bronchiolitis (n = 167, 56%), only 6 (4%) required escalation to invasive ventilation. The rate of intubation in infants with viral bronchiolitis reduced from 37% to 7% over the observation period corresponding with an increase in the use of HFNP therapy. No adverse events were identified with the use of high flow nasal cannulatherapy

34. Schibler et al. Intensive Care Med. 2011;37(5):847-52.
Conclusions: HFNP therapy has dramatically changed ventilatory practice in infants <24 months of age Appears to reduce the need for intubation in infants with viral bronchiolitis.
We will review two studies concerning high flow therapy in patients with bronchiolitis. Additional studies are referenced in the course resources.
In a study by Schhibler et al Between January 2005 and December 2009, a total of 298 infants <24 months of age received HFNP therapy. Overall, 36 infants (12%) required escalation to invasive ventilation. In the subgroup with a primary diagnosis of viral bronchiolitis (n = 167, 56%), only 6 (4%) required escalation to invasive ventilation. The rate of intubation in infants with viral bronchiolitis reduced from 37% to 7% over the observation period corresponding with an increase in the use of HFNP therapy. No adverse events were identified with the use of high flow nasal cannulatherapy

35. High Flow Nasal Cannulae Therapy in Infants with Bronchiolitis McKiernan C, Chua LC, Visintainer PF, Allen H Journal of Pediatrics. 2010; 156(4):
A retrospective chart review to of infants <24 months old with bronchiolitis Goal to determine if the introduction HFT was associated with decreased rates of intubation
In a study by Mckiernan et al the authors found in the season after the introduction of HFNC, only 9% of infants admitted to the PICU with bronchiolitis required intubation, compared with 23% in the prior season (P=.043). This 68% decrease in need for intubation persisted in a logistic regression model controlling for age, weight, and RSV status. HFNC therapy resulted in a greater decrease in respiratory rate compared with other forms of respiratory support, and those infants with the greatest decrease in respiratory rate were least likely to be intubated. In addition, median PICU length of stay for children with bronchiolitis decreased from 6 to 4 days after the introduction of HFNC.
The authors hypothesize that HFNC decreases rates of intubation in infants with bronchiolitis by decreasing the respiratory rate and work of breathing by providing a comfortable and well-tolerated means of noninvasive ventilatory support
The authors hypothesize

36. McKiernan et al. Journal of Pediatrics. 2010; 156(4): 634-638.
Season after the introduction of HFT vs Season prior:
Decrease in intubation from 23% to 9% (p < 0.05)
HFNC therapy resulted in a greater decrease in respiratory rate compared with other forms of respiratory support
infants with the greatest decrease in respiratory rate were least likely to be intubated
Median PICU length of stay decreased from 6 to 4 days
In a study by Mckiernan et al the authors found in the season after the introduction of HFNC, only 9% of infants admitted to the PICU with bronchiolitis required intubation, compared with 23% in the prior season (P=.043). This 68% decrease in need for intubation persisted in a logistic regression model controlling for age, weight, and RSV status. HFNC therapy resulted in a greater decrease in respiratory rate compared with other forms of respiratory support, and those infants with the greatest decrease in respiratory rate were least likely to be intubated. In addition, median PICU length of stay for children with bronchiolitis decreased from 6 to 4 days after the introduction of HFNC.
The authors hypothesize that HFNC decreases rates of intubation in infants with bronchiolitis by decreasing the respiratory rate and work of breathing by providing a comfortable and well-tolerated means of noninvasive ventilatory support
The authors hypothesize

37. McKiernan et al. Journal of Pediatrics. 2010; 156(4): 634-638.
HFT appears to decreases rates of intubation in infants with bronchiolitis by decreasing the respiratory rate and work of breathing Provides a comfortable and well-tolerated means of noninvasive ventilatory support.
In a study by Mckiernan et al the authors found in the season after the introduction of HFNC, only 9% of infants admitted to the PICU with bronchiolitis required intubation, compared with 23% in the prior season (P=.043). This 68% decrease in need for intubation persisted in a logistic regression model controlling for age, weight, and RSV status. HFNC therapy resulted in a greater decrease in respiratory rate compared with other forms of respiratory support, and those infants with the greatest decrease in respiratory rate were least likely to be intubated. In addition, median PICU length of stay for children with bronchiolitis decreased from 6 to 4 days after the introduction of HFNC.
The authors hypothesize that HFNC decreases rates of intubation in infants with bronchiolitis by decreasing the respiratory rate and work of breathing by providing a comfortable and well-tolerated means of noninvasive ventilatory support
The authors hypothesize

38. Summary of Study Conclusions
High flow therapy has been shown to reduce intubation rates in infants with bronchiolitis
High flow therapy is well tolerated
High flow therapy administered with heliox further improved respiratory scores
In summary, studies show:
High flow therapy may reduce intubation rates in infants with bronchiolitis
High flow therapy is well tolerated
High flow therapy delivered with heliox improved respiratory scores

39. Thank You ! Questions?

40. Resources: Clinical Practice Guidelines
American Academy of Pediatrics, Diagnosis and Management of Bronchiolitis, 2006
Cincinnati Children's Hospital Medical Center (CCHMC). Evidence-based care guideline for management of first time episode bronchiolitis in infants less than 1 year of age. Cincinnati, OH
Scottish Intercollegiate Guidelines Network (SIGN). Bronchiolitis in children. A national clinical guideline. Edinburgh (Scotland): Scottish Intercollegiate Guidelines Network (SIGN); 2006 Nov. 41 p
Clinical practice guidelines are available for the diagnosis, treatment and prevention of bronchiolitis and are available on the National Guidelines Clearinghouse at guideline.gov and through publications of the American Academy of Pediatrics.