Bronchiolitis Flashcards
Define Bronchiolitis
Viral LRTI characterized by small airways obstruction caused by acute inflammation, edema and necrosis of the epithelial cells lining small airways and increased mucus production
What is the most common cause of bronchiolitis?
RSV
List other viruses that commonly cause bronchiolitis
- HMPV
- Influenza
- Rhinovirus
- Adenovirus
- Parainfluenza virus
What is the rate of co-infection with bronchiolitis?
10-30%
When does bronchiolitis season start in Canada?
Between November and January
How long does bronchiolitis season last?
4-5 months
What is the incidence of bronchiolitis?
1/3 children affected in the first 24 months of life
What is the most common cause for admission to hospital in the first year?
Bronchiolitis
What is the rate of hospitalization for bronchiolitis?
Hospitalization rate has increased from 1-3% in the past 30 years
What is the goal of the CPS statement for bronchiolitis?
Decrease in unnecessary diagnostic studies and ineffective medications and interventions
Who is excluded from this statement?
- Chronic lung disease
- Immunodeficiency
- Serious underlying chronic disease
What is the typical first presentation of bronchiolitis?
First episode of wheezing before the age of 12 months
What is the history of bronchiolitis?
- 2-3 day viral prodrome of fever, cough and rhinorrhea
- Progresses to tachypnea, wheeze, crackles and respiratory distress
- Exposure to an individual with viral URI
LIst 5 signs of respiratory distress
- Grunting
- Nasal flaring
- Indrawing
- Retractions
- Abdominal breathing
What are signs of respiratory illness?
- Intercostal/subcostal retractions
- Accessory muscle use
- Nasal flaring
- Grunting
- Colour change/apnea
- Wheezing/crackles
- Hypoxia
- Tachypnea
List a differential diagnosis for wheezing
- Laryngotracheomalacia
- FBA
- Pneumonia
- Viral bronchiolitis
- CF
- Asthma
- Allergic reaction
- TEF
- Mediastinal mass
- Vascular ring
- CHF
- GERD
List physical examination findings in bronchiolitis
- Respiratory distress
- Crackles/wheezing
- Tachypnea
- Hypoxia
- Dehydration
What is the typical CXR in bronchiolitis?
- CXR shows patchy nonspecific areas of hyperinflation and atelectasis
- May be interpreted as consolidation
When to order a CXR in bronchiolitis?
- Diagnosis of bronchiolitis unclear
- Rate of improvement not as expected
- Disease severity raises other diagostic possibilities (pneumonia)
What is the value of nasopharyngeal swabs in bronchiolitis?
- Not helpful from a diagnostic perspective
- Don’t change management
- ?useful for cohorting as the rate of infection is up to 30%
What is the value of CBC in bronchiolitis?
Not been found to be useful in predicting serious bacterial infections
Which patients have the greatest risk of SBI?
Infants in the first two months of life, especially UTI
What is the rate of SBI in infants with bronchiolitis?
0-6.1%
What is the incidence of bacteremia in bronchiolitis?
<1%
What is the indicence of meningitis complicating bronchiolitis?
Extremely rare
When to order a blood gas in bronchiolitis?
When concerned about impending respiratory failure
Which groups are at higher risk for severe disease?
- Infants born prematurely (< 35 weeks)
- < 3 months at presentation
- Hemodynamically significant cardiopulmonary disease
- Immunodeficiency
What are criteria for admission in bronchiolitis?
- Signs of severe respiratory distress (grunting, indrawing, RR > 70)
- Supplemental O2 required to keep sats > 90%
- Dehydration or history of poor fluid intake
- Cyanosis or history of apnea
- Infant at high risk for severe disease
- Family unable to cope
What is the natural history of bronchiolitis?
Disease worsens over the first 72 hours
List predictors of hospitalization in bronchiolitis
- Accessory muscle score of >6/9
- O2 saturation < 92%
- RR > 60
- Poor hydration
What is the role of pulse oximetry in clinical decision making?
- Setting arbitrary thresholds for oxygen therapy will influence admission rates
- Significant increase in recommending admission by reducing saturation from 94% to 92% in clinical vignettes
What are the mainstays of treatment in bronchiolitis?
- Supportive care
- Gentle nasal suctioning
- Minimal handling
- Assisted feeding
- Oxygen therapy
Which therapies are recommended in bronchiolitis?
- Oxygen
- Hydration
For which therapies in bronchiolitis is the evidence equivocal?
- Epinephrine nebulization
- Nasal suctioning
- 3% hypertonic saline
- Combined epinephrine and dexamethasone
Which therapies are not recommended for bronchiolitis?
- Salbutamol
- Antibiotics
- Antiviral
- Cool mist therapies or nebulized saline
- Corticosteroids
- Chest physiotherapy
When to administer supplemental oxygen?
If saturations fall below 90% and used to maintain saturations above 90%
What percentage of hospitalized patients will need fluid supplementation?
30%
When is PO feeding contraindicated?
With RR > 60
What route of fluid administration is most effective?
NG and IV routes equally effective with no difference in LOS
What type of IV fluids should be used in bronchiolitis?
Isotonis fluids like D5NS with regular monitoring of serum sodium because of the risk of hyponatremia
What is the role of nebulized epinephrine in bronchiolitis?
- Epinephrine and steroids together reduce hospital admissions
- Evidence insufficient to recommend routine use of nebulized epinephrine in the ED
- Resonable to administer a dose and monitor for a clinical response
- Epinephrine doesn’t reduce LOS, therefore insufficient evidence to support its use for inpatients
What types of suctioning are associated with increased LOS?
Deep and infrequent suctioning
What is the hypothesized mechanism of action for hypertonic saline?
- Increases mucociliary clearance and rehydrates airway surface liquid
What are the results of the cochraine review evaluating the use of hypertonic saline in bronchiolitis?
Cochrane review of 11 trials found reduced LOS by one day where the admission was longer than three days
What is the optimal dosing regimen for hypertonic saline?
Remains unclear
Q8H most commonly used
What is the best evidence for use of hypertonic saline?
For admitted patients rather than outpatient
For patients with an anticipated longer LOS
What is the role for combination epi and dex in bronchiolitis?
- Reduced hospitalization rate
- NNT = 11
- Results rendered nonsignificant when adjusted for multiple comparisons
- Not currently recommended for the therapy of otherwise well kids with bronchiolitis
Why is ventolin not recommended for bronchiolitis?
- Pathophysiology of asthma is constricted airways vs. obstructed airways seen in bronchiolitis
- Infants have inadequate B receptor agonist lung receptor sites and immature bronchiolar smooth muscles
- Ventolin does not reduce admission rates
- Ventolin does not shorten LOS
- Ventolin does not improve saturation
What is the role of corticosteroids in bronchiolitis?
- Not associated with clinically significant improvement in disease measured by reduced clinical scores, rates of hospitalization and LOS
- Any benefit must be weighed against the risksk of steroid administration
When is it appropirate to use antibiotics in the management of bronchiolitis?
- When there is clear documented evidence of a secondary bacterial infection
What is the role of antiviral therapy in bronchiolitis?
- Antivirals are expensive, cumberson to administer, provide limited benefit and are potentially toxic to care providers
- Antivirals can be considered in patients at risk for particularly severe disease
- Decision should be made on an individual basis in consultation with appropriate subspecialists
What is the role of chest physiotherapy in bronchiolitis?
- Neither vibration or percussion techniques shown to improve clinical scores, reduce hospital stay or duration of symptoms
- Not recommended for the treatment of bronchiolitis
What is the role of cool mist therapies and aerosol therapies in bronchiolitis?
Recent cochrane review concluded there is no evidence suporting or refuting the use of cool mist and aerosols for managing bronchiolitis
How reduce the nosocomial transmission of bronchiolitis?
- Contact isolation
- Conflicting evidence regarding the benefits of cohorting patients
What is the most important component of monitoring infants admitted with bronchiolitis?
Regular and repeated clinical assessments
What are the drawbacks of continuous monitoring in bronchiolitis?
- May prolong LOS especially if staff respond to normal transient dips in oxygen saturation or changes in heart and respiratory rates with interventions
- Accuracy of pulse oximetry is relatively poor, especially at saturations < 90%
What is the primary rationale for cardiorespiratory monitoring in bronchiolitis?
To detect episodes of apnea requiring intervention
What is the rate of apnea in RSV bronchiolitis?
In a large study with 691 infants < 6 months old, 2.7% had a documented apnea and all had high risk criteria
Who is at higher risk for apneas with bronchiolitis?
- < 1 month old
- < 48 weeks postconception in prems
Who should have continuous cardiorespiratory monitoring?
- High risk patients in the acute phase of illness
- Continuous monitoring is good for identifying infants who are deteriorating and need escalation of therapy
- Many healthy infants exhibit typical transient O2 saturation dips
- LOS can be prolonged if O2 therapy is based on arbitrary targets
Who can be switched to intermittent O2 sat monitoring?
- Lower risk patients
- All patients once they are feeding well, weaning from suppemental O2 and have improved WOB
What are the criteria for discharge?
- Tachypnea and WOB improved
- Maintain O2 sats > 90% without supplemental O2 or stable for home O2 therapy
- Adequate PO feeding
- Education provided and adequate follow up arranged
