Transcript Bronchiolitis: Management Strategies and Controversies

Bronchiolitis: Management
Strategies and Controversies
Moyez B. Ladhani
Disclosures: None
Objectives:
• Review RSV
• Review Pathophysiology,
• Presentation
• Management
Introduction:
• Viral bronchiolitis is the commonest lower
respiratory tract infection in children less
than 12 months of age and is the most
frequent cause of hospitalization in infants
under 6 months of age.
• It is caused by viral infections of the lower
respiratory tract, principally by respiratory
syncytial virus (RSV).
Introduction:
• Outbreaks occur worldwide during the
late fall, winter, and early spring.
• In North America, the season generally
begins in early November and
continues through April.
RSV Season in the US
Introduction:
• Fifty percent of all children develop
RSV infection by 12 months of age; by
2 years of age, virtually all children
have had RSV infection.
Introduction:
• Reinfections with RSV occur throughout
life. Reinfection rates among preschool
children can range from 40% to 70%.
Introduction:
• The annual risk of reinfection among
school-age children, adolescents, and
adults is approximately 20%.
• Reinfection illnesses are generally
mild, with most children having only
one infection associated with disease
of the lower respiratory tract.
Pathophysiology:
• The average incubation period of RSVinduced respiratory disease is 5 days.
• Inoculation of upper respiratory tract
epithelial cells occurs via the eye and
nose, with subsequent cell-to-cell
transfer of the virus to the lower
respiratory tract.
Pathophysiology:
• Histopathologic descriptions from
infant autopsy specimens document
infection of the bronchiolar epithelium,
with subsequent epithelial cell
necrosis.
• In addition, there is peribronchiolar
mononuclear infiltration and
submucosal edema.
Pathophysiology:
• As a result of these changes, plugs of mucus
laden with cellular debris are formed,
leading to areas of partial or complete
airway obstruction.
Pathophysiology:
• Hyperinflation occurs following
trapping of air peripheral to the sites of
partial occlusion. Subsequently, with
complete obstruction, multiple areas
of atelectasis develop.
Pathophysiology:
• Often infants who have lower respiratory
tract disease from RSV exhibit pathologic
evidence of both pneumonia and
bronchiolitis.
• In cases of pneumonia, there is an interstitial
infiltration of mononuclear cells, sometimes
accompanied by edema and necrotic
areas that lead to alveolar filling.
Chest film findings in this infant include hyperexpanded lung fields, bilateral interstitial
Darville, T. et al. Pediatrics in Review 1998;19:55-61
Copyright ©1998 American Academy of Pediatrics
Diagnosis:
• Bronchiolitis is a clinical diagnosis. Typically,
infants present with breathing difficulty
associated with coryza
• Less commonly, young infants, especially
those born prematurely, may present with
apnoea before developing the
characteristic cough, tachypnoea and use
of the accessory muscles of respiration.
Clinical Features:
• Nasal obstruction ± rhinorrhoea and an
irritating cough are noticed first.
• After 1–3 days there follows increasing
tachypnoea and respiratory distress. The
chest is often overexpanded.
• Auscultatory signs are very variable: fine
inspiratory crackles are often heard early,
becoming coarser during recovery;
expiratory wheeze is often present, initially
high-pitched, with prolonged expiration.
Diagnosis:
• Respiratory distress may be mild, moderate
or severe.
• Fever of 38.5°C or greater is seen in about
50% of infants with bronchiolitis.
• Apnoea may be the presenting feature,
especially in very young, premature or lowbirthweight infants. It often disappears, to be
replaced by severe respiratory distress
Factors increasing the likelihood of
hospital admission
• History of significant apnoea before
assessment
• Known structural cardiac anomaly,
especially large left-to-right shunt (eg,
ventricular septal defect)
• Known pre-existing lung disease (eg,
cystic fibrosis)
• Chronological age less than 6 weeks
Factors increasing the likelihood of
hospital admission
• Significant prematurity (< 32 weeks)
and/or chronic neonatal lung disease
• Severe degree of respiratory distress or
apnoea
• Significant dehydration
• Hypoxaemia (Spo2 < 93%)
• Re-presentation to the emergency
department within 24
Treatment:
• Prevention of Cross Infection
• Oxygen
• Chest Physiotherapy
• Bronchodilators
• Epinephrine
• Corticosteroids
• Hypertonic Saline
• Antibiotics
Prevention of Cross Infection:
• There is no direct evidence from RCTs that
cohort segregation, handwashing, and use
of gowns, masks, gloves and goggles, in
combination or individually, reduces the
nosocomial transmission of bronchiolitis in
hospitalized infants.
• Three observational studies have found a
lower incidence of RSV transmission in
hospital after the introduction separately of
cohort segregation, handwashing, gowns
and masks, and goggles
Prevention of Cross Infection:
• Combinations of these strategies in one RCT
found no advantage of gowns and masks
over handwashing with gowns and masks,
• Consequently, the most important point to
emphasize to parents and staff is that
frequent adequate hand washing by nursing
and medical staff, other staff and parents
will minimize the risk of cross-infection
Oxygen
• The use of supplemental oxygen therapy
has not been subjected to randomized
controlled clinical trials, but its use is
considered appropriate to overcome
hypoxaemia .
• In general, maintain an Spo2 ≥ 93%
saturation during the acute phase and
during recovery, and accept 90% to 92% if
the child is not distressed and is feeding well
as sufficient for cessation of oxygen therapy
and discharge.
Chest Physiotherapy:
• The Cochrane Library:
• Chest physiotherapy is thought to assist
infants in the clearance of secretions
and decrease ventilatory effort.
Chest Physiotherapy:
• chest physiotherapy using vibration and
percussion techniques did not reduce length
of hospital stay, oxygen requirements, or
improve the severity clinical score in infants
with acute bronchiolitis that are not under
mechanical ventilation, and who do not
have any other co-morbidity
• None of the trials included in this review
reported adverse events
Chest Physiotherapy:
• Many Consensus statements do
recommend the use of physiotherapy
Bronchodilators:
• In viral bronchiolitis, bronchodilators
do not improve oxygen saturation, or
affect rate or duration of
hospitalizations
• Bronchodilators are commonly used in
the management of bronchiolitis in
North America but not in the United
Kingdom
Bronchodilators:
• Cochrane Library:
• Randomized controlled trials (RCTs)
comparing bronchodilators (other than
epinephrine) with placebo in the
treatment of bronchiolitis.
• Twenty-two clinical trials with 1428
infants with bronchiolitis were included
in this review
Bronchodilators:
• There was no improvement in clinical
score for 43% of those treated with
bronchodilators compared to 57% of
those treated with placebo
Bronchodilators:
• There was modest short-term
improvement in clinical scores with the
use of bronchodilators in the
management of mild to moderately
severe bronchiolitis
• there was no statistically significant
improvement in oxygenation overall
Bronchodilators:
• Bronchodilator recipients showed no
improvement in the rate of hospital
admission after treatment as
outpatients
• or duration of hospitalization for
inpatients
Bronchodilators:
• Conclusion: Bronchodilators produce
small short-term improvements in
clinical scores
• Current practice parameter is to use a
trail of bronchodilator, if there is a
clinical improvement, continue its use
else there is no benefit to continue.
Epinephrine:
• Cochrane Library:
• To compare epinephrine versus
placebo and other bronchodilators in
infants less than 2 years of age with
bronchiolitis
Epinephrine:
• Studies were included if they:
– 1) were RCTs comparing epinephrine with
placebo or other bronchodilator;
– 2) involved children less than two years
with bronchiolitis;
Epinephrine:
• There is insufficient evidence to
support the use of epinephrine for the
treatment of bronchiolitis among
inpatients.
• There is some evidence to suggest that
epinephrine may be favourable to
salbutamol and placebo among
outpatients
Corticosteroids:
• Cochrane Library:
• To systematically review the evidence on the
effectiveness of systemic glucocorticoids for the
treatment of infants and young children with acute
viral bronchiolitis.
• The primary outcome of interest was length of
hospital stay (LOS). Secondary outcomes were:
respiratory rate, haemoglobin oxygen saturation,
and hospital admission and revisit rates
Corticosteroids:
• In the pooled analysis of eight trials,
the day three clinical score indicated
no difference between treatment
groups
Corticosteroids:
• Hospital admission rates were
examined in three trials and no
difference was seen between
treatment groups
• Readmission rates were reported in six
studies; with no significant differences
between treatment groups
Corticosteroids:
• The respiratory rate and haemoglobin
oxygen saturation were reported
descriptively in six RCTs; no differences
were found between groups
Corticosteroids:
• No benefits were found in either LOS or
clinical score in infants and young
children treated with systemic
glucocorticoids as compared to
placebo. There were no differences in
these outcomes between treatment
groups; either in the pooled analysis or
in any of the sub analyses.
Corticosteroids:
• Available evidence suggests that
corticosteroid therapy is not of benefit
in this patient group
Antibiotics:
• Cochrane Library:
• To evaluate the effect of using antibiotics,
either routinely or in selected patients, in
infants aged younger than 24 months old,
diagnosed with acute bronchiolitis
compared to placebo to reduce both the
severity and duration of illness.
• This review found no evidence to support
the use of antibiotics for bronchiolitis.
Antibiotics:
• Antibiotics are commonly prescribed
in bronchiolitis, although they have no
action against viruses.
• One small RCT failed to demonstrate
any benefit in hospitalised infants with
bronchiolitis.
Antibiotics:
• The only role for antibiotics is in complicated
bronchiolitis where a secondary bacterial
infection, such as with streptococcus or
staphylococcus, is suspected.
• This is rare, but not easily excluded in a sick
infant with fever, toxicity and significant
opacities on the chest radiograph
Antibiotics:
• Unfortunately, antibiotics are most
frequently prescribed in children with
mild bronchiolitis with minimal chest
radiographic changes, such as partial
right upper lobe collapse, which are
common place in uncomplicated RSV
bronchiolitis.
What is on the horizon?
Nebulized Hypertonic Saline
• Breaks bonds in mucous
• Induces osmotic flow of water into
mucous layer from submucosal cells
• Reduction of edema
• Stimulates ciliary beats by releasing
prostaglandin E2
3% Hypertonic
Saline
• Given nebulized with a
bronchodialator
• Given 3X/day
throughout admission
• Decreases length of stay
by 25%.
• NO side effects or
adverse events
3% Hypertonic Saline in ER
Kuzik et al
• Can it prevent admission to hospital?
• 3 doses neb HS in ER after arrival
• Decrease admission rate by 9% but
study underpowered to reach stat sig.
3% Hypertonic saline….in
progress
“Nebulized Hypertonic saline for Bronchiolitis”
• LA Children’s Hospital and Childrens Hospital at
Oakland
• 3% Hypertonic Saline vs Normal saline
• Up to 3 doses in ER, then Q8h if admitted
• Admission Rate, Length of stay, clinical score
• Feb 2008 – March 2010, n=600
Epinephrine and Steroids!!
“…combined therapy with
dexamethasone and epinephrine may
significantly reduce hospital admissions.”
Suggested Practice
• 4mls 3% HS + 1.5 mg epinephrine
q8h until discharge
• Other meds at physicians discretion
• Exclude
–
–
–
–
Infants >18 months
Previous wheeze
Cardiac or Chronic lung diseases
Critically ill
Summary of Therapies
• Treatment is usually symptomatic
• Isolation
• Humidified oxygen is usually indicated
• Ensure patients are well hydrated
• Chest physio is of no proven benefit
• Saline nose drops may be of value
Summary of Therapies
• Trial of bronchodilators may improve
wheezing
• Epinephrine has shown some benefits
• Corticosteroids are not indicated
• Antibiotics are not useful
• 3% Normal Saline of value
• Ventilatory assistance should be
considered for those with increasing
respiratory distress
Which of the following conditions puts an infant at higher risk for more
severe disease?
a) Prematurity
b) Congenital Heart Disease
c) Down Syndrome
d) All of the above
Which of the following are
considered “Routine” orders for
an infant being admitted with
bronchiolitis?
a) Chest Xray
b) Amoxil
c) Oxygen and fluids as needed
d) Ventolin q4h
Which of the following treatments
may improve outcomes for
bronchiolitis patients?
a) Ventolin
b) Hypertonic saline (3%)
c) Amoxil
d) Combination of Epinephrine and
Dexamethasone.
When is it Asthma?
When is it Asthma?
Virology:
• RSV is an enveloped, single-stranded
RNA virus. Two glycosylated surface
proteins, the attachment (G) and
fusion (F) proteins, are essential for RSV
to infect cells
Virology:
• This electron
micrograph of
respiratory syncytial
virus (RSV) illustrates
five virions budding
from an infected
cell
SPREAD OF INFECTION
• RSV spreads easily from person to person
through respiratory secretions. Spread within
families is very high.
• RSV is a major nosocomial threat on
pediatric wards, causing appreciable
morbidity.
• The two primary modes of transmission for
RSV include direct contact with large
droplets of secretions and self-inoculation
by touching contaminated objects.
SPREAD OF INFECTION
• Transmission by small-particle aerosol
is not significant; thus, the risk of
acquiring infection decreases with
increasing distance from the patient.
• RSV-infected nasal secretions remain
infectious on countertops for more
than 6 hours.
SPREAD OF INFECTION
• RSV can be recovered from rubber gloves
for 1 hour and 30 minutes, from gowns for 30
minutes, and from hands for 25 minutes.
• Thus, RSV can survive for extended periods
in the hospital environment, increasing the
risk for infectious transfer from fomites to
hands and then to the eyes and nose of a
susceptible individual. The eyes and nose
appear to be the primary entry sites for RSV;
the mouth is an insensitive route of
inoculation.
SPREAD OF INFECTION
• RSV frequently is shed for prolonged
periods, which increases its contagious
nature.
• In a study of infants hospitalized for
RSV infection, the mean duration of
shedding was 6.7 days, with a range of
1 to 21 days.
SPREAD OF INFECTION
• Viral shedding from asymptomatic
patients does occur.
• In the immunocompromised host, viral
shedding can extend beyond 6 weeks.
SPREAD OF INFECTION
• Because immunity to this virus is shortlived, there is always a large number
of susceptible individuals.
• Hospital nursery units, child care
centers, and other institutions are at
high risk for RSV outbreaks.
SPREAD OF INFECTION
• Transmission among infants may not
be as important as transmission
between infants and staff.
• Visitors are another potential source of
spread.