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Pico journal article presentation Maria Nguyen. BACKGROUND. Asthma is a common, potentially life-threatening condition Accounts for 2 million pediatric ED visits annually 500, 000 hospitalizations ~ $ 6 billion in total healthcare expenditures on an annual basis - PowerPoint PPT Presentation
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Pico journal article presentationMaria Nguyen
BACKGROUND Asthma is a common, potentially life-threatening condition
Accounts for 2 million pediatric ED visits annually
500, 000 hospitalizations
~ $ 6 billion in total healthcare expenditures on an annual basis
high morbidity and mortality associated with status asthmatics
HELIUM Helium was first isolated from atmospheric air in 1895
Barach first described clinical use of heliox 1935› Heliox is less dense than air › improves flow turbulent laminar flow› decrease work of breathing
Heliox therapy in asthmatics› improved oxygenation› Increase carbon dioxide elimination› Increase expiratory flow› Decrease work of breathing› Enhanced delivery of aerosolized medications to the
peripheral alveoli
Structured Clinical Question
Patient: Pediatric Patients with moderate to severe asthma requiring albuterol
Intervention: albuterol nebulized in heliox
Comparison: Albuterol in oxygen/air
Outcome: › Clinical improvement› Admission rate› Duration of hospitalization
Finding the Evidence Search: Pubmed Key words: Asthma, heliox nebulized albuterol/b-2 agonist Limit the search to:
› a. Birth to 18 years› b. English language› c. Randomized Clinical Trial› d. Humans
Results: 43 3 studies:
› Helium/oxygen-driven albuterol nebulization in the treatment of children with moderate to severe asthma exacerbations: A randomized, Controlled Trial
› Albuterol nebulized in heliox in the initial ED treatment in pediatric asthma: a blinded, randomized controlled trial
› Helium/oxygen-driven albuterol nebulization in the management of children with status asthmaticus: A randomized, placebo-controlled trial
ObjectiveSingle centered (ED of an urban tertiary care children’s hospital)
Time: between October 2001 to May 2002
Randomized, blind controlled trial
Evaluate the efficacy of heliox versus oxygen in driving continuous albuterol nebulization in children with moderate to severe asthma
Inclusion Criteria Ages 2 to 18 years Pulmonary index (PI) score ≥ 8 Diagnosis of asthma consent
Exclusion Criteria Presence of cyanotic heart disease concurrent bronchiolitis (+ RSV) lobar pneumonia on CXR Croup foreign-body aspiration Pre-existing chronic lung disease Underlying chronic medical conditions Pregnancy/nursing Intolerance of nonrebreather face mask Use of oral or parenteral corticosteroids within the preceding 72 hours
Study
Intervention
Albuterol (continuous) using
PI score was performed at 30 min intervals by a blinded investigator
Study continued until discharge or for 240 minutes
Treatment:
Heliox (70:30)
Control:
Oxygen (100%)
Statistical Analysis Clinical improvement in PI defined as an
decrease of ≥ 2 units over study time
Sample size calculated › 2 units were considered to the minimum
relevant difference› alpha: 0.05› power 80%
N: 30 with 15 in each group
Results
ResultsThe mean change in PI score from baseline to 240 minutes
Primary Outcome
At 125 minutes, the heliox group showed a clinically significant absolute mean PI improvement compared with
the oxygen group (p< 0.05).
A clinically significant difference of absolute mean PI scores (p < 0.01) was sustained at 150, 180 and 240 minutes.
Secondary Outcome
67% patients in heliox group were discharged from the ED compared with 33% in the oxygen group (P = 0.07)—not statistically significant
73% patients in the heliox group were discharged home from hospital in < 12 hours compared with 33% in the conventional group (P < 0.05)
0
10
20
30
40
50
60
70
80
ED discharge Discharged < 12 hours after admission
perc
enta
ge (%
)
Heliox Oxygen
CONCLUSION
Continuously nebulized albuterol delivered by heliox was associated with a greater
degree of clinical improvement compared with that delivered by oxygen among
children with moderate to severe asthma
Benefit Randomized
Blinded
Follow up was completed:› Telephone f/u at 24-hour and 7 day (none
returned to ED or had unscheduled visit to PMD
Drawbacks Lack of blinding by the patient may have affected the PI score
› patient’s sense of dyspnea can be affected by knowing › this knowledge can in turn influence respiratory rate and retractions affect PI
score
Lack of blinding for the attending physician who determined admission, ED discharge and hospital discharge
Albuterol 15 mg/hour of continuous albuterol to all patients (weight based: 0.45 mg/kg/hour )› 4 in heliox and 5 in oxygen group received > than the dose recommended
Not adequately powered for secondary outcomes Adverse effects not measured Use of face mask for delivering aerosolized medications may limit
applicability to younger-aged children who may not tolerate face masks
Objective Single-centered September 1998 to Nov
1998
Primary Outcome› difference in a
modified dyspnea index b/w the 2 groups after 10 and 20 minutes of continuous nebulized albuterol
Secondary› Endotreacheal
intubation in the ED› Admissions to the
hospital
Inclusion Criteria Age 3 to 16 years
previous hx of asthma
a modified dyspnea index of ≥ 4
Exclusion criteria Hx of any other chronic pulmonary disease
Suspected foreign body in the airways
pulmonary edema
Chronic cardiac diseases
CNS disease
Genetic disorder
Immunocompromised states
Method all patients received:
› 3 doses of aerosolized albuterol› IVF at maintenance› 2mg/kg IV methylprednisolone
continuous albuterol therapy (0.45 mg/kg, maximum dose 15 mg/hr)
Modified dyspnea index score was performed at 10 and 20 minutes after treatment
Treatment:
30% O2: 70% helium
Control
30% O2:70% air
Statistical analysis Sample size:
› Detect difference in the modified dyspnea index ≥ 2
› alpha 0.05 › Power: 0.8
N: 17 in each group (total of 34)
Results: Baseline Characteristics
No statistical difference in baseline characteristics b/w the study groups.
Results: Primary Outcome
no significant difference in the median modified dyspnea index scores were noted b/w the study
groups
Results: Secondary Outcomes
0102030405060708090
Intubation Rate of Admission
Perc
ent (
%)
Heliox Oxygen
None of the study subjects were intubated during their ED stay
Rate of admission was 60% in heliox group and 81% in the oxygen group (p = 0.181)
Conclusion
Albuterol nebulized with heliox offered no clinical benefit over standard therapy in
the initial treatment of moderately severe asthma in the ED
Advantages Randomized
Blinding was maintained › children did not speak with the study
investigator assigning the modified dyspnea index scores
› tanks remained covered during assessment
Adequately powered to detect changes for primary outcome
Drawbacks Low powered study
Short follow-up › Only 20 minutes› After only 1 dose of a continuous albuterol
Adverse effect not addressed
Objective Primary outcome:
› Effect of heliox-powered albuterol therapy on hospital length of stay and clinical status in children with moderate to severe status asthmatics
Secondary outcome› Length of time required to reach a CAS ≤ 3› Adverse event rate› PICU length of stay
Study Design Prospective
Randomized
Placebo-controlled trial
single centered
May 2006 to December 2007
Inclusion Criteria Age 2 to 21 years
Hx of asthma
Modified Becker Clinical Asthma Score (CAS ≥ 3)
Admission to PICU or asthma ward
Exclusion Criteria need for invasive or non-invasive
mechanical ventilation
Impending respiratory failure (PaCO2 > 60, AMS)
Need for supplemental oxygen with an FiO2 ≥ 0.4 to maintain oxygen saturations > 90%
Intervention
Albuterol (continuous or intermittent) using
CAS score was performed at 4 hour intervals by a blinded investigator
Study continued until participants were discharged
Treatment:
Heliox (70:30)
Control:
Air/oxygen (70:30)
Statistical Analysis Sample size: N 348 (174 participants in
each group)
› 0.5 day reduction in hospital length of stay› power of 80%› Alpha 0.05
P value ≤ 0.05 is considered significant
Results
No significant baseline clinical or demographic differences between the 2 study groups
Primary OutcomeThere were no significant difference in
CAS between the two study groups at any time point after randomization
Primary OutcomeHospital length of stay was not different b/w the 2 groups
Secondary OutcomeThere were no difference between groups in the time to CAS < 3
No difference b/w the groups in CAS score at 24-hour and at the end of the study
Secondary Outcomes: PICU subgroups
No differences in time to CAS < 3, PICU length of stay, duration of treatment,
or time of discharge eligibility
Secondary Outcomes: Adverse Events
No difference in the rates of adverse events b/w the 2 groups
Conclusion
Heliox-powered nebulized albuterol therapy does not reduce the duration of hospitalization nor hasten the time to clinical improvement for children admitted to the hospital with moderate to severe status asthmaticus
Advantages Largest pediatric trial involving heliox-
powered albuterol in the treatment
Looks at hospitalization duration
PICU subset
assessment of CAS performed by blind investigator
Drawbacks Excluded patients with CAS < 3
inpatient (may have been CAS ≥ in ED)
Underpowered (low enrolment)
Healthcare team involved in therapeutic decision-making as well as transfer and discharge assessments were not blinded
SUMMARY
albuterol nebulized with heliox offered no clinical benefit over standard therapy in the initial treatment of moderately severe asthma in the ED (2nd study)
Continuously nebulized albuterol delivered by heliox was associated with a greater degree of clinical improvement compared with that delivered by oxygen among children after the initial ~ 2 hours (1st study)
Heliox-powered nebulized albuterol therapy does not reduce the duration of hospitalization nor hasten the time to clinical improvement for children admitted to the hospital with moderate to severe status asthmaticus (3rd study)
FINAL SUMMARY
Based on these data, heliox-powered albuterol cannot be recommended for regular use in the treatment of children with moderate to severe
asthmaticus