What is the lifetime prevalence of asthma in Canadian children?
11-16%
What are the most common asthma exacerbation triggers?
- Viral resp tract infections
Other triggers include: - Allergen exposure
- Suboptimal asthma control at baseline
What are the ED objectives for management of actuate asthma exacerbations?
- Assessment of severity
- Medical intervention
- Appropriate disposition
- Proper follow up
What are the clinical features of a mild asthma exacerbation?
- Normal mental status
- Normal activity/exertional dyspnea
- Normal speech
- Minimal IC retractions
- Mod wheeze
- SpO2 >94% RA
- Peak flow >80% personal best
What are the clinical features of a moderate asthma exacerbation (7)?
- Normal mental status/might looked agitated
- Decreases activity or feeding (infant)
- Speaks in phrases
- Subcostal and IC retractions
- Loud pan expiratory and inspiratory wheeze
- SpO2 91-94% RA
- Peak flow 60-80% personal best
What are the clinical features of a severe asthma exacerbation (6)?
- Usually agitated
- Decreases activity or stops feeding (infant)
- Speaks in words
- Significant resp distress, all accessory muscle involved, possible nasal flaring or paradoxical thoraco-abdo movement
- Wheeze audible without stethoscope
- Peak flow
What are the clinical features of impending resp failure (7)?
- Drowsy or confused
- Unable to eat
- Unable to speak
- Marked resp distress at rest with nasal flare, all accessory muscle use and thoraco-abdo breathing
- Silent chest
- SpO2
What SpO2 sat is associated with a higher morbidity and risk of hospitalization in asthma exacerbation?
SpO2 of 92% or less on presentation
A focused hx in an asthma exacerbation should include?
- previous medications
- Previous life threatening events
- Admissions to ICU
- Intubations
- Deterioration while on systemic corticosteroids
A focused px exam in an asthma exacerbation should include…?
- Severity of airway obstruction
- Accessory muscle use
- A/E bilaterally
- Wheezing
- LOC/alertness
- Ability to speak in full sentences
- Activity level
List the clinical features of cerebral hypoxemia
- Mental agitation
- Drowsiness
- Confusion
An ominous sign of insufficient gas exchange is….?
Silent chest
When is a chest X-ray indicated in an asthma exacerbation?
- Suspected complications ie pneumo
- Bacterial pneumonia
- FB
- Failure to improve despite maximal conventional tx
Otherwise leads to over dx of pneumonia
When is a blood indicated in an asthma exacerbation?
No clinical improvement despite max therapy
Signs of impending respiratory failure include…?
- Silent chest
- Normal cap CO2 despite persistent resp distress
- Altered LOC
- Central cyanosis
What is the preferred method of bronchodilator admin and why?
MDI with spacer, because it’s less likely to evoke tachycardia and hypoxemia then nebs (even if on O2, exception is severe impending resp failure)
Side effects of salbutamol include…?
- Tachycardia
- Hyperglycaemia
- Hypokalemia
There is a risk of cardiac arrhythmia in adults, but no evidence in kids
What is the benefit of antocholinergics in asthma and when should they be used?
- Better lung function than beta 2 agonists alone
- Reduce hospital admission.
Only if used in 1st hour, no evidence after this (Q 20 min for 1st hour)
What is the benefit of systemic steroids (PO/IV) in asthma and when should they be used?
- Reduce hospital admissions
- Reduce risk of relapse after initial tx
- Earlier d/c from hospital
Should be used in mod to severe exacerbations
What is the benefit of MgSo4 in asthma and when should it be used?
Used in severe acute asthma (mod to severe) with incomplete response to conventional tx in the 1st 1-2 hrs
- Improves resp function
- Decreases hospital admissions
What is the SE in of MgSo4?
- Hypotension
- Bradycardia
So monitor VS
What is the benefit of IV salbutamol in asthma and when should it be used?
- Improve pulm function and gas exchange
Use in severe asthma of no response to other tx
When should IV aminophylline or Heliox be used?
In ICU with severe exacerbation that have failed to improve despite max tx (IV steroids, continuous inhaled B2 agonist)
List complications of intubation in acute asthma exacerbation?
- Pneumo
- Impaired venous return
- Cardiovascular collapse due to increased intra thoracic pressure
