Asthma — Assessment, Key Points — Clinical Pathway: Emergency

Asthma Clinical Pathway – Emergency Department

Asthma Assessment – Key Points

Variability
  • Asthmatic children show acute airway obstruction differently depending on many factors, including age and baseline lung function.
  • One set of criteria cannot define asthma severity accurately across this wide spectrum of disease.
  • Assignment of acute asthma severity is based on an overall integrated assessment of available signs, symptoms and (if able) lung function.
Spirometry/Peak Flow
  • Pulmonary function tests are objective measures to directly assess airway obstruction.
  • Valid measurement requires good effort by the patient and should be interpreted based on baseline lung function (when available) or a value predicted by height.
PASS Pediatric Asthma Severity Score (range 0-6, see below) includes key exam elements (wheezing, work of breathing, prolongation of expiration) that correlate with the overall assessment to follow trends over time.
Pulse Oximetry
  • Assessment for hypoxemia is important, as it may not be apparent on physical examination.
  • It most often reflects ventilation-perfusion mismatch due to mucus plugging or bronchospasm, which may not correlate with asthma severity. This effect may be temporarily worsened by bronchodilator therapy.
  • Decisions about oxygen therapy should be based on overall saturation trends. Continuous pulse oximetry should be withdrawn as patients improve.

Determine Severity Level of Asthma Exacerbation

Assignment of acute asthma severity is based on an overall integrated assessment of available signs, symptoms and (if able) lung function.

  Mild Moderate Severe Respiratory Arrest Imminent
Key Exam Elements (PASS)
Wheezing None or mild (0)
None or end of expiration only		 Moderate (1)
Throughout expiration		 Severe(2)
Inspiratory/expiratory or absent due to poor air exchange		 Diminished due to poor air exchange
Work of Breathing None or mild (0)
Normal or minimal retractions		 Moderate (1)
Intercostal retractions		 Severe (2)
Suprasternal retractions, abdominal breathing		 Tiring, inability to maintain work
of breathing
Prolonged Expiration None or mild (0)
Normal or minimally prolonged		 Moderate (1) Severe (2) Severely prolonged
Other Exam Elements
Breath Sounds/Aeration Normal Decreased at bases Widespread decrease Absent/minimal
Symptoms
Breathlessness With activity or agitation
  • While at rest
  • For infants:
    • Soft or shorter cry
    • Difficulty feeding
    • Prefers sitting
  • While at rest
  • For infants:
    • Stops feeding
    • Sits upright
  
Talks In Sentences Phrases Words  
Alertness Alert May be agitated Agitated Drowsy, confused
Measurements
Pulse Oximetry > 94% Variable Variable Variable
PEF
% of predicted
by height		 ≥ 70% 40-69% < 40%  

Guide to Respiratory and Heart Rates in Awake Children

Age Normal Respiratory Rate
(per Minute)		 Normal Heart Rate
(per Minute)
< 2 mos < 60 < 160
2-12 mos < 50 < 160
1-2 yrs < 40 < 120
2-5 yrs < 40 < 110
6-8 yrs < 30 < 110