Upper-airway dominant patterns
Anaphylaxis
Rapid edema and bronchospasm can combine to threaten airway, breathing, and circulation. Early epinephrine plus airway support is central.
Foreign-body airway obstruction
Acutely blocks airflow and can progress to complete obstruction. Immediate recognition and protocol-based response are time-critical.
Epiglottitis and severe supraglottic infection
Can cause rapidly progressive upper-airway obstruction. Modern incidence changed after H. influenzae type b vaccination, but severe cases still occur and require urgent specialist management.
Lower-airway dominant patterns
Acute asthma exacerbation
Lower-airway inflammation and bronchoconstriction reduce airflow, typically with expiratory wheeze and prolonged exhalation. Severe cases may show minimal air movement, which is a high-risk sign.
COPD exacerbation
Airflow limitation can acutely worsen from infection, inflammation, or other triggers. Management priorities include oxygenation, ventilation support when needed, and cause-directed therapy.
Mixed or evolving patterns
Many patients present with overlap (for example infection plus bronchospasm). Reassess frequently and update the working diagnosis based on trajectory, not a single exam snapshot.
Practical diagnostic habit
Ask on every reassessment:
- Is obstruction site clearer now?
- Is oxygenation better, worse, or unchanged?
- Is ventilation better, worse, or unchanged?
- Does current treatment still match physiology?
For external guidance links, see References and guidelines.