Asthma (OSCE)

Clinical Assessment of Asthma

ABC, Vitals

• SaO2

Inspection

Fingers

• cyanosis

Chest

• ↑AP diameter (barrel chest)
• asymmetry of shape and movement

Work of Breathing

• RR, HR
• POSTURE (tripoding)
• level of comfort, speaking full sentences, diaphoresis
• accessory muscle use (SCM, shoulder elevation), nasal flaring, pursed lips

Signs of RESPIRATORY EXHAUSTION or impending FAILURE

• ↓ LOC, ↓ amplitude of pulse
• central cyanosis (tongue, oral mucosa)
• intercostals, subcostal, and supraclavicular indrawing
• pulsus paradoxus (> 18 mm Hg drop with inspiration suggests very severe asthma)
• paradoxical movement of the diaphragm

Palpation

• tracheal tug
• symmetrically ↓ chest expansion
• ↓ tactile fremitus (due to hyperinflation)

Percussion

• hyperresonance - percuss anteriorly and posteriorly, compare L and R
• ↓ diaphragmatic excursion (normal is 5 - 6 cm)
  • inferior displacement of diaphragm due to hyperinflation

Auscultation

• listen to each lobe, compare L and R
  • major fissure: T3 posteriorly → 4th ICS MAL → 6th rib MCL
  • minor fissure: 5th ICS MAL → 4th ICS parasternal
• ↓ AE
• prolonged expiratory phase
  • forced expiration with bell on trachea (normal < 5 s, abnormal > 6 s)
• wheezing
  • may be absent in severe asthma
• consolidation
  • suggests pneumonia as trigger for acute attack

Special Tests

• peak expiratory flow rate (PEFR): normal male 600, female 400, sick < 150
• PFT - obstructive pattern (↓ flow rates, ↑ volumes)
• ABG - pH < 7.3, PO2 < 60, PCO2 > 45