Pulmonology
Pulmonology tests spirometry interpretation, severity assessment in asthma and COPD, pneumonia and PE pathways, pleural disease, and arterial blood gas reasoning. The recurring theme is objective severity: numbers decide admission, oxygen targets, and escalation.
Core rules
- Spirometry: post-bronchodilator FEV1/FVC <0.70 defines persistent airflow limitation (COPD); asthma shows variable limitation, reversibility >12% and 200 mL, or a positive challenge.
- Acute asthma: severity from speech, PEF, SpO2 and silent chest; give oxygen 94–98%, SABA, ipratropium, systemic steroid; add IV magnesium for severe attacks; antibiotics are not routine.
- COPD exacerbation: controlled oxygen 88–92%, nebulized bronchodilators, prednisolone 5 days, antibiotics if increased sputum purulence or ventilatory support; NIV for pH 7.25–7.35 with hypercapnia.
- Community-acquired pneumonia: assess severity with CURB-65; antibiotics according to setting and local guidance; reassess at 48–72 hours; follow-up imaging if persistent.
- PE: Wells or Geneva score, age-adjusted D-dimer, CTPA; sPESI identifies low-risk patients; anticoagulate.
- ABG: calculate A–a gradient; distinguish type 1 from type 2 respiratory failure and assess compensation.
Worked example
A 24-year-old woman has acute wheeze after a URTI, PEF 45% predicted, speaks in phrases, and SpO2 92%. This is severe acute asthma: oxygen to 94–98%, back-to-back SABA plus ipratropium, prednisolone 40–50 mg, and IV magnesium. Reassess frequently; avoid sedation and routine antibiotics. A normal ABG does not exclude severe asthma because hyperventilation lowers pCO2 early.
Traps
- Targeting high oxygen in COPD.
- Giving antibiotics for every wheeze.
- Missing PE when the chest X-ray is normal.
- Failing to escalate a silent chest.
- Using spirometry during an acute exacerbation to diagnose asthma.