Respiratory and Thoracic Emergencies
Core concepts
Master the recognition and stepwise management of acute severe asthma (silent chest, exhaustion, rising PaCO2 are ominous), COPD exacerbation with controlled oxygen targeting, and the distinction between type 1 and type 2 respiratory failure. Understand tension pneumothorax as a clinical diagnosis requiring immediate needle decompression before imaging, and the difference between simple, open, and tension pneumothorax. Pulmonary embolism risk stratification (Wells, PERC, sPESI) and the role of D-dimer in low-probability patients is high-yield. Also cover acute pulmonary oedema, pneumonia severity scoring, and upper airway obstruction.
Traps
Examiners test the normal or rising PaCO2 in asthma as a sign of impending arrest, not reassurance. Another trap is ordering a chest radiograph before decompressing a tension pneumothorax. In COPD, uncontrolled high-flow oxygen can worsen hypercapnia. D-dimer is useless in high-probability patients and in pregnancy - go straight to imaging.
Rule of thumb
In any breathless patient with unilateral absent breath sounds and haemodynamic compromise, decompress first, image later. In asthma, a silent chest is a surgical-level emergency, not a sign of improvement.
Worked example
A 24-year-old asthmatic with a peak flow 30% predicted, drowsiness, and PaCO2 of 6.5 kPa: this is life-threatening asthma - give back-to-back bronchodilators, IV magnesium, steroids, and call for critical care; do not discharge.