Respiratory and Thoracic Emergencies
This domain covers acute asthma, COPD exacerbation, pulmonary embolism, pneumothorax, pleural disease, respiratory failure, and arterial blood gas interpretation. The exam tests rapid severity assessment and safe oxygen and ventilation strategies.
Core rules
- Asthma: assess speech, effort, air entry, and silent chest. Give inhaled short-acting beta-agonist and ipratropium, systemic corticosteroids, and magnesium for severe cases. A silent chest is imminent failure.
- COPD: controlled oxygen to target saturation, bronchodilators, corticosteroids, and noninvasive ventilation for acidotic exacerbation unless contraindicated.
- Tension pneumothorax is clinical: hypotension, unilateral absent breath sounds, distended neck veins. Decompress immediately without waiting for imaging.
- Pulmonary embolism: use pretest probability, D-dimer in low/intermediate risk, and CT pulmonary angiography when indicated. High-risk PE with shock needs reperfusion.
- Type 1 respiratory failure is hypoxaemia; type 2 is hypercapnia. Noninvasive ventilation reduces intubation in selected COPD exacerbations.
Worked example
A 24-year-old asthmatic cannot complete sentences and has minimal air entry. Oxygen saturation is 89%. This is life-threatening asthma. Give oxygen, nebulised salbutamol and ipratropium, IV corticosteroids, and IV magnesium; prepare for intubation if fatigue or worsening hypercapnia develops.
Traps
- Do not rely on pulse oximetry alone in severe asthma; normal saturation can accompany dangerous fatigue.
- Do not delay needle decompression for a chest radiograph in tension pneumothorax.
- Do not give high-flow oxygen indiscriminately in COPD with chronic hypercapnia; titrate to target.
- Remember that pulmonary embolism can present with syncope or unexplained tachycardia.