Respiratory and Critical Care Emergencies
Domain focus
The Respiratory and Critical Care Emergencies domain tests severe asthma, COPD, ARDS, pulmonary embolism, and mechanical ventilation. The board emphasizes when to intubate and how to avoid ventilator-induced injury.
Core rules
- Severe asthma: continuous inhaled SABA, ipratropium, systemic corticosteroid, magnesium; consider early intubation for fatigue or silent chest. Avoid sedation without airway control.
- COPD exacerbation: controlled oxygen to target 88–92%, bronchodilators, steroids, antibiotics if infection; NIV for acidosis.
- ARDS: lung-protective ventilation with tidal volume 6 mL/kg predicted body weight, plateau pressure <30 cm H2O, adequate PEEP, permissive hypercapnia.
- Pulmonary embolism: risk stratify; unstable patient may need thrombolysis or embolectomy; heparin for stable.
- Do not use high tidal volumes or high plateau pressures.
Worked example
A 24-year-old asthmatic is exhausted, has a silent chest, and PaCO2 is rising. Reasoning: a normal or rising CO2 in severe asthma signals fatigue, not improvement. Prepare for rapid sequence intubation, give ketamine, continue bronchodilators via ventilator, and monitor for dynamic hyperinflation with low respiratory rate and long expiration.
Traps
Relying on oxygen saturation alone in asthma, missing pneumothorax after barotrauma, and using high tidal volumes in ARDS are common. In COPD, excessive oxygen can worsen hypercapnia.