Respiratory Medicine Flashcards
6 cards from real MRCP PART 1 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Respiratory Medicine flashcards as text
A patient is intubated and ventilated for ARDS. Which ventilation strategy reduces mortality?
Answer: Lung-protective ventilation (tidal volume 6 mL/kg, plateau pressure <30 cmH2O)
The ARMA trial demonstrated that lung-protective ventilation with low tidal volumes (6 mL/kg ideal body weight) and a plateau pressure below 30 cmH2O reduces mortality in ARDS compared to high tidal volume ventilation by minimising ventilator-induced lung injury.
Which of the following is the most common cause of a spontaneous pneumothorax in a tall, thin young man?
Answer: Idiopathic rupture of a subpleural bleb
Primary spontaneous pneumothorax typically occurs in tall, thin young men and is caused by rupture of subpleural blebs (small air-filled sacs) at the lung apex. This is idiopathic — no underlying lung disease is identified. Secondary spontaneous pneumothorax occurs in those with underlying lung disease.
A patient with asthma fails to respond to salbutamol and ipratropium nebulisers. Which additional treatment should be given for a life-threatening attack?
Answer: IV magnesium sulphate 1.2–2g over 20 minutes
IV magnesium sulphate (1.2–2g over 20 minutes) is indicated for life-threatening asthma that fails to respond to initial bronchodilator therapy. It causes bronchial smooth muscle relaxation by inhibiting calcium-mediated bronchoconstriction. This is a BTS/SIGN guideline recommendation.
In a patient with type 2 respiratory failure (low PaO2 and raised PaCO2), what oxygen delivery target is recommended?
Answer: SpO2 88–92% with controlled low-flow oxygen
In type 2 respiratory failure (hypercapnic), the target SpO2 is 88–92%. These patients have chronic CO2 retention and may rely on hypoxic drive for ventilation. High-flow oxygen can suppress this, worsening hypercapnia. Controlled oxygen via a Venturi mask maintains the lower target safely.
What is the mechanism by which montelukast acts in asthma?
Answer: Leukotriene receptor antagonism
Montelukast is a leukotriene receptor antagonist (LTRA) that blocks cysteinyl leukotriene receptors (CysLT1). Leukotrienes are inflammatory mediators that cause bronchoconstriction, mucus secretion, and airway oedema. Blocking them reduces these effects in asthma and allergic rhinitis.
A chest physician suspects mesothelioma in a patient with a unilateral pleural effusion and a history of asbestos exposure. Which investigation is most likely to confirm the diagnosis?
Answer: CT-guided or thoracoscopic pleural biopsy
Mesothelioma diagnosis requires histological confirmation from pleural tissue. Pleural fluid cytology has low sensitivity for mesothelioma. CT-guided biopsy or thoracoscopy with directed biopsies provides histological tissue with adequate yield for diagnosis and subtyping (epithelioid, sarcomatoid, biphasic).