FRCA Primary revision tips

Worked single-best-answer questions, each with the reasoning written out. Every one gives the underlying science the way a textbook would, and then the practical part: what to read off the stem first, how to eliminate options, and what pattern the paper is testing.

Why does an interscalene block make patients breathless? — FRCA Primary: why an interscalene block causes phrenic nerve palsy and breathlessness. Worked SBA on brachial plexus anatomy with exam tips.
Potency vs efficacy: what the dose-response curve really tells you — FRCA Primary: potency vs efficacy on the dose-response curve. Worked SBA question with textbook explanation and exam tips.
Why is the pulse oximeter normal in severe anaemia? — FRCA Primary: why SpO2 is normal in severe anaemia, and how content differs from saturation. Worked SBA with explanation and exam tips.
What does a sudden loss of the capnography trace mean? — FRCA Primary: what a sudden loss of the capnography trace means, and how to read the waveform. Worked SBA with explanation and exam tips.
What shifts the oxygen dissociation curve to the left? — FRCA Primary: what shifts the oxygen dissociation curve left, and what P50 means. Worked SBA with textbook explanation and exam tips.
Aortic stenosis on the pressure-volume loop: what changes and why — FRCA Primary: aortic stenosis on the left ventricular pressure-volume loop. Worked SBA on the cardiac cycle with explanation and exam tips.
Why can a patient breathe with a train-of-four count of two? — FRCA Primary: why the diaphragm recovers from rocuronium before the hand. Worked SBA on muscle sensitivity to neuromuscular blockers.
Which patient factors increase MAC, and which lower it? — FRCA Primary: which factors increase MAC and which lower it. Worked SBA on inhalational agent potency with explanation and exam tips.
Why does lidocaine work faster than bupivacaine? — FRCA Primary: why lidocaine has a faster onset than bupivacaine. Worked SBA on local anaesthetic pKa, with explanation and exam tips.