Thrombectomy, the pituitary, the aneurysm and the carotid clamp. Three of the four turn on a quantity that serves two masters, and one turns on believing a large body of consistent data for the wrong reason.
01
What this is
no new material
**No new material. Harder questions.**
Day 05 was a lesson in causal inference wearing a stroke costume: the cohorts were right about the association and wrong about what produced it. Day 06 put a carotid artery within nine millimetres of the surgeon's instrument and the sodium problem a week past discharge. Day 07 collapsed transmural pressure and cerebral perfusion pressure into one number pulled in two directions. Day 08 rested an entire operation on a collateral supply most patients do not have intact.
The through-line is that a single quantity often serves two purposes at once, and that the intervention which helps one can be the intervention that harms the other. Hyperventilating an unsecured aneurysm is the cleanest example in the rotation.
Answer first, then read. Checking the day before answering turns retrieval
practice into rereading, and the two feel identical while you are doing them.
03
The questions
9 of 10 application or analysis
Item 1Analysis Neuro 2 · Week 2
Observational studies consistently showed worse outcomes with general anaesthesia for thrombectomy. Three randomised trials found no disadvantage. What was wrong with the observational conclusion?
Item 2Application Neuro 2 · Week 2
What did the randomised thrombectomy trials hold constant, and why does that matter for how you run one of these cases?
Item 3Recall Neuro 2 · Week 2
How far is the internal carotid artery from the pituitary gland, and what follows for the anaesthetic?
Item 4Application Neuro 2 · Week 2
A patient is 36 hours after transsphenoidal surgery with polyuria and a sodium of 148. What is happening, and what governs treatment?
Item 5Analysis Neuro 2 · Week 2
Why is the sodium problem that readmits a transsphenoidal patient not the one you manage in theatre?
Item 6Analysis Neuro 2 · Week 2
A good-grade patient with an unsecured aneurysm has a tight brain. A colleague suggests hyperventilation. What is the objection?
Item 7Analysis Neuro 2 · Week 2
Which patient tolerates a greater reduction in blood pressure during aneurysm surgery, and what explains it?
Item 8Analysis Neuro 2 · Week 2
Why is raising the blood pressure during carotid cross-clamping a weaker intervention than it appears?
Item 9Application Neuro 2 · Week 2
What is the correct order of clamping and declamping in carotid endarterectomy, and what is the reasoning?
Item 10Analysis Neuro 2 · Week 2
No intraoperative monitor for carotid surgery matches awake testing. What is the correct conclusion?