It often can be difficult to prove, as many variables.
And much depends on the skill and comfort of the doc with each modality.
1cc of 0.5 isobaric bupiv and 50mcg of pro is extremely stable for sick elderly.
Can you do LMA or geta well, sure, but I find it's much more prone to hypotension. Maybe others do things to mitigate that..pre induction neo, ephedrine or use etomidate or ketamine, etc
Hard to mess up 1cc of bupiv spinal. Not that hard to get significant hypotension if you overdo the induction for GA. But pros and cons to each approach and of course, different ways to counter the cons of each
Ga is less hassle