You decide on the one big most acute medical need, That’s how. You don’t get to play this game of the 80-year-old only has 10 more years left so they’re less important than the 40-year-old..
You don’t get to use who you think is more valuable is a metric. You can only use medical needs. As much as that pisses off collectivist jerks.
it’s not about age it’s about chances of survival. If the 80 year old also has, diabetes and liver failure that means that the chances they will come off the vent alive are small, whereas the 40 yr old without diabetes and liver failure has a better chance of survival.
In other words, if you put the 80 year old ( with above conditions there is a high chance even with ventilator support they will still die) on the ventilator instead of the 40 year old then it’s highly likely they both die. Just getting put on the ventilator doesn’t guarantee survival.
That’s not how triage works — if you think the 80 year old is less likely to survive than the 40 year old, you chose the 40 year old