No different than if you said "We're going to see them for a long weekend on Feb 22". Leaving in 2 min or leaving in 2 weeks, packed is packed
From going through it with my dad & grandmother, 6 hr drive away a few things to consider....
1. Hospitals are cold. Hospitals are hot. - the room you're sitting in with someone will be the opposite of how you dressed.
2. Hospitals are noisy. Esp if you are staying bedside overnight. Seems like EVERY room has something alarming all night long. earplugs, noise canceling headphones.
3. Hospitals are boring. If patient is asleep or carted off for a test or otherwise out if it & you're there, there is nothing for you to do. If kids in that mix, there's really nothing for them to do. If not at hospital, home care situation is still similar - kids will go stir crazy real quick - at a time you need calm. Plan for shifts and a lot more for them to do beyond tossing them an iPad....
4. Consider a garment bag with appropriate funeral clothes. Morbid, but you don't want to be making a long roundtrip home just to get clothes or running to stores & trying to find stuff for visitation & funeral service - carry it just in case & be prepared. Learned that one the hard way....
Not really something to pack, but if a situation looks grim, someone needs to be designated to police the vultures. So many long-lasting ruined family relationships from the vultures coming in and picking through sentimental items when those closest are at the hospital or out making arrangements or whatever. It is so unreal how many family members - that all your life you considered to be normal, decent human beings - feel absolutely entitled to go pick through someone's possessions while that person is literally on their deathbed.
If you don't already have a bag, the SOC 3-day pass is a very nice bag and good size for a 3-day bag for two adults. Pretty versatile, well constructed, and not insanely priced like a high end tactical pack.