Not a surgical resident, but did get a puppy last Oct. with a rather busy schedule (that doesn't even compare to what you'll be doing, just 40 hrs a week, plus commuting to grad school twice a week). I would not recommend it with the schedule you'll be keeping if you live alone.
I love him to death, but I wound up getting a dog with some med issues. I make a bit more money than our residents here and it was expensive to care for him and I had to find someone to stay with him for several nights while I was at work because he needed meds during that time and needed to be let out every 1-2 hours for a Giardia infection that wouldn't go away. That's not exactly rare. It seems it's hard for some surgery residents on here to even ask for a sick day for themselves, let alone call and say, can I be late have to take the dog to the vet for something serious.
Med issues aside, dogs need companionship and the ideal is for them to bond with their owner not a dog walker or doggy day care. Most dogs, even older dogs you adopt are going to need at least some training that will require quite a bit of time and attention. Older dogs will also probably need more bonding with the owner because of their history. Rescue dogs typically need more consistency and structure. I worked nights 4 days a week so I wound up feeling guilty cuz he'd be cooped up for 10 hrs. I'd exercise him and train when I'd get home, then have him out with me for couple hours before I'd go to bed. Then back to the mudroom with him. You can plan on having your sleep schedule dictated not just by your residency schedule but also your dog even if he's not a puppy.
I was having a hard time socializing him to other dogs and people like he needed so we'd go to the dog park, but there were bad dogs there. So finally I wound up taking him to doggy day care the two days a week I had grad school. That seemed to work well and is still how we're doing things. From what I gather at the doggy day care place, a lot of the hospital staff brings their dogs, and they're pretty flexible so if the owner has to stay late or overnight the dog can stay overnight at daycare.
It'll be really hard for you to find a balance that's fair for the animal. There are options that might work, but honestly I'd get a cat or something that's more independent. Another option would be to volunteer at a shelter or vet clinic to get doggy time or volunteer to walk the dog that's staying with you (or other residents dogs ;-) or have him over for visits on your days off.
