I have to agree with RAMd®d. Since my mother's been closely involved with various local wildlife rescue organizations (pretty much still on an outside basis but with knowledge of what really goes on), I've learned a lot about what happens to cat caught animals.
Even if an animal's injuries seem non-existent to very slight, they will still often die. If not from shock, from the injuries themselves or from infections which take hold soon after. Baby bunnies seem to have it the worst. Even if seemingly uninjured, they often die from shock. Birds too.
And I'm all too familiar with the aftermath of a snake attacked by a cat. My mother had noticed a garter in her back yard several years ago. She thought nothing of the fact he was just sitting there. It wasn't until she came back the next day & found him in the exact same position that it hit her.
When she picked him up, she couldn't even see any visible injuries. It wasn't until she took him to a rehabber friend that she found out what had happened. The snake had various puncture wounds. Its back is undoubtedly broken in numerous places. If it hadn't been for the rehabber's knowledge & access to antibiotics & my mother's amazing devotion, the snake wouldn't be alive today.
Numerous infections set in at the site of the tiny cat punctures. This caused & a broken back caused numerous kinks. The snake can only move the upper 1/3 of its body. Some might argue that the snake would be better off dead. We see it differently. He's an ambassador & he goes to nearly all of our snake programs. He doesn't appear to be in any pain (& once you've seen a snake in pain, you learn to recognize the signs of suffering). He lives with several friends which seem to have accepted him. My mother checks on him numerous times every day. She makes sure he drinks (he can't quite reach it to the water bowl) & he has a good appetite now.
Sorry to get off on a tangent. Please keep us updated on how the chipmunk does. If I'd been here earlier in the day, I would have suggested getting him to a wildlife rehabber or a vet asap. I hope the little guy does ok!