Thank you all so much for your kind words and prayers yesterday.
So far, not much has changed. They did a CAT scan yesterday and said it didn't appear as though he'd had a stroke, which is good news. However, he still has not been able to wake up, and his pupils are not responding to light. They're supposed to run an EEG today to monitor his brain activity. Hopefully we'll hear something soon.
Edited to add: They neurologist is doing the EEG this morning, and is also doing a lumbar puncture to check for meningitis. We're in day six - still nonresponsive, although the doctor said there has been a slight improvement in his vitals. Doc said it could be days before there are any more improvements - weeks before he's able to leave.