Halloween II (1981)

Answer: I have read that, in early drafts of the script, the hospital was a health clinic, not a standard hospital. This would possibly explain why there are only a small number of patients, though it doesn't explain why there is a maternity ward, or why the mother brings her son there for emergency treatment.

Answer: One could argue that Haddonfield is a small town, and perhaps there just aren't that many doctors, nor that many patients in the hospital at any given time. It really just depends. Also, I've had to go to the ER a number of times in my life. Most of the time, it's busy, but there has been a few times where it has been pretty much completely dead and empty, not too dissimilar from what you see in this movie. So it could possibly just be a slow night.

TedStixon

Answer: Apparently there were quite a few patients at HMH. If you remember the scene where Karen was putting pills into individual cups just before the room buzzer goes off, in which she finds Bud under the sheet, there are many of those cups. Also we know for certain there was a patient named Ms. Carr who was supposed to receive attention at 9:30 the next morning, told to Karen by Ms. Alves, while Michael was standing in the rear of the nursery area watching them. And of course there were all the newborn babies, leading me to believe there were a few new mothers in the hospital as well.