No. Doctors can have mostly normal 8-hour workdays, 5 times per week. Nurses administer drugs and monitor the patients. If a problem arise, they can call the doctor in charge of the patient or bring the doctor doing the night —or weekend— shift.
>> Friend's mother was recently in hospital, multiple doctors thru a single day, each one had to completely relearn what was going on.
> What's the alternative? 24 hour shifts for the doctor and the new doctor each day needs to relearn everything?
This is from your response:
> Is there really a need for 24 hour doctor visits most of the time?
The exact situation described is hospitalization. Pointing out that most treatment may not be on a 24h basis is not relevant here.
As has been pointed out in many submissions on HN about USA's medical practices, the main reason you get many visits is to inflate your bill. I think someone even wrote that he was charged $600 per 1-minute visit during his stay in the hospital.