In the following clip, the nurse asks the porter if he could do her another favour.
The porter says: "I haven't seen him so far today, though" meaning that he hasn't seen the other porter up to this point of the day.
The nurse says: "Nobody escapes in this hospital." which sarcastically means that when working at the hospital, everyone should be ready for action at any moment.
If someone is “on call” it means that they are expected to be ready and available for work.
