Time for a bit of lightheartedness as things are going a bit pear shaped at the moment.
Here's a few starters:
Anesthetist: Sir, have you had an ECG? Patient: Yes, I think it was OK as it wasn't flat!
Nurse with CD drug: Name and date of birth?
Patient: I will just check my wrist band!
Nurse: Are you drinking enough?
Patient: I am afraid not! Where's the bar?