Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency medical help for trouble breathing, chest pain, coughing up blood, fainting, sudden major arm swelling, or a hand that becomes cold, pale, blue, or severely weak.
Contact the surgical team promptly if you develop increasing redness, warmth, swelling, or drainage around a wound; a fever; pain that is getting worse rather than settling; repeated vomiting; or numbness that lasts longer than the team said to expect.
These can usually be handled during routine office hours.
The article also says
Use the contact number provided by the treating facility if you have concerns about pain control, wound care, your sling, exercises, or medicines.
Every sign above is quoted from the sofidex article on Shoulder arthroscopy. If you are not sure, err upward — it is always reasonable to be checked.