Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Active bleeding that does not stop with firm pressure, rapid swelling around the site, or a disconnected line requires immediate help.
Use the bedside call system rather than trying to reconnect or adjust the equipment yourself.
Call emergency services for severe bleeding or if your infant becomes unresponsive or has serious breathing difficulty.
While your infant is in hospital, tell the nurse promptly if you notice new redness, swelling, leaking, bleeding, a loose dressing, or signs that the line has been pulled.
Ask for an urgent assessment if the hand or foot beyond the line becomes pale, blue, unusually red, cold, swollen, or more painful, or if the fingers or toes move less than before.
These changes can suggest reduced circulation or pressure on the limb.
Seek urgent advice for continued bleeding, spreading redness, pus, fever, or a cool or discoloured limb.
After line removal, routine questions about mild bruising or the dressing can be raised with the healthcare team.
Every sign above is quoted from the sofidex article on Peripheral arterial line - infants. If you are not sure, err upward — it is always reasonable to be checked.