Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for severe breathing difficulty, collapse or unresponsiveness, blue or grey coloring, or bleeding that does not stop with gentle pressure.
Contact the healthcare team promptly if the dressing becomes wet, loose, dirty, or lifted, or if the catheter appears to have moved.
Also report repeated pump alarms, trouble flushing, leaking, or blood visible in the tubing when it is not expected.
Ask for urgent assessment if your infant has swelling, increasing redness, warmth, a color change, blistering, drainage, or apparent pain around the catheter or limb.
A new fever, unusual temperature instability, marked sleepiness, or poor feeding also needs prompt medical advice.
Stop using the line and alert the team immediately if it breaks, comes out, leaks during an infusion, or if fluid will not pass easily.
Do not push it back in or force a flush.
Every sign above is quoted from the sofidex article on Midline venous catheters - infants. If you are not sure, err upward — it is always reasonable to be checked.