Failure modes: infiltration, phlebitis and the vasovagal faint
Most at-home infusions are uneventful, but three failure modes account for nearly all the problems, and knowing them makes you a safer customer. The first is infiltration: the cannula tip slips out of the vein and fluid runs into the surrounding tissue instead. The signs are a swelling that feels cool and tight around the insertion site and a drip that slows or stalls. It is rarely dangerous with plain saline — the body reabsorbs the fluid — but the infusion must be stopped and resited. This is why the nurse should stay for the entire session and glance at the site regularly, and why any provider whose nurse starts the drip and leaves the room for long stretches is cutting the corner that matters.
Two reassurances backed by physiology: the small air bubbles you may see in the line are not the movie scenario — it takes a large volume of air to cause harm, far beyond what tubing bubbles contain. And infection risk at the insertion site is genuinely low when asepsis is followed: skin cleaned with chlorhexidine or alcohol and allowed to dry, gloves, single-use everything, and a sharps container that the nurse brings and takes away. Watch for that sharps box — its absence is a red flag you can spot from across the room.