Current guidelines from the United Kingdom1 and Australia2 recommend routine replacement of peripheral intravenous catheters every 48-72 hours to prevent painful infusion phlebitis and rare but life threatening peripheral catheter related bacteraemia. In the United States, Centers for Disease Control and Prevention guidelines recommend replacement every 72-96 hours.3 However, numerous large prospective cohort studies4 5 6 7 8 provide convincing evidence that the risk of bacteraemia associated with the small Teflon or polyetherurethane catheters now widely used in hospitals is only about 0.1-0.3 per 100 catheters.9 10 Because many hospitals do not have a team of nurses responsible for the insertion and care of peripheral intravenous catheters, and the average duration of catheterisation rarely exceeds three to four days, many hospitals no longer routinely replace catheters at defined intervals.

In the linked study (doi: 10.1136/bmj.a630), Webster and colleagues report a large randomised controlled trial of different methods of managing peripheral intravenous catheters,11 following …