Improving the safety of peripheral intravenous catheters

Abstract

Specialised teams and technology could bring greater benefit than routine replacement

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 studies^{4 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 , Webster and colleagues report a large randomised controlled trial of different methods of managing peripheral intravenous catheters,¹¹ following an earlier pilot study,¹² seeking scientific validation that peripheral venous catheters no longer need to be replaced at least every 72 hours. In total, 755 medical and surgical patients were randomised to have their peripheral intravenous catheter routinely replaced every three days (control group) or only when clinically indicated, for phlebitis, infiltration, or unexplained fever (clinically indicated group). The study found no significant difference between the groups in premature removal of catheters for phlebitis or infiltration (relative risk 1.15, 95% confidence interval 0.95 to 1.40). The authors estimate that peripheral infusion related costs could be reduced by about 25% if hospitals replaced catheters only when clinically indicated, rather than at 48-72 hour intervals. However, they conclude that larger trials are needed to support this policy if phlebitis is used as the primary endpoint.

Considering that nearly 200 million peripheral intravenous catheters are used each year in US hospitals alone,⁹ Webster and colleagues’ trial is important. A limitation of the trial, however, was that the nurses who provided clinical care assessed the insertion sites when the catheters were removed, rather than researchers. Moreover, the study was done in a hospital with a dedicated nurse intravenous therapy team. The incidence of all complications, especially phlebitis, is greatly reduced when highly experienced nurses insert the catheters and provide follow-up monitoring and care,⁷which may explain why the incidence of phlebitis in the trial was low.

As a consequence, it is unclear how well the results can be generalised to the majority of hospitals, which do not have intravenous teams. The study is also underpowered to reliably conclude that abandoning periodic replacement of peripheral intravenous catheters is unlikely to increase the incidence of infiltration or phlebitis. In addition, the cost analyses did not include the estimated costs of treating severe phlebitis and infiltration or the rare cases of peripheral intravenous catheter related bacteraemia (about 1-3/1000 catheters^{7 9 10}) that will certainly occur, mostly after 48 hours of catheterisation.^{4 7 10} Finally, large cohort studies show that the risk of intravenous phlebitis rises significantlyafter 48 hours not 72 hours,^{4 6 7} and a large randomised trial comparing routine peripheral intravenous catheter replacements at 48 hours with replacing catheters only when clinically indicated might well show a significant reduction in phlebitis and costs with routine replacement.

Large randomised controlled trials have shown that using specialised teams to insert and care for all peripheral intravenous catheters,⁷ or adopting simple and relatively inexpensive technological advances—such as using in-line filters to remove microparticulates within the infusate,¹³ using catheters made of polyetherurethane rather than Teflon,^{5 6} and securing catheters with a new tapeless device¹⁴—each substantially reduced the incidence of infusion phlebitis and was cost effective. Specialised teams also prevented peripheral intravenous catheter related bacteraemia.⁷ Such approaches could potentially obviate the need to replace peripheral intravenous catheters at periodic intervals.

In summary, Webster and colleagues’ trial did not satisfactorily prove that not replacing peripheral intravenous catheters at 72 hour intervals is safe and cost effective, especially in hospitals that do not have specialised intravenous teams to insert and care for catheters, and the value of periodic catheter replacement remains unresolved. Although abandoning scheduled replacements may not greatly increase the incidence of infusion phlebitis and infiltration in the average hospital that currently replaces peripheral catheters at 72 hour intervals, it would probably increase the risk of catheter related bacteraemia with Staphylococcus aureus.^{4 7 10} A large well designed randomised trial comparing replacements at 48 hour intervals with replacement only as clinically indicated would be likely to show significantly fewer local complications and, if the study was adequately powered, a reduced incidence of catheter related bacteraemia as well. But having a specialised team insert and care for catheters clearly reduces both phlebitis and bacteraemia. Moreover, adopting one of the technologies described can also reduce infusion phlebitis and be cost effective, whether or not the hospital replaces peripheral catheters at scheduled intervals.

Cite this as: BMJ 2008;337:a630