Please can you give a brief introduction to intravenous catheters?
Peripheral intravenous catheters (“IV drips”) are small plastic tubes inserted into veins, most frequently in the hand or arm. They are the most commonly used medical device and their insertion is the most common invasive procedure performed in hospitals internationally: an estimated 150 million used in the USA each year and 14 million in Australia.
What are intravenous catheters used for?
Almost all hospital patients need one or more intravenous catheters to provide life-saving medical treatment. They are used to administer fluid, nutrients, medications, blood products, or withdraw blood for analysis during periods of illness.
Intravenous catheters are not without complications and frequently fail before the end of treatment because of inflammation of the vein (phlebitis). Phlebitis necessitates catheter removal and replacement. Peripheral intravenous catheter-related blood stream infection is a less frequent but serious complication, occurring in about 1 in 6000 intravenous catheters.
What is the currently accepted practice on how frequently intravenous catheters should be replaced?
Intravenous catheters are often needed for a week or more, but have been recommended for regular removal and replacement with a new catheter in an attempt to decrease both phlebitis and infection.
Routine intravenous catheter replacement no more frequently than every 72–96 hours is currently recommended for adults by the US Centers for Disease Control and Prevention (CDC), although some other countries such as Australia recommend replacement at 48-72 hours.
However, intravenous catheters are already frequently left in place beyond these recommended timeframes, typically as the result of a complex clinical judgment and appropriate reasons (eg. treatment soon to be completed, poor veins, or no available staff to cannulate).
How did your research into intravenous catheter replacement originate?
We know that the typical patient is becoming older, more obese and more difficult to cannulate. We also frequently hear grumblings from the nursing and junior medical staff who find it frustrating to remove catheters that are still working when it is so difficult to find a new vein, or indeed the time or staff with the skills to insert an IV. We hear some dreadful stories such as elderly patients with dementia having to be physically restrained in order to insert a catheter every 72 hours, or patients enduring repeated needlesticks and extensive bruising from staff trying to find a vein.
When we looked at the research, there had never been a truly large enough clinical trial to look at this practice in detail, and in addition much of the original descriptive research which suggested routine removal of catheters was necessary, was undertaken some time ago. One of the most frequently cited studies in guidelines even involved patients with indwelling steel needles which are rarely used today. Modern intravenous catheters are made of low-irritant plastics and easier on patients’ veins.
What did your research involve?
We undertook a large randomised controlled trial in three adult hospitals in Queensland, Australia. Participants were randomly assigned to receive either clinically indicated intravenous catheter replacement, or third daily routine replacement. We enrolled over 3000 patients from a range of clinical areas and monitored almost 6000 IV catheters. Research nurses visited the patients every day to assess for phlebitis, infection and other complications, but all insertions and care were undertaken as normal by clinical staff.
It was a large and expensive study, funded by the Australian National Health and Medical Research Council who realised although there were smaller studies supporting clinically indicated replacement, that we really needed this large definitive study to finally answer the question of whether we should move in this direction.
What did your research find?
Phlebitis occurred in 7% patients in both the clinically indicated and routine replacement groups. That was consistent with our hypothesis, that routine replacement was not actually necessary. Only one patient had a catheter-related bloodstream infection and this patient was in the routine replacement group, so that showed us that clinically indicated replacement is a safe approach.
No patient had a venous (local) infection and groups had equivalent rates for all-cause bloodstream infections, and catheter colonisation. Rates of infiltration, occlusion, accidental removal, total infusion failure, and in-hospital mortality were all equivalent between groups. We just couldn’t find any evidence that routine replacement had any benefit to patients.
What impact do you think your research will have?
The research should reassure clinicians of what many already suspected - that peripheral intravenous catheters can be removed as clinically indicated. If they ignore the findings and continue routine replacement policies, our data shows that it will just involve extra unnecessary invasive procedures – that means more pain for patients, wasted staff time, and higher equipment costs.
Internationally, there are numerous official guidelines for the care of intravenous catheters, and at the moment most of them are advocating routine replacement. So these will need to be updated with the results of this definitive study. We have already seen one of the more influential organisations, the Infusion Nurses Society in the US change to recommend clinically indicated removal, and others will follow.
What would be the benefits of not replacing intravenous catheters as frequently?
Routine replacement requires additional painful needlesticks, and that is definitely not a good outcome for patients. It also increases workloads for busy nurses and doctors, and is a substantial contributor to health-care costs.
Because globally a high number of patients need intravenous catheters, clinically indicated replacement would have worldwide effects on health-care costs. Of the 200 million catheters estimated to be inserted each year in the USA alone, if even 15% are needed for more than three days, then a change to clinically required replacement would prevent up to six million unnecessary intravenous catheter insertions, would save about two million hours of staff time, and up to US$60 million in health costs each year for that country alone. These savings could then be redirected to other health interventions with better evidence of effectiveness than routine replacement.
Do you have any plans for further research into this area?
It’s now clear that routine replacement is ineffective in preventing phlebitis and bloodstream infection, but there are still huge problems with catheter failure. Not just in our study but in many published works, the incidence of infiltration, occlusion and accidental removal is disturbingly high. Up to 90% of catheters fail before therapy is complete, so that is something we want to tackle.
The Australian government has just funded us for the next 4 years to undertake a similarly large randomised controlled trial to look at a range of dressing and securement techniques for peripheral intravenous catheters, including the quite radical use of skin glue for securement and to prevent bacterial migration into the blood.
Would you like to make any further comments?
Peripheral venous catheters are the workhorse of vascular access devices yet they receive a lot less focus than central venous catheters. There is a dearth of research evidence to underpin their use. I suspect this is because they don’t ‘belong’ to any one medical specialty.
In contrast to the limited evidence base, there are numerous clinical practice guidelines (CPGs) on catheter care. Official CPGs tend to be written from an infection control point of view which focuses merely on avoiding infections, which are rare although important, rather than avoiding infiltration and so on which are the more common problems.
In addition to these, different hospitals tend to write their own guidelines, often without the skills or resources necessary to do so. It’s such a huge effort and a specialized skill to develop guidelines, so even the good ones are updated only frequently and quickly become out of date.
I hope that the solution to this is the various vascular access societies that have been formed in different countries, usually by advanced practice vascular access nurses as well as radiologists and anaesthetists who have an interest in the area. These societies are growing in momentum and we have also seen two world congresses on vascular access which would be the perfect platform for professional societies to come together and take on the task of maintaining international guidelines that are evidence based but able to be rapidly updated as new studies come to light.
Where can readers find more information?
About Claire Rickard
Professor Claire Rickard is a Registered Nurse who specialised in acute and critical hospital care, before moving into research and completing a PhD in vascular access management.
She now leads Griffith Health Institute’s Intravascular Device Research Group (IVDRG) under the Health Practice Innovation program. The IVDRG includes nursing and medical clinicians, microbiologists, statisticians, economists, chemists, engineers. The group predominantly undertakes large randomised controlled trials in conjunction with major hospitals in South-East Queensland, Sydney and Perth. There is also a laboratory based program, and a team undertaking systematic reviews through the Cochrane Collaboration.
Rickard’s team is largely funded by the Australian National Health and Medical Research Council for research projects as well as to establish the first ever National Centre of Research Excellence in Nursing Interventions for Hospitalised Patients.