IV Catheters

June 1, 2000

IV Catheters

By Lisa S. Higa

Today's
hospitals rely on IV catheters as essential tools to deliver IV medications, blood
products, and nutritional fluids to patients. Approximately, 90% of all patients entering
the hospital environment for care have some form of intravenous therapy during their
hospital stay. Administering vital medications to these patients through the use of IV
catheters can be complicated by related serious infections. Complications of peripheral IV
site therapy are typically grouped into localized, mechanical, or systemic categories.
When peripheral IV sites fail, patients typically experience localized phlebitis.
Replacing peripheral IV catheters can be challenging if the patient has poor peripheral
venous access resulting in medication and intravenous fluid schedules disrupted.
Complications may progress forming a thrombus, causing thrombophlebitis, or
catheter-associated infections or bactermias. Based upon current knowledge, it is
impossible to predict which patients will develop peripheral cannula associated
complications causing repetitive peripheral IV failure, but recent data evaluating the
performance of individual peripheral IV sites suggests a repetitive pattern to site
failure. When repetitive peripheral IV access fails and intravenous medication doses and
fluids are missed, healthcare providers consider placing the more expensive devices such
as peripherally inserted central catheters (PICC) or implantable ports.

The duration of the intravenous site may range from minutes to months and should be the
first criteria to consider when selecting an IV catheter. The primary goal of the
healthcare provider is to select the appropriate IV device and initiate therapy with the
shortest, smallest gauged catheter that is therapeutically and economically necessary to
sustain the treatment effect safely. Reported incidences of phlebitis ranged from 10% to
90% of peripheral IVs with symptoms occurring within eight hours of placement. In response
to early studies, intravenous drug manufacturers and pharmacists recommended adjusting
medication dilution volumes and increasing infusion times for piggyback medications. As a
result, a few recent studies cite decreases in the incidences of phlebitis as little as 2%
to 22%. The least frequent episodes of phlebitis occur at PICC and CVC cannula sites.

Patients with short term peripheral IV or intravenous catheters may develop phlebitis
as a complication, but rarely are these types of catheters associated with major
blood-stream infections. When patients move their extremities, the mechanical movement
jostles peripheral intravenous catheters as well. The insertion site may eventually show
irritation leading to phlebitis with short term peripheral intravenous catheter usage-skin
preparation, length of use, activity of catheter site, skin contamination, catheter
material, and chemicals/medications administered. When the vein/artery is irritated, the
risk of catheter-related infection increases as well. Peripheral arterial catheters often
monitor hemodynamic status of acutely ill patients or are used to administer chemotherapy.
Incidence of catheter-related infections, especially serious bloodstream infections is
reported to be even lower than those associated with short term peripheral venous
catheters. Though no study has identified why peripheral arterial catheters have lower
rates of infection, two possible explanations are that vascular pressures are higher and
that, located on the extremities, these sites are less affected by a patient's small motor
movements. As with most catheter sites, inflammation at the insertion site or duration of
over four days will make the patient more susceptible to catheter-related infections.
Central venous catheters are associated with 90% of all catheter-related bloodstream
infections. These multi-luminal types of catheters are the most commonly used by
physicians for administering fluids and monitoring pressure of critically ill patients.
Yet, because of the multiple ports, manipulation at the catheter site lead to trauma.
Eventually, this and other factors, such as seriousness of the patient's condition, the
site, lengthy duration of catherterization, and other factors contribute to a high risk of
infection. The higher the number of lumens, the greater the risk of contamination.

Central arterial catheters take introducers and remain in place for approximately three
days. Most use heparin locks, which reduce thrombosis and cut down on microbial adherence
to the catheter. Longer insertion times and catheter insertion without using the highest
level of protective barriers (gloves, drapes, masks, and gowns), location of the catheter,
and condition of the patient all contribute to higher levels of infection in this type of
catheter. Peripherally inserted central venous catheters (PICCs) insert into the superior
vena cava by using cephalic or basilic veins. Because of their peripheral insertion, PICCS
are associated with fewer complications due to mechanical manipulation (thrombis,
phlebitis) and lower rates of infection than other central venous catheters. Longer
insertion durations (10 days to 12 months) are possible, with no established or
predetermined cut offs backed by research.

The skin offers a high level of protection from infection; therefore, tunneled central
venous catheters and totally implanted intravascular devices reportedly have low rates of
catheter-related bloodstream infections from 10 to 20%. These devices require surgical
insertion and are generally used for patients requiring long-term vascular access
(chemotherapy, home infusion, and hemodialysis. Midline catheters do not enter central
veins, but instead are peripherally inserted with the tip terminating in the proximal
portion of the extremity. Midline catheters are gaining in popularity because of their
lower incidence of infection as compared to central catheters. They are soft, composed of
silicone or polyurethane. Duration ranges around two to four weeks for this type of
catheter.

Prevention Strategies

Each manufacturer has a different approach to improving catheter use-latex-free,
needle-free, embedded antiseptic, safety valved, sheated, and prepackaged prep. Expert
techniques of approaching a patient's IV needs have changed over time as well. "Using
today's nursing techniques," says Lynne Moeser, consultant, IV Technologies, "we
assess the patient's venous status, consider the patient's past histories, project the
length of therapy and medications to be infused first. Then we identify venous access
devices available, consider the costs associated with each, inform, and discuss options
with the patient--then make the appropriate device selection.

"My hope is that IV clinicians and infection control clinicians can work together
more closely in the future. Early assessment of a patient's IV needs is imperative. There
would be distinct patient benefits and healthcare dollars saved if more attention were
given to correlation of the proper IV device with the therapy ordered, the patient history
and diagnosis, and vascular condition at the time of hospital admission," she
concludes.

Innovative practices require new devices, and practices improve constantly. Because new
devices enter IV therapy constantly, hospitals must train healthcare workers on the
indications for the methods of inserting IV catheters. Education and training are vital in
the fight to reduce infections and complications associated with vascular access devices.

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