Device-Related Infections

Device-related infections have been a big problem for a long time. Advances have been made and clinicians have worked tirelessly to remedy the problem, but it simply hasnt been enough. These infections are still occurring and some of the repercussions are staggering.

The three most common device-related infections are central line-associated bloodstream infection, ventilator-associated pneumonia (VAP), and foley catheter-associated urinary tract infection (UTI). Recent studies have also named several medical implants¹ to the list. This is because the problem-causing infectious agents are difficult to eradicate because the bacteria that cause these infections live in well-developed biofilms. Total parenteral nutrition and femoral catheter devices² also have been mentioned and both have been tied to catheterrelated vancomycin-resistant E. faecium bacteremia to boot. Even surgical sutures now play a role in the etiology of infections because they too can harbor both gram negative and gram positive bacteria.³ 

According to data from the Centers for Disease Control and Prevention (CDC), the majority of serious catheter-related infections are associated with central venous catheters (CVCs). CVCs have long been associated with bloodstream infections (BSIs). In fact, approximately 90 percent of all catheter-related bloodstream infections (BSIs) occur with CVCs.

CDC says that these infections occur most commonly in those that are placed in patients residing in the intensive care units (ICUs). This is due mainly to the higher incidence and need of central venous access, and the extended periods of time in the hospital that may be required for this patient group. Patients often are afflicted with hospital-acquired organisms because the catheter is manipulated multiple times per day for the administration of fluids, drugs, and blood products. Moreover, some catheters are inserted in emergent situations, during which optimal attention to aseptic technique may not have occurred.

The CDCs published data on the incidence of these infections reflects that in the United States, 15 million CVC days occur in ICUs each year. At the average rate of CVC-associated BSIs of 5.3 per 1,000 catheter days in the ICU, approximately 80,000 CVC-associated BSIs occur in ICUs each year. Moreover the cost per infection is an estimated $34,508 to $56,000, and the annual cost of caring for patients with CVC-associated BSIs ranges from $296 million to $2.3 billion in the U.S. alone.

Whats worse is mortality attributable to these infections, which rest at an estimated 12 to 25 percent for each infection. Studies of catheterrelated bloodstream infections that control for the underlying severity of illness suggest that attributable mortality for these infections is somewhere between 4 and 20 percent, and it is estimated that between 500 and 4,000 U.S. patients die annually due to these BSIs, according to CDC statistics.

Lynn Hadaway, MEd, RNC, CRNI, president of Lynn Hadaway Associates Inc., long-time member of the Infusion Nurses Association (INA), and executive director of the National Alliance for the Primary Prevention of Sharps Injuries (NAPPSI), says the CDC data is the best data currently available, however, she points out that it is just related to critical care patients in an ICU environment. She adds that CDCs document states that 80,000 BSIs occur annually in US ICUs, but she says, If you look at the entire hospital, that number jumps to about 250,000, and when you look at the entire healthcare system, the number of catheter-related BSI is estimated to be as high as 500,000.

Hadaway explains that the biggest problems that stem from CVCs are BSIs and thrombosis. Infiltrations, extravasations, and nerve damage can occur from all kinds of catheters as well.

The percutaneously-placed CVCs U.S. the ones that go in directly through the jugular vein U.S. carry the greatest risk of infection, according to Hadaway. The risk comes from the skin because the skin in that area is oily and the density of the organisms of the skin in that area is greater. She also explains that there is increasing concern about the infection risk with peripherally inserted central catheters (PICCs) now too.

Traditionally, we thought PICCs had a very low infection rate, but that data has primarily come from home care where the risk is going to be lower than a hospital situation. There is one article that shows that in hospital outpatients, the infection rate with PICCs is about equal to other CVCs, she declares.

Hadaway further explains that the arm, where the PICC is inserted, holds a lower risk than the other more organism-laden areas of the body. She says this is due to the dry skin on the extremities having a different profile of bacteria, and a different density of organisms compared to the neck and the chest where the other types of CVCs commonly are inserted.

But thats still only looking at roughly half the picture, she notes, because the other half of the risk comes from hub manipulation and catheters that have been in for long times (e.g. several weeks, months) have a greater risk of being infected from hub manipulation compared to skin. So it is what the caregiver is doing to the hub of the catheter that increases the risk of infection. You could have a very high infection rate with tunnel catheters or PICCs or implanted ports, due to hubs, not skin.

She offers that the remedy for this is a standardized approach that is research-based. For example, she points out what the 100K Lives Campaign, launched by the Institute for Healthcare Improvement, implemented in its program relating to lowering device-related infections.

They are taking the most effective approach, Hadaway says, because they have bundled a set of practices together. They really have good data that supports the number of lives they have saved, she adds, and, that bundling approach, when you do all five steps, has been documented to decrease infection rates.

The Central Line Bundle used in the 100K Lives Campaign is a group of evidence-based interventions for patients with intravascular central catheters that, when implemented together, result in better outcomes than when implemented individually, notes Hadaway.

The key components of the Central Line Bundle are: 

• Hand hygiene 

• Maximal barrier precautions upon insertion 

• Chlorhexidine skin antisepsis 

• Optimal catheter site selection, with subclavian vein as the preferred site for non-tunneled catheters 

• Daily review of line necessity with prompt removal of unnecessary lines 

Hadaway asserts that to be effective, all of these things must be adhered to.

The one thing that is not addressed in their set of recommendations is the nursing care, she adds. When you think about it, putting a catheter in is only going to be about 30 minutes to an hour in the procedure. Then, it goes over to the nursing staff to handle the catheter. Whos doing what to the catheter? To the hub? To the dressings? Everything that is done to that catheter can be done by a whole host of nurses some with a lot of knowledge and skills and some without, so the patient is really at the mercy of the knowledge and skill level of that person taking care of that catheter.

Rabih Darouiche, MD, professor and director at the Center for Prostheses Infection at the Baylor College of Medicine, has been heavily involved in device-related infection research for many years. He has published countless studies on the topic and over the years has never wavered in his resolve to help find the answers to reduce these infection rates.

During my residency and training, I realized that the best research I can do is to answer clinically-complex questions and one of the most common and serious infectious complications I had to deal with, was the difficulty in curing infections we faced with multiple medical devices without having to remove the device, he explains. This is what prompted me to pursue the study of device-related infections particularly prevention of device-related infections.

Some of the research he has been involved with has found that intravascular catheters and urinary catheters are the two most commonly inserted medical devices in the US, and are the two most common causes of nosocomially-acquired BSIs.⁴ He has also found that the cornerstone to any preventive strategy for a catheter-related infection is strict attention to infection control practices. Make sure that you adhere as much as possible to basic infection control measures, Darouiche offers. We also have to utilize clinically effective technological advances, he offers.

One of those advances has been the use of clinically effective antimicrobial coated devices. Interestingly, Darouiches current research encircles antimicrobial coating of a number of surgical implants, and exploring the benefit of combining an antimicrobial agent with an anti-biofilm agent for management of device-related infections.

Guidelines set by the National Institutes of Health (NIH) recommend the use of an antimicrobial- or antiseptic-impregnated CVC in adults whose catheter is expected to remain in place for more than five days.⁵ However, Darouiche also points out that the efficacy of such advances will depend upon an array of circumstances. Nothing is foolproof.

For example, if you compare those technologic advances in the context of central venous catheters, they really do not apply that well to bladder catheters, he explains. That is because the bacterial involvement is so different between vascular and bladder catheters. With vascular catheters, you have to prevent infection by bacteria that usually, not always, originate from the patients skin at the insertion site and are present in relatively low concentrations like maybe in a 1,000 or 10,000 colony-forming unit on the skin around the catheter insertion site.

Whereas in the bladder, the catheter is exposed to hundreds of millions of bacterial colonies that exist in the urine. This implies that an antimicrobial coating that is clinically protective when applied to a CVC would not necessarily be protective when incorporated onto bladder catheters. It is likely to be overwhelmed by the extremely high bacterial concentration that exists in the bladder.

One underlying cause of catheter-associated UTI has been found to be caused by a biofilm formation by uropathogens on the urinary catheter,⁶ and researchers found a marked difference in lowered infection rates by implementing simple infection control measures such as the prompt removal of unnecessary catheters.

Darouiche adds there is a good probability that the clinical success seen with antimicrobial-coated vascular catheters can extend to antimicrobial- coated surgical implants. He explains that this is because surgical implants share similar microbiology with vascular catheters in terms of being effected mostly by staphylococcal organisms as well as relatively low bacterial concentrations in the surrounding environment.

Another thought related to device-related infections, according to Darouiche, is that the whole picture needs to be carefully considered and all risks need to be balanced and well thought out. If the rate of device-related infection is not that high, but is known to result in serious complications, then you have to consider technological advances that have been proven to be clinically effective, he notes. Either when applied to that particular device or when applied to other devices that share similar microbiology and pathogenesis of infection.

Either the rate of device-related infection is still relatively, unacceptably high or if you even with a low rate of infection deal with a serious device-related infection; lets say an aortic vascular graft infection where the rate of infection is just 2 percent; that is lower than the rate of infection for a bladder catheter which can be as high as 20 to 30 percent. But the 2 percent incidence rate of an aortic vascular graft infection is much more serious than the 30 percent incidence rate of catheter-related UTI, because the mortality from infection of the aortic vascular graft is 50 percent. So one of two people with infected aortic graft will die. In that regard, even a 1 percent incidence rate of infection must be comprehensively addressed in terms of combining infection control measures and technological advances, he warns.

The highest occurrence of device-related infection is catheter-related UTI (at 30 percent), according to Darouiche. Almost 30 million bladder catheters are inserted each year, he says. Then you have the second most commonly utilized device and that is the central venous catheter. You have about 6 million of these with a rate of bloodstream infection of probably 4 to 5 percent. But the complications are very serious. There has been a lot of attention devoted to these two types of catheters and yet we have endotracheal tubes which can result in ventilator-associated pneumonia in at least 10 percent of the patients; the mortality is 30 percent, and yet so far we still do not have clinically protective approaches for the prevention of VAP. And, he adds, Any case of VAP is very serious.

VAP is an airways infection that develops after a patient has been intubated. It is reportedly the leading cause of death among nosocomial infections. VAP has a high associated mortality; hospital mortality of ventilated patients who develop VAP is 46 percent compared to 32 percent for ventilated patients who do not develop VAP.

Reducing mortality due to VAP requires an organized process that guarantees early recognition of pneumonia and consistent application of the best evidence-based practices.

The Ventilator Bundle offered by the 100,000 Lives Campaign is a series of interventions related to ventilator care that have been shown, when implemented together, to achieve significantly better outcomes than when implemented individually.

The key components of the Ventilator Bundle are:

• Elevation of the head of the bed 

• Daily sedation vacations and assessment of readiness to extubate 

• Peptic ulcer disease prophylaxis 

• Deep venous thrombosis prophylaxis 

In my opinion, regarding VAP, I think that is the area of device-related infections that unfortunately has received the least amount of attention, but which continues to contribute to major morbidity and mortality, asserts Darouiche. For example, the mortality of VAP can be as high as 30 percent. Depending upon the population, more than 10 percent of patients on a ventilator may develop an episode of VAP. In my opinion, that is a major type of device-related infections -- for two reasons. One, the rate of infection is high, and second, the infection is very serious in terms of morbidity and mortality, as well as in terms of economic cost. Since a single day of ICU care costs thousands of dollars, prolonged hospitalization explains why the management of VAP is so expensive.

VAP prolongs time spent on the ventilator, length of ICU stay, and length of hospital stay after discharge from the ICU. According to the Institute for Healthcare Improvement Web site, VAP adds an estimated cost of $40,000 to a typical hospital admission.

I have seen some very bad outcomes that can be prevented, Hadaway asserts. This is an area where nurses should be taking a leadership role. There is no standardized way for nurses to be trained on this and theres no standardized way for physicians to be educated and trained on putting in catheters and all the latest information about reducing the risks; so it leaves the door wide open for a lot of bad outcomes.

I think this is an area where nurses can and should be stepping up to the plate to take a leadership role because we take a holistic approach to patient care. Were looking at the whole person and we see how that catheter is going to impact their lives. 

References

1. Costerton JW, Montanaro L, Arciola CR. Biofilm in implant infections: its production and regulation. Int J Artif Organs. 2005 Nov;28(11):1062-8.

2. Raad II, et. al. Catheter-related vancomycin-resistant Enterococcus faecium bacteremia: clinical and molecular epidemiology. Infect Control Hosp Epidemiol. 2005 Jul;26(7):658-61.

3. Edmiston CE. Bacterial adherence to surgical sutures: can antibacterial-coated sutures reduce the risk of microbial contamination? J Am Coll Surg. 2006 Oct;203(4):481-9. Epub 2006 Aug 22.

4. Trautner BW, Darouiche RO. Catheterassociated infections: pathogenesis affects prevention. Arch Intern Med. 2004 Apr 26;164(8):842-50.

5. OGrady NP. et. al. Guidelines for the prevention of intravascular catheter-related infections. [published erratum appears in MMWR Weekly 2002 Aug 16;51(32):71]. MMWR Recomm Rep 2002 Aug 9;51(RR-10):1-29. [293 references] PubMed.

6. Trautner BW, Hull RA, Darouiche RO. Prevention of catheter-associated urinary tract infection. Curr Opin Infect Dis. 2005 Feb;18(1):37-41.

7. IHI. Implement the Ventilator Bundle. 100K Lives Campaign.
www.ihi.org/IHI/Topics/CriticalCare/IntensiveCare/Changes/ImplementtheVentilatorBundle.htm.  

CASE STUDY

Regions Hospital, St. Paul, Minnesota

Regions Hospital, a 427-bed, fullservice, private hospital, initiated both the Ventilator Bundle and Central Line Bundle elements into its critical care units, and data show that the use of the bundles has been associated with reductions in infections -- especially a decrease in VAP rates.

In 1997, VAP rates in Regions surgical ICU were 29 per 1,000 ventilator days. In 2004, the rate dropped to just below 18 per 1,000 ventilator days. Similar declines have been seen in the medical ICU and in the burn center. Catheter-related BSIs have also dropped.

Regions staff standardized line insertion practices across departments, and used maximum barriers when inserting central lines (i.e. sterile gown, gloves, mask and hat, and a large drape on the patient), and these efforts have proven effective in decreasing the likelihood of developing a BSI.

One of the staffs more effective actions involves that of flagging lines that were inserted in less than ideal situations and ensuring they are changed out in a timely manner before infection sets in. Regions Hospital is a Level I trauma center so emergency interventions to save lives can sometime necessitate inserting a central line under less-than- ideal conditions. Lines inserted in this fashion must be removed within 24 hours to reduce the likelihood of acquiring an infection.

The need for a clearer way to communicate between departments which lines need to be removed within 24 hours of insertion was evident, so staff began placing a red sticker on the line to indicate its need to be changed.

In contrast, a green sticker is placed on lines that are administered in the emergency department using maximum sterile barriers.

Source: Institute for Healthcare Improvement. www.ihi.org