Preventing Catheter-Related Bloodstream Infections: Title and subTitle BreakThinking Outside the Checklist

The medical care system is at a crossroads in the control of health care–associated infections. For years, the status quo has been defined by scattered local success stories but an overall failure to protect patients from largely preventable infections. These infections have enormous human and economic costs, with an estimated 100 000 deaths and $6.5 billion in excess expenditure annually in the United States alone^{1 - 2} and estimates of 1.4 million patients affected daily worldwide.^{3 - 4} Catheter-related bloodstream infection is a leading contributor to health care–associated infection. Approximately 80 000 catheter-related bloodstream infections occur annually in US intensive care units (ICUs) and are associated with as many as 24 000 patient deaths.⁵ Each of these infections is estimated to have a mean attributable cost of $18 000 and an associated excess hospital stay of 12 days per episode.⁶

There are many reasons for this global epidemic of health care–associated infections, including payment systems that neither reward best practice nor punish poor performance. However, in many countries, the payment systems reward poor performance by providing additional reimbursement for incident infections. To counteract this, since October 2008, the Centers for Medicare & Medicaid Services will no longer reimburse hospitals for expenses associated with catheter-related bloodstream infections.⁷ Similar strategies have been proposed in some countries in Europe and elsewhere.

Additional reasons for the fragmented responses to infection include the lack of clinical trials and cost-effectiveness analyses to guide best practice at societal as well as individual hospital levels. Without direct reimbursement for specific initiatives for infection prevention, hospitals have been forced to make economic decisions about funding infection control interventions with limited data and an eye on their bottom line, the outcome of which may not be aligned with the greatest societal benefit.⁶

Into the breach of these failures have stepped governmental and other bodies that seek to mandate specific practices. For example, the Veterans Health Administration and the State of Illinois have instituted mandatory screening for methicillin-resistant Staphylococcus aureus (MRSA), and starting in January 2010 the Joint Commission's Hospital Accreditation Program National Patient Safety Goals will require the use of a catheter checklist and a standardized protocol for central venous catheter (CVC) insertion, along with other measures.⁸

Given the high incidence and mortality associated with catheter-related bloodstream infection, it is not surprising that numerous strategies including bundled interventions have been studied. Successful approaches have been as varied as 1-day educational programs⁹ and a comprehensive multistep policy with targeted education to address the proper insertion and maintenance of CVCs.¹⁰ The most frequently cited bundle of interventions includes appropriate hand hygiene, use of chlorhexidine for skin antisepsis, use of maximal sterile barrier precautions (mask, sterile gown, sterile gloves, and large sterile drapes) during catheter insertion, avoidance of the femoral vein, and prompt removal of unnecessary catheters.¹¹ Adherence to these basic infection control practices was tracked using a checklist and was associated with a 66% reduction in catheter-related bloodstream infections in a quasi-experimental study.¹¹ The success of this strategy is evidenced by its adoption by the Institute for Healthcare Improvement¹² and the Joint Commission,⁸ although this strategy has not reduced catheter-related bloodstream infections to zero, neither in the aforementioned trial nor in actual practice.

The most recent data from the Centers for Disease Control and Prevention's National Healthcare Surveillance Network showed that even though rates of catheter-related bloodstream infection decreased 54% in the medical-surgical ICUs of major teaching hospitals, the rate was still approximately 3 infections per 1000 catheter-days.¹³ Fortunately, other preventive measures exist. Numerous trials have reported the benefits of antiseptic- or antimicrobial-coated catheters.^{14 - 16} However, many of these studies were conducted in settings with high baseline rates of catheter-related bloodstream infection. Thus, even though the comprehensive bundled interventions are less than 100% effective, current guidelines recommend antiseptic- or antimicrobial-impregnated catheters only in settings where targeted rates are not met, despite the institution of bundled basic strategies for prevention of catheter-related bloodstream infections.^{17 - 18}

A major unanswered question is what to do when rates of catheter-related bloodstream infection are low after instituting best practices during line insertion and maintenance. Against this background, in this issue of JAMA Timsit et al¹⁹ report the results of a study with the potential to change the standard of care for insertion and maintenance of intravascular catheters. Using a multicenter, assessor-blind, 2 × 2 factorial, randomized controlled trial, the authors demonstrate the benefit of placing a chlorhexidine gluconate–impregnated sponge (CHGIS) at the catheter insertion site immediately after insertion, at 24 hours, and at each subsequent dressing change in adult ICU patients. In addition, the authors evaluated the noninferiority of a strategy delaying all subsequent dressing changes after the initial 24-hour change from every 3 to every 7 days. The most important finding is that the use of a dressing incorporating a CHGIS was associated with a significant decrease in major catheter-related infection, catheter-related bloodstream infection, and catheter colonization rates. The rates of catheter-related bloodstream infection decreased from 1.3 per 1000 catheter-days to 0.4 per 1000 catheter-days; catheter colonization rates were similar at the 3-day and 7-day dressing change.

Several important factors must be considered when interpreting these results. First, the 76% relative decrease in catheter-related bloodstream infection occurred in ICUs with already low rates. The rate of catheter-related bloodstream infection was 1.28 per 1000 catheter-days in the control group with dressing changes every 3 days and without use of a CHGIS dressing. None of the 7 ICUs in the study used antiseptic- or antimicrobial-coated catheters. All ICUs were reported to practice the recommended insertion and care of catheters, including maximal sterile barrier precautions, though no compliance information was presented. As the authors noted, the currently recommended 2% aqueous chlorhexidine was not available for skin antisepsis during the study. It is possible that some of the observed benefits of the CHGIS dressing would have been attenuated if 2% chlorhexidine had been used, although no trial has demonstrated that chlorhexidine is superior to the alcohol-based povidone iodine formulation used in the study. Operators inserting the catheters were encouraged to favor the subclavian site, although approximately 60% of venous catheters were inserted in the jugular and femoral veins. While pulmonary arterial, hemodialysis, and peripherally inserted CVCs were excluded, femoral and radial arterial catheters combined accounted for 46% of the inserted catheters in the study.

At first glance, the inclusion of arterial catheters might appear to limit the generalizability of the findings in regard to CVCs, because arterial catheters have a lower perceived risk of associated bloodstream infection. A study by Koh et al²⁰ found that arterial catheters were associated with a lower rate of bloodstream infection than CVCs (0.92 per 1000 catheter-days vs 2.23 per 1000 catheter-days, respectively), despite similar catheter colonization rates. In a systematic review of articles using strict criteria for outcome determination, Maki et al¹⁴ found that arterial catheters had approximately half the incidence density of bloodstream infection compared with nontunneled CVCs (1.4 per 1000 catheter-days vs 2.9 per 1000 catheter-days, respectively). Thus, while arterial catheters are associated with lower infection rates, they remain a source of substantial morbidity, with some reports estimating as many as 48 000 arterial catheter–related bloodstream infections in the United States each year.²¹ Therefore, even though arterial catheters are not included in recently published guidelines or prevention bundles, these devices would still be an important target for interventions, including insertion bundles, directed at reducing bloodstream infection associated with their use.²¹ Although Timsit et al¹⁹ do not report a breakdown of bloodstream infections by catheter type, a future subanalysis of the study data would help to clarify this issue, and additional studies should specifically evaluate interventions to reduce bloodstream infections related to arterial catheters.

The other important finding of the study by Timsit et al¹⁹ was that dressing changes after the initial change at 24 hours could be safely delayed to 7 days. Importantly, both the 3-day and 7-day intervention groups required immediate dressing changes for any leakage or soiled dressings. This suggests that clinicians must be constantly vigilant to the appearance of the dressing to achieve these low rates. A sobering fact is that very few patients had their second dressing change delayed to day 8, given that the mean number of dressing changes was similar in the 3-day and 7-day groups (4.5 vs 3.8, respectively). On the plus side, this is partially explained by the relatively short duration of catheter use (median, 6 days) in all study intervention groups.

On the negative side, exposure to chlorhexidine was associated with 8 episodes of severe contact dermatitis (5.3 per 1000 catheter-days), and its use was discontinued in these patients. While the authors provide a number needed to treat of 117 to prevent a major catheter-related infection and suggest that use of CHGIS dressings may be cost-saving from a hospital perspective, a future cost-effectiveness analysis would need to include adverse effects and other outcomes.

Achieving the lowest possible rates of health care–associated infection is the ultimate goal, whether through mandate or individual hospital initiative. Even though the rates of catheter-related bloodstream infections have clearly declined during the past decade, efforts beyond the checklist are needed. Current guidelines suggest that the low rates achievable through optimized insertion practices and adherence to checklists might be sufficient. The study by Timsit et al¹⁹ has the potential to change the current clinical approach, given that rates of catheter-related bloodstream infection were driven even lower through the relatively simple use of a CHGIS dressing. Future advances in infection prevention will require similar investments in government-sponsored, high-quality randomized controlled trials.