Central line–associated bloodstream infection (CLABSI) and catheter-associated urinary tract infection (CAUTI) are morbid and expensive healthcare-associated infections (HAIs).1-8 While these HAIs are prevalent in intensive care units (ICUs) and general wards, most of the research, prevention efforts, and financial penalties have been focused in the ICU.9,10 For hospitalists, who are taking a larger role in caring for the critically ill,11,12 it is optimal to understand best preventive practices.
There has been a national puTash to standardize procedures and products to prevent CLABSI and CAUTI.2,13-16 CLABSI has transitioned from a common ICU complication to a “never event.” Success has been reflected in the prevention of 25,000 CLABSIs over the last decade, translating to a 58% reduction in infections, with 6000 deaths prevented and $414 million saved.2 CLABSI prevention principles have been applied to CAUTI prevention (ie, aseptic insertion, maintenance care, prompting removal) but with slower adoption17 and fewer dramatic CAUTI reductions,18 due in part to weaker recognition19 of CAUTI as a serious clinical event, despite its morbidity20 and cost.21
Despite recent improvements in preventing HAIs, there is a marked variability in how hospitals perform in preventing these infections.22 To inform infection prevention strategies for a large-scale implementation project funded by the Agency for Healthcare Research and Quality and focused on ICUs with persistently elevated CLABSI and/or CAUTI rates,23 we performed a systematic search of interventions to prevent CLABSI and CAUTI in the ICU setting. This evidence was synthesized to help units select and prioritize interventions to prevent these HAIs.
Literature Search Strategy
We performed a systematic search to identify CLABSI and CAUTI prevention studies and synthesized findings using a narrative review process. Using criteria developed and refined from seminal articles on the topic,10,14,24-34 we searched the PubMed and Cochrane databases from their inception to October of 2015 using Medical Subject Headings (MeSHs) for “central venous catheters,” “CLABSI,” “central line associated bloodstream infection,” “catheter related bloodstream infection,” “intravascular devices,” “urinary catheterization,” “urinary catheters,” “urinary tract infections,” “CAUTI,” and “catheter associated urinary tract infections” and filtered for articles containing the MeSHs “intensive care unit” and “ICU.” Supplemental Figure 1 details the search, yielding 102 studies for CLABSI and 28 studies for CAUTI, including 7 studies with CLABSI and CAUTI interventions.
Eligibility Criteria Review
We included randomized and nonrandomized studies that implemented at least 1 intervention to prevent CLABSI or CAUTI in an adult ICU setting and reported the preintervention or control group data to compare with the postintervention data. We excluded general ward, outpatient/ambulatory, and neonatal/pediatric settings. Interventions to prevent CLABSI or CAUTI were included. We excluded interventions focused on diagnosis or treatment or those that lacked adequate description of the intervention for replication. Studies with interventions that are no longer standard of care in the United States (US) were excluded, as were studies not available in English.
Primary Outcomes for Central Vascular Catheter Infection
- CLABSI: A lab-confirmed bloodstream infection in a patient who has had a central line for at least 48 hours on the date of the development of the bloodstream infection and without another known source of infection. We included studies that reported CLABSIs per 1000 central line days or those that provided data to permit calculation of this ratio. This measure is similar to current National Healthcare Safety Network (NHSN) surveillance definitions.22
- Catheter-related bloodstream infection (CRBSI): A lab-confirmed bloodstream infection attributed to an intravascular catheter by a quantitative culture of the catheter tip or by differences in growth between catheter and peripheral venipuncture blood culture specimens.35 This microbiologic definition of a central line bloodstream infection was often used prior to NHSN reporting, with rates provided as the number of CRBSIs per 1000 central line days.
Primary Outcome for Urinary Catheter Infection
- CAUTI: Urinary tract infection occurring in patients during or after the recent use of an indwelling urinary catheter. We included studies that reported CAUTIs per 1000 urinary catheter days or those that provided data to permit calculation of this ratio (similar to the current NHSN surveillance definitions).22 We excluded studies where CAUTI was defined as bacteriuria alone, without symptoms.
- Central line utilization ratio: The device utilization ratio (DUR) measure of central line use is calculated as central line days divided by patient days.
- Urinary catheter utilization ratio: The DUR measure of urinary catheter use is calculated as indwelling urinary catheter days divided by patient days, as used in NHSN surveillance, excluding other catheter types.22 We excluded other measures of urinary catheter use because of a large variation in definitions, which limits the ability to compare measures across studies.
Data Synthesis and Analysis
Information on the ICU and intervention type, intervention components, outcomes, and whether interventions were in use prior to the study was abstracted by CAUTI and CLABSI experts (JM and PKP) and confirmed by a second author.
We compared interventions found in the literature to components of the previously published urinary catheter “life cycle,” a conceptual model used to organize and prioritize interventions for a reduction in CAUTI (Figure 1).36
Conceptual Model for Disrupting the Life Cycle of a Catheter
Our data analysis demonstrated that components of the urinary catheter life cycle (Figure 1) were useful and could be applied to vascular catheters, but changes were needed to make the model more valuable to hospitalists implementing CLABSI and CAUTI prevention interventions. We found that the previously named stage 1 (catheter placement) is better described in 2 stages: stage 0, avoid catheter if possible, and stage 1, ensure aseptic placement. Additionally, we tailored the model to include actionable language, describing ways to disrupt the life cycle. Finally, we added a component to represent interventions to improve implementation and sustainability, such as auditing compliance and timely feedback to clinicians. Thus, we introduce a new conceptual model, “Disrupting the Life Cycle of a Catheter” (Figure 2)
Central Vascular Catheter Interventional Study Results
Characteristics of Included Central Vascular Catheter Infection Studies
Of the 102 central vascular catheter (CVC) studies that met the inclusion criteria (reporting outcomes for 105 intervention cohorts), 59 studies10,14,16,24-27,38-89 reporting outcomes for 61 intervention cohorts were performed in the US. Study designs included 14 randomized controlled trials (RCTs)48,64,68,74,79,90-98 and 88 before–after studies (Appendix Table 1). 10,14,16,24-27,33,38-47,49-63,69-73,75-78,80-89,99-131 Many RCTs evaluated antimicrobial products (CVCs, hubs, bathing) as interventions,48,68,74,90-95,97,98 but a few RCTs studied interventions64,79,93 impacting catheter care or use (Appendix Table 1). Fifty-one studies took place in tertiary care hospitals and 55 in academic hospitals. Thirty-one studies were multicenter; the largest included 792 hospitals and 1071 ICUs.24 ICU bed size ranged from 5 to 59.
CVC Study Outcomes
Sixty-three studies reported CLABSI outcomes, and 39 reported CRBSI outcomes (Table 2). Many studies had preintervention or control rates above the 2013 NHSN 75th percentiles,22 which varied by ICU type. Preintervention or control infection rates per 1000 catheter days varied widely (means: CLABSI 7.5, CRBSI 6.3); US studies reported ranges of 1.1 to 12.1 CLABSI and 1.2 to 11.0 CRBSI per 1000 catheter days; non-US studies reported ranges of 1.4 to 45.9 CLABSI and 1.6 to 22.7 CRBSI per 1000 catheter days. Postintervention rates varied widely, with overall means of 2.8 CLABSI and 2.5 CRBSI per 1000 catheter days, including US study ranges of 0 to 8.9 CLABSI and 0 to 5.4 CRBSI, and non-US study ranges of 0 to 17.1 CLABSI and 0 to 15.9 CRBSI.
Central line DURs were reported in only 5 studies; 3 reported decreased postintervention DURs (2 with statistical significance), with a mean 11.7% reduction (Table 2).
CVC study interventions are summarized in Table 1, categorized by catheter life cycle component (Figure 2). Thirty-two included studies used a single intervention to prevent CVC infection. Interventions to avoid placement when possible were infrequent. Insertion-stage interventions were common and included avoiding the femoral site during placement, ensuring maximal sterile barriers, and chlorhexidine skin preparation. Standardizing basic products for central line insertion was often done by providing ICUs with a CLABSI insertion kit or stocked cart. In some studies, this was implemented prior to the intervention, and in others, the kit or cart itself was the intervention. Maintenance-stage interventions included scrubbing the hub prior to use, replacing wet or soiled dressings, accessing the catheter with sterile devices, and performing aseptic dressing changes. A recent systematic review and meta-analysis of CVC infection prevention studies indicated that implementing care bundles and/or checklists appears to yield stronger risk reductions than interventions without these components.132 The most common catheter removal interventions were daily audits of line removal and CLABSI rounds focused on ongoing catheter necessity.
Common implementation and sustainability interventions included outcome surveillance, such as feedback on CLABSI, and socio-adaptive interventions to prompt improvements in patient safety culture. Process and outcome surveillance as interventions were implemented in about one-quarter of the studies reviewed (AppendixTable 1).
CAUTI Interventional Study Results
Characteristics of Included CAUTI Studies
Of the 28 CAUTI studies that met the inclusion criteria (reporting outcomes for 30 intervention cohorts), 14 studies (reporting outcomes for 16 intervention cohorts) were performed in the US.28,34,53,66,68,133-141 Study designs included 2 RCTs (focused on urinary catheter avoidance or removal142 and chlorhexidine bathing68) and 26 nonrandomized, before–after studies28,30,33,34,53,66,109,114-116,133-141,143-149 (Appendix Table 1). The number of hospitals per study varied from 1 to 53, with the majority being single-hospital interventions.
CAUTI Study Outcomes
All 28 studies reported CAUTIs per 1000 catheter days for both intervention and comparison groups (Table 2). Preintervention or control CAUTI rates varied widely, with an overall mean of 12.5 CAUTIs per 1000 catheter days; US studies reported a range from 1.4 to 15.8 CAUTIs per 1000 catheter days; non-US studies reported a range from 0.8 to 90.1 CAUTIs per 1000 catheter days. Many studies had preintervention or control rates above the 2013 NHSN 75th percentiles.22 Postintervention CAUTI rates varied widely, with an overall mean of 7.0 CAUTIs per 1000 catheter days, including a US study range from 0 to 11.2 and a non-US study range from 1.9 to 65.7.
Overall (Table 2), 27 of the 30 intervention cohorts described in the 28 studies reported fewer CAUTIs, including all ICU types. Lower postintervention CAUTI rates were reported in 25 studies, with a mean 49.4% reduction, including 11 statistically significant reductions; many studies did not report the level of statistical significance or described inadequate power to detect a significant change (Table 2).
Urinary catheter utilization rates were reported for 11 studies (Table 2). A decreased urinary catheter utilization rate was reported in 7 studies (4 with statistically signficiant reductions), with a mean 16% reduction (Table 2). Other outcomes included cost savings, the potential for unintended negative outcomes, and clinician compliance with intervention components. Positive cost savings were reported in 5 studies.30,34,133,141,149
Of the 28 included CAUTI prevention studies, only 5 studied single interventions. Interventions were categorized in Table 1 by “life cycle” stages or as interventions to improve implementation and sustainability (Figure 2). Interventions to restrict indwelling urinary catheter use were common, including creating lists of approved indications selected by unit or hospital policy and requiring catheter orders with approved indications. Eight studies published approved indication lists.28,34,133-135,138,142,146 Although several studies describe the encouragement and use of bladder scanners and urinary catheter alternatives, none described purchasing these catheter alternatives.
Interventions to avoid indwelling urinary catheters included education about external catheters,28,34,109,133,140,144-146 urinary retention protocols,34,144,135,141 and bladder scanner simulation training.133 Interventions to improve aseptic insertion28,34,66,109,116,139-141-143-146,150 and maintenance care28,34,66,109,116,133,135,136,139-141,143-146,150 of urinary catheters were common. Four studies used a standardized urinary catheter kit or cart,28,34,139,142 and 2 studies used a commercial urinary catheter securement device.34,140 A CAUTI bundle checklist in daily patient care rounds was tested in 3 studies (Table 1).66,136,150 Reminder and stop order strategies, with the potential to reduce CAUTI rates by >50%,151 were included in 15 studies, with inteventions such as nurse-empowered stop orders. Several implementation and sustainability interventions were described, including socio-adaptive strategies such as holding multidisciplinary meetings to obtain unit or clinician feedback to inform design and improve buy-in and providing frequent feedback to ICU clinicians, including audits of catheter use appropriateness and catheter-associated infections.
This extensive literature review yielded a large body of literature demonstrating success in preventing CLABSI and CAUTI in all types of adult ICUs, including in general medical and surgical ICUs and in specialized units with historically higher rates, such as trauma, burn, and neurosurgical. Reported reductions in catheter infections were impressive (>65% for CLABSI or CRBSI and nearly 50% for CAUTI), though several studies had limited power to detect statistical significance. DURs were reported more rarely (particularly for vascular catheters) and often without power to detect statistical significance. Nevertheless, 7 studies reported reduced urinary catheter use (16% mean reduction), which would be anticipated to be clinically significant.
The conceptual model introduced for “Disrupting the Life Cycle of a Catheter” (Figure 2) can be a helpful tool for hospitalists and intensivists to assess and prioritize potential strategies for reducing catheter-associated infections. This study’s results indicate that CLABSI prevention studies often used interventions that optimize best practices during aseptic insertion and maintenance, but few studies emphasized reducing inappropriate central line use. Conversely, CAUTI prevention often targeted avoiding placement and prompting the removal of urinary catheters, with fewer studies evaluating innovative products or technical skill advancement for aseptic insertion or maintenance, though educational interventions to standardize aseptic catheter use were common. Recently, recommendations for reducing the inappropriate use of urinary catheters and intravenous catheters, including scenarios common in ICUs, were developed by using the rigorous RAND/UCLA Appropriateness Method152,153; these resources may be helpful to hospitalists designing and implementing interventions to reduce catheter use.
In reviewing the US studies of 5 units demonstrating the greatest success in preventing CLABSI56,62,65,78,83 and CAUTI,28,34,66,134 several shared features emerged. Interventions that addressed multiple steps within the life cycle of a catheter (avoidance, insertion, maintenance, and removal) were common. Previous work has shown that assuring compliance in infection prevention efforts is a key to success,154 and in both CLABSI and CAUTI studies, auditing was included in these successful interventions. Specifically for CLABSI, the checklist, a central quality improvement tool, was frequently associated with success. Unique to CAUTI, engaging a multidisciplinary team including nurse leadership seemed critical to optimize implementation and sustainability efforts. In addition, a focus on stage 3 (removal), including protocols to remove by default, was associated with success in CAUTI studies.
Our review was limited by a frequent lack of reporting of statistical significance or by inadequate power to detect a significant change and great variety. The ability to compare the impact of specific interventions is limited because studies varied greatly with respect to the type of intervention, duration of data collection, and outcomes assessed. We also anticipate that successful interventions are more likely to be published than are trials without success. Strengths include the use of a rigorous search process and the inclusion and review of several types of interventions implemented in ICUs.
In conclusion, despite high catheter use in ICUs, the literature includes many successful interventions for the prevention of vascular and urinary catheter infections in multiple ICU types. This review indicates that targeting multiple steps within the life cycle of a catheter, particularly when combined with interventions to optimize implementation and sustainability, can improve success in reducing CLABSI and CAUTI in the ICU.
The authors thank all members of the National Project Team for the AHRQ Safety Program for Intensive Care Units: Preventing CLABSI and CAUTI.
Agency for Healthcare Research and Quality (AHRQ) contract #HHSP233201500016I/HHSP23337002T provided funding for this study. J.M.’s other research is funded by AHRQ (2R01HS018334-04), the NIH-LRP program, the VA National Center for Patient Safety, VA Ann Arbor Patient Safety Center of Inquiry, the Health Research and Educational Trust, American Hospital Association and the Centers for Disease Control and Prevention. The findings and conclusions in this report are those of the authors and do not necessarily represent those of the sponsor, the Agency for Healthcare Research and Quality, or the US Department of Veterans Affairs. All authors report no conflicts of interest relevant to this article.