Catheters and Infection Prevention

In this issue we take a look at steps clinicians can take to control and prevent infections relating to both catheter-related bloodstream infections (CR-BSIs) and urinary tract infections (UTIs).

Fighting CR-BSIs

Catheter-related bloodstream infections (CR-BSIs) occur when bacteria grow in an intravenous central line and spread to the patients bloodstream. According to statistics from the Centers for Disease Control and Prevention (CDC), nearly 1 in 5 patients who contract this kind of infection dies from it. Central venous catheters (CVCs) are being increasingly used in inpatient and outpatient settings to provide long-term venous access. CVCs disrupt the integrity of the skin, making infection with bacteria and/or fungi possible. Infection may spread to the bloodstream (bacteremia) and hemodynamic changes and organ dysfunction (severe sepsis) may ensue, possibly leading to death. Approximately 90 percent of the catheter-related bloodstream infections (BSIs) occur with CVCs.1

Forty-eight percent of ICU patients have central venous catheters, accounting for 15 million central venous catheter-days per year in ICUs. Studies of catheter-related bloodstream infections that control for the underlying severity of illness suggest that attributable mortality for these infections is between 4 percent and 20 percent. Thus, it is estimated that between 500 and 4,000 patients in the U.S. die annually due to bloodstream infections.2 In addition, nosocomial bloodstream infections prolong hospitalization by a mean of seven days. Estimates of attributable cost per bloodstream infection are estimated to be between $3,700 to $29,000.3

Care bundles, in general, are groupings of best practices with respect to a disease process that individually improve care, but when applied together result in substantially greater improvement. The science supporting the bundle components is sufficiently established to be considered standard of care. The Central Line Bundle, as promulgated by the Institute for Healthcare Improvement (IHI), 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.

The key components of the IHIs Central Line Bundle are:

• Hand hygiene 

• Maximal barrier precautions upon insertion 

• Chlorhexidine skin antisepsis 

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

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

References:

1. Mermel LA. Prevention of intravascular catheter-related infections. Annals Intern Med. March 2000;132(5):391-402.

2. Soufir L, Timsit JF, Mahe C, Carlet J, Regnier B, and Chevret S. Attributable morbidity and mortality of catheter-related septicemia in critically ill patients: a matched, risk-adjusted, cohort study. Infect Control Hosp Epidemiol. June 1999. 20(6):396-401.

3. Ibid.

The Latest Data on CR-BSIs from the Medical Literature

Heres a look at recent studies from the medical literature.

1. Warren DK, Cosgrove SE, Diekema DJ, Zuccotti G, Climo MW, Bolon MK, Tokars JI, Noskin GA, Wong ES, Sepkowitz KA, Herwaldt LA, Perl TM, Solomon SL, Fraser VJ. A multi-center intervention to prevent catheter-associated bloodstream infections. Infect Control Hosp Epidemiol. July 2006;27(7):662-9.

Abstract: Education-based interventions can reduce the incidence of catheter-associated bloodstream infection. The generalizability of findings from single-center studies is limited.

Objective: To assess the effect of a multi-center intervention to prevent catheter-associated bloodstream infections. Design: An observational study with a planned intervention.

Setting: Twelve intensive care units and one bone marrow transplantation unit at six academic medical centers. Patients: Patients admitted during the study period. Intervention: Updates of written policies, distribution of a 9-page self-study module with accompanying pretest and posttest, didactic lectures, and incorporation into practice of evidence-based guidelines regarding central venous catheter (CVC) insertion and care. Measurements: Standard data collection tools and definitions were used to measure the process of care (i.e., the proportion of non-tunneled catheters inserted into the femoral vein and the condition of the CVC insertion site dressing for both tunneled and non-tunneled catheters) and the incidence of catheter-associated bloodstream infection.

Results: Between the pre-intervention period and the post-intervention period, the percentage of CVCs inserted into the femoral vein decreased from 12.9 percent to 9.4 percent (relative ratio, 0.73; 95 percent confidence interval [CI], 0.61- 0.88); the total proportion of catheter insertion site dressings properly dated increased from 26.6 percent to 34.4 percent (relative ratio, 1.29; 95 percent CI, 1.17-1.42), and the overall rate of catheter-associated bloodstream infections decreased from 11.2 to 8.9 infections per 1,000 catheter-days (relative rate, 0.79; 95 percent CI, 0.67-0.93). The effect of the intervention varied among individual units.

Conclusions: An education-based intervention that uses evidence-based practices can be successfully implemented in a diverse group of medical and surgical units and reduce catheter-associated bloodstream infection rates.

2. Warren DK, Quadir WW, Hollenbeak CS, Elward AM, Cox MJ, Fraser VJ. Attributable cost of catheter-associated bloodstream infections among intensive care patients in a non-teaching hospital. Crit Care Med. Aug. 2006;34(8):2084-9.

Abstract: Objective: To determine the attributable cost and length of stay of intensive care unit (ICU)-acquired, catheter-associated bloodstream infections from a hospital-based cost perspective, after adjusting for potential confounders. Design: Patients admitted to the ICU between Jan. 19, 1998, and July 31, 2000, were observed prospectively for the occurrence of catheter-associated bloodstream infections. Hospital costs were obtained from the hospital cost accounting database. Setting: The medical and surgical ICUs at a 500-bed suburban, tertiary care hospital.

Patients: Patients requiring central venous catheterization while in the ICU. Interventions: None. Measurements and main results: We measured occurrence of catheter-associated bloodstream infection, inhospital mortality rate, total ICU and hospital lengths of stay, and total hospital costs. Catheter-associated bloodstream infection occurred in 41 of 1,132 patients (3.6 cases per 1000 catheter days). Patients with catheter-associated bloodstream infection had significantly higher unadjusted ICU length of stay (median, 24 vs. 5 days; p < .001), hospital length of stay (median, 45 vs. 11 days; p <.001), mortality rate (21 [51 percent] vs. 301 [28 percent], p =.001), and total hospital costs ($83,544 vs. $23,803, p <.001). Controlling for other factors that may affect costs and lengths of stay, catheter-associated bloodstream infections resulted in an attributable cost of $11,971 (95 percent confidence interval, $6,732-$18,352), ICU length of stay of 2.41 days (95 percent confidence interval, 0.08-3.09 days), and hospital length of stay of 7.54 days (95 percent confidence interval, 3.99-11.09 days).

Conclusions: Patients with catheter-associated bloodstream infection had significantly longer ICU and hospital lengths of stay, with higher unadjusted total mortality rate and hospital cost compared with uninfected patients. After adjusting for underlying severity of illness, the attributable cost of catheter-associated bloodstream infection was approximately $11,971.

3. Young EM, Commiskey ML, Wilson SJ. Translating evidence into practice to prevent central venous catheter-associated bloodstream infections: a systems-based intervention. Am J Infect Control. Oct. 2006;34(8):503-6.

Abstract: Background: The central venous catheter (CVC) is a necessary, yet inherently risky, modern medical device. We aimed to carry out a systems-based intervention designed to facilitate the use of maximal sterile barrier precautions and the use of chlorhexidine for skin antisepsis during insertion of CVC.

Methods: All patients in whom a CVC was inserted at a medical-surgical intensive care unit at a university-affiliated public hospital were included in a before-after trial. The standard CVC kit in routine use before the intervention included a small sterile drape (24 by 36) and 10 percent povidone-iodine for skin antisepsis. We special ordered a customized kit that, instead, included a large sterile drape (41 by 55) and 2 percent chlorhexidine gluconate in 70 percent isopropyl alcohol. Both the standard kit in use before the intervention and the customized kit included identical CVCs. Baseline data included the quarterly CVC-associated bloodstream infection (BSI) rates during the 15 months before the intervention. Comparison data included the quarterly CVC associated BSI rates during the 15 months after we instituted exclusive use of the customized kit.

Results: The mean quarterly CVC-associated BSI rate decreased from a baseline of 11.3 per 1000 CVC-days before the intervention to 3.7 per 1000 CVC-days after the intervention (P < .01). Assuming direct costs of at least 10,000 dollars per CVC-associated BSI, we calculated resultant annualized savings to the hospital of approximately 350,000 dollars.

Conclusion: Infection control interventions that rely on voluntary changes in human behavior, despite the best intentions of us all, are often unsuccessful. We have demonstrated that a systems-based intervention led to a sustained decrease in the CVC-associated BSI rate, thereby resulting in improved patient safety and decreased cost of care.

4. Larson EL, Cimiotti JP, Haas J, Nesin M, Allen A, Della-Latta P, Saiman L. Gram-negative bacilli associated with catheter-associated and non-catheter-associated bloodstream infections and hand carriage by healthcare workers in neonatal intensive care units. Pediatr Crit Care Med. July 2005;6(4):457-61.

Abstract: Objective: Bloodstream infections caused by Gram-negative bacilli are a substantial cause of morbidity and mortality in infants in neonatal intensive care units. This study describes the species of Gramnegative bacilli causing bloodstream infections in two neonatal intensive care units, compares characteristics of catheter-related and non-catheter- related bloodstream infections, and compares species and antibiotic resistance patterns of these organisms with those isolated from the hands of nurses working in the same neonatal intensive care units.

Setting: Two high-risk neonatal intensive care units. Patients: Neonates hospitalized for >or =24 hrs. Interventions: Prospective surveillance for bloodstream infections was performed in two neonatal intensive care units from March 2001 to January 2003. Hand cultures were obtained quarterly from participating nurses immediately after they performed hand hygiene.

Measurements and results: There were 298 episodes of bloodstream infections among 2,935 admissions (5.75 episodes per 1,000 patient-days); 77 of 298 (26 percent) episodes were caused by Gramnegative bacilli. Among these, 47 (61.0 percent) were catheter-related bloodstream infections (2.61 episodes per 1,000 catheter-days). Eleven and 24 Gram-negative bacilli species were isolated from neonates and nurses, respectively. The most common Gram-negative bacilli causing bloodstream infections were Klebsiella pneumoniae (38.7 percent), Escherichia coli (21.2 percent), Enterobacter cloacae (11.2 percent), and Serratia marcescens (11.2 percent). In contrast, Acinetobacter lwoffi (18.1 percent), K. pneumoniae (11.7 percent), E. cloacae (10.6 percent), K. oxytoca (10.6 percent), and Pseudomonas spp. (7.4 percent) were most commonly isolated from hands of nurses. E. coli, P. aeruginosa, E. cloacae, and E. aerogenes were significantly more likely to cause bloodstream infections than to be isolated from nurses hands (all p < .001). Although 39 percent of bloodstream infections were non-catheter-related, there were no significant differences in types of organisms or antimicrobial resistance patterns between catheter-related bloodstream infections and non-catheter-related bloodstream infections (all p > or = .35). Resistance patterns were similar between Gram-negative bacilli isolates from neonates and nurses hands except for a significantly higher proportion of resistance to cefotaxime and gentamicin among neonatal isolates of K. pneumoniae (p < .05).

Conclusions: Gram-negative bacilli species isolated from neonatal bloodstream infections and nurses hands varied significantly. Clean hands of providers are an unlikely source of endemic Gram-negative bacilli, suggesting that prevention strategies should focus more on control of endogenous neonatal flora or environmental sources.

5. Wolfenden LL, Anderson G, Veledar E, Srinivasan A. Catheter-associated bloodstream infections in 2 long-term acute care hospitals. Infect Control Hosp Epidemiol. Jan. 2007;28(1):105-6. No abstract available.

6. Kidd KM, Sinkowitz-Cochran RL, Giblin TB, Tokars JI, Cardo DM, Solomon SL. Barriers to and facilitators of implementing an intervention to reduce the incidence of catheter-associated bloodstream infections. Infect Control Hosp Epidemiol. 2007 Jan;28(1):103-5. No abstract available. 

Case Study

Decreasing Central Line Infections with Evidence-Based Practice

By Jeanette M. Meyer, MSN, RN, CCRN, CCNS, PCCN, Banner Desert Hospital 

Problem: Increase in infections noted in central venous catheter (CVC) lines in the adult medical/surgical intensive care unit (benchmark 3.2/1,000 device days, 7/1,000 device days noted in one month).

Evidence: CDC and IHI literature on decreasing CVC infections was gathered and reviewed.

Strategy: National Institute of Health Services (NIHS) benchmarks were utilized. Initial data was gathered about the nature of central line infections via a central line audit tool. This tool included aspects such as patient symptoms, cultures and culture sites, and the date the central line was placed. This evidence was then used to create a central line insertion safety checklist to use during all central line insertions.

Practice change: Aspects of the IHI Central Line Bundle were incorporated into practice with safety checklist reminders, to include: handwashing, site preparation with chlorhexidine, maximum barriers, and sterile field maintenance. The utilization of the central line insertion safety checklist provided a visual prompt, as well as a screening tool of whether these safety aspects were done.

Evaluation: The central line audit tool was again utilized to track the number and nature of infections after the central line bundle and safety checklist were instituted.

Results: Seven consecutive months with no CVC infections were noted following the practice change. Only one month went over the benchmark following institution of the checklist.

Recommendations: Continue utilizing central line bundle and safety checklist and initiate additional aspects of the IHI Central Line Bundle by adding in screening for line necessity. Examine each specific infection that occurs in detail to attempt to determine causative factors. Create specific criteria for evaluating line necessity and use this criteria in determining whether to maintain or discontinue central lines.

Case Study

Eliminating Central Line-Related Bloodstream Infections with Bundle Compliance

By Michael Westley, MD, FCCP Shirley Sherman, RN Susan Busteed, project manager All of Virginia Mason Medical Center, Seattle

Goal: Eliminate device-related central line blood stream infections to zero events.

Measures: Rate of bloodstream infections related to central venous devices per 1,000 patient device days; compliance with bundle (checklist of behaviors / procedural documentation audit).

Changes: Revised organization policy to include maximum barrier protection; developed a line cart that had all necessary supplies; developed checklist for pre, during and post procedure standard work; transducer kit placed on all central line (CL) carts (used to prevent accidental arterial cannulation); placed a picture flow sheet on all CL carts to highlight elements of Central Line Bundle; picture flow sheet for transducer/manometer application was developed and posted on CL carts; specified RN staff observer; procedural pause; Stop the Line Patient Safety Alert Process; documentation role (audit/checklist); revised and taught proper use of new skin preparation (chlorhexidine); perform monthly in-service for internal medicine house staff and as needed with surgery service (action by medical director); standardize dressing care and changes; annual training competency (newly added); access/maintenance of needleless device protocol (developed and reviewed by staff); devised successive checks: Daily multidisciplinary goal sheet, walking rounds, and charge nurse report form; reviewed each line infection as sentinel event to assess patterns; spread improvement work to hospital-wide initiative level by providing standard work (checklist; cart; roles of staff; algorithm for CCU/non-CCU patients); placed graphs depicting line infection in prominent locations; house-wide education assisted by PowerPoint presentation (created by physician leader); celebrated early and subsequent success at committee/staff meetings, or via organizations newsletter, and posted dashboards of graphs/case studies